Sony MDS-JE510 dead display

[denisten73]

Hi to everyone here. I'm new to the forum and I have a Sony Mds-je 510 minidisc deck which is now dead. It was working fine,but was showing blinking 'standby' when you switch it on. This is a sign for a weak battery and I decided to replace it. It all went smooth, I disconnected the three ribbon cables and ac cord from the main board, pulled it out of the casing, desoldered the old battery, soldered the new one and put back the main board in place. When I switched it on - disaster! No signs of life at all. I went for a cigarette, thinking what might be the problem and when I came back I saw I forgot to connect all the ribbon cables. Lol, easy! But I didn't notice that I left the deck plugged in the outlet. So, after connecting the ribbon cables , probably I have shorted something. Now I have only the standby light, it goes to green when I switch it on and to red when I switch it back off. The loading and ejecting works, but the disc doesn't spin, no display and no buttons working. I have checked B+ on pin 64, 3.3 V and B- on pin 56, -32.6V of IC 701, the display ic, as per service manual, they are there.

Any help will be highly appreciated, thanks.

Stan

[NGY]

Hi Stan, welcome to the forums.

 

22 hours ago, denisten73 said:

Now I have only the standby light, it goes to green when I switch it on and to red when I switch it back off. The loading and ejecting works

These are all good signs of the device not yet being fully dead. That the power button works shows your MCU is alive - it is sensing some of the buttons and can control the standby/power on led, therefore, it seems it is not blocked by a fault somewhere, that would cause the MCU forcing the device stay in Standby. That the disc load/eject works shows that your BD board is alive (might have some faults though - to be figured out later on).

Let's begin with the trivial stuff:

- I would first check the two ribbons that connect the drive to the main board. On the 500/510 decks it is fairly easy to seat one of the ribbons the wrong way, at the main board end. The wider one is pretty straigthforward (i.e., short enough, and folded sharply), but the other one can be plugged 180 degrees twisted around (I faced this issue a couple of times, and luckily those decks always survived this mistake). Both ribbons' contacts should face the rear of the deck, not the front. In other words, the ribbon side with the writing on it is facing the rear, the plain white side is facing the front.

- second I would check the front panel's ribbon, for contacts peeling off like this, or being damaged otherwise:

-  then there is a display/controls check mode you can try, to see whether or not your display driver is alive, and/or the MCU can sense all other buttons/switches, as well as the IR sensor. Turn the deck off with the switch on the back panel, press and keep the AMS knob and the record button pushed, then switch the deck back on. The display should lit all segments, then by pressing each buttons one by one, you can turn off the segments one by one. Once all done, other tests can be performed, following the instructions appearing on the display.

Let us know the outcomes of these checks, and we can take it from there.

[denisten73]

19 hours ago, NGY said:

Hi Stan, welcome to the forums.

 

These are all good signs of the device not yet being fully dead. That the power button works shows your MCU is alive - it is sensing some of the buttons and can control the standby/power on led, therefore, it seems it is not blocked by a fault somewhere, that would cause the MCU forcing the device stay in Standby. That the disc load/eject works shows that your BD board is alive (might have some faults though - to be figured out later on).

Let's begin with the trivial stuff:

- I would first check the two ribbons that connect the drive to the main board. On the 500/510 decks it is fairly easy to seat one of the ribbons the wrong way, at the main board end. The wider one is pretty straigthforward (i.e., short enough, and folded sharply), but the other one can be plugged 180 degrees twisted around (I faced this issue a couple of times, and luckily those decks always survived this mistake). Both ribbons' contacts should face the rear of the deck, not the front. In other words, the ribbon side with the writing on it is facing the rear, the plain white side is facing the front.

- second I would check the front panel's ribbon, for contacts peeling off like this, or being damaged otherwise:

-  then there is a display/controls check mode you can try, to see whether or not your display driver is alive, and/or the MCU can sense all other buttons/switches, as well as the IR sensor. Turn the deck off with the switch on the back panel, press and keep the AMS knob and the record button pushed, then switch the deck back on. The display should lit all segments, then by pressing each buttons one by one, you can turn off the segments one by one. Once all done, other tests can be performed, following the instructions appearing on the display.

Let us know the outcomes of these checks, and we can take it from there.

Thanks NGY, the cables are facing backwards as it should be. The rest i will check once i have some free time and i will post the results immediately. Cheers!

[denisten73]

On 1/18/2021 at 6:11 PM, NGY said:

 

- second I would check the front panel's ribbon, for contacts peeling off like this, or being damaged otherwise:

-  then there is a display/controls check mode you can try, to see whether or not your display driver is alive, and/or the MCU can sense all other buttons/switches, as well as the IR sensor.

Checked the cable - it is ok. Tried to do the check mode, but nothing happens, the display is dead.

[NGY]

9 hours ago, denisten73 said:

Tried to do the check mode, but nothing happens, the display is dead.

That's no good news then. Just for a quick countercheck, is this the same when you try to enter regular Service Mode?

If you can enter Service Mode we can do some further checks. If you cannot, we must do some guessing and trial-and-error.

[In that case - as always when we try to fix something remotely, some questions or hints may make no sense to you (that is, not a fault at your end :-) ), but please try to follow the path. I am not saying my method is "the" way, but what I write here is exactly how I would try to work if the faulty device was in front of me. As I don't see the machine itself, I can only work from what feedback I get from you, therefore it is important we are on the same page. And please forgive me if this small "preword" is completely unnecessary for you - I have already run into cases here when the person at the other end of the line was moving on a totally different path (of his thougths), that resulted a bit of chaos in analyzing the results and possible causes, that led to an unsuccessful repair process. Your questions, ideas and other important feedback are always welcome though.]

Back to your 510: I am trying to separate these possible faults:

- MCU - the main processor has some of its I/O ports directly wired to those ribbon connectors. As you wrote above, misalignment of a cable under power might cause some trouble. Having said that, these I/O ports are protected to a certain extent (with pull up resistors, and/or internal latches, etc.), so there is a good chance the MCU is still undamaged.

- display - as you noticed, the VFD is driven by a special IC. This IC receives data from the MCU on a serial line, but even if that line is damaged, the rest of the deck might still be operable, independently from a dark display.

- drive mechanism - partly controlled by the BD board logic, partly by the MCU, let's see what works and what does not.

- OP - one of the most sensitive parts is the optical pick-up, highly sensitive to ESD damages. A broken OP - among others - can for example cause the loaded disc not spinning up.

- rest of the MB - there are power regulators, analogue audio and digital signal switching circuitries there - I would not expect any of them being damaged, but may need some checks too.

So our next step: you wrote you could  eject a loaded disc. If the Eject button works, so should the FF/FR, Stop and Record buttons do, because they are on the same MCU control line. Now, if you can enter service mode, even with a dark display, you should be able to load a disc, and try to move the sled back and forth, as well as to lower the OWH onto the disc as if it was in rec mode, even if the disc is not spun up. Then pressing the Stop button would then lift the OWH. Please let us know if these work.

Next: in normal mode (Power led green) load a disc, set the Timer switch to Rec, set the source selector switch to Analogue, then unplug the deck (or use the switch on the back panel). After 10...20 seconds, plug the AC cord back in, and observe what the drive does: i.e., it moves the head into rec position, or just ejects the disc after a while, etc. Let us know what you find.

So much for now. If there are no results I am expecting here, we can only possibly move forward if you can have access to another, similar deck - more on that later.

[denisten73]

On 1/20/2021 at 5:44 PM, NGY said:

That's no good news then. Just for a quick countercheck, is this the same when you try to enter regular Service Mode?

Thank you NGY. I have tried regular Service Mode before, but when i saw the dark display, i thought it is not in SM. I will try again and will do all the steps you have proposed, probably at the weekend.

[denisten73]

Here is what I have found:

- all buttons work in normal operation mode, my mistake on initial evaluation was to use a blank disc(this deck suffers from "TOC writing/blank disc" problem, and I was afraid not to erase some of my recorded discs. No content on the disc, no play button action, simple. Sorry about that. Play, pause, rec ,stop, FF, FR, AMS -all working

- all buttons work in regular Service mode too

-in Rec timer scenario all works as you described it, the OWH is lowered and disc is spinning.

I had similar fully working deck  MDS-JE320 which I sold. I have an MDS-JE530 too, but I think it is a bit different from JE510. 

That is so far, I hope I will be able to bring back to life the display.

[NGY]

Great job. You sorted out most of the possible errors but the dark display. And a - possibly - laser wear or misadjustment thing waits for being fixed later:

6 hours ago, denisten73 said:

(this deck suffers from "TOC writing/blank disc" problem

Anyhow, let's continue working on the display.

First, let's see if the VFD filaments get their voltage, and if they do, they are not broken. You can measure the filament voltage on the VFD - there must be some AC 3V between the leftmost and rightmost pins (actualy, 3-3 pins). If that voltage is there when the deck is on, unplug the AC cord as well as the front panel ribbon, and measure the filaments in continuity mode (between same pins). Also you can do a visual check - look for those tiny wires across the tube:

You already measured that the system 3.3V gets to the display driver IC, the negative voltage for the cathodes is there too - we are happy with these.

Next thing would be to see if the serial comms lines from the MCU work, but that would call for a data analyzer (or min. a scope). Without any, you can measure at least the Clock line on pin 62, looking for some 3V. Also, a quick check on the Reset line, if the MCU is not disabling the display IC for any reason - expect DC 3.3V on pin 60, if that is OK. (Not much probable, but if the internal oscillator of the driver IC happens to be not working, can also lead to a dark display - a high frequency square wave must be on pin 59).

If everything above are in order, maybe a last check on the front panel ribbon, at both ends, as well as on the ribbon connectors, looking for bent/broken contacts, or any foreign particles stuck inside the socket, etc.. And a weird one: check if all earthing straps, as well as that copper sheet at the bottom side of the front panel are properly connected to the chassis.

If all OK, then I have to stop here, this is all I can do remotely. That 320 would be a great help now, having a (nearly exact) same front panel as the 500/510 (some buttons/resistors missing/different), and a quick swap would tell us if the problem lies on the main board or on the front panel.

[denisten73]

19 hours ago, NGY said:

First, let's see if the VFD filaments get their voltage.......

Next thing would be to see if the serial comms lines from the MCU work, but that would call for a data analyzer (or min. a scope). Without any, you can measure at least the Clock line on pin 62, looking for some 3V. Also, a quick check on the Reset line, if the MCU is not disabling the display IC for any reason - expect DC 3.3V on pin 60, if that is OK. (Not much probable, but if the internal oscillator of the driver IC happens to be not working, can also lead to a dark display - a high frequency square wave must be on pin 59).

There is an AC 3V on the pins of VFD, there is continuity with ribbon cable disconnected and deck turned off too.

I get nothing on Clock line, pin 62. I traced back the line to the mainboard and there is no voltage on pin 11 of CN303 as well. I have the 3,3V on pin 60  and 1.5V on pin 59.

Quote

a high frequency square wave must be on pin 59

I have only a DMM and cannot  check this.

Tomorrow i will dismantle the front panel to visually check the wires of the tube. I am not sure of one thing only:

Quote

19 hours ago, NGY said:

as well as that copper sheet at the bottom side of the front panel

 

Many thanks for your help.

[NGY]

Great to see you are doing a thorough work here. I think your VFD is allright then.

With that, we can narrow it down to the communication problem between the MCU and the VFD IC. It seems the Clock line does not work. It could be at the MCU side, either a silicon damage on that pin, or a firmware blockage (possible reason for the latter, if at all, is not clear to me). It also could be on the display driver IC side, i.e., if there is an internal shunt (burnt circuit) on the chip, that pulls the clock line to ground.

Without the tools mentioned above, it is a bit tricky to figure out which one, but we can get an idea with some creativity. First you need to somehow disconnect the display driver from the MCU, while keeping the rest of the front panel still connected. One way is to disconnect pins 61-62-63 of IC701 by desoldering and lifting 1-1 legs of R722-723-724. Once done, measure again the clock line from the MCU on CN303 as you did before. If still nothing, your MCU is not clocking the serial comms line, means it cannot send data to the display chip. If you see the ~3V, then IC701 is the one to check further. Now, you need to measure if pin 62 is not shortcircuit to ground. Normally, I am using an ESR meter to do such a check, not a DMM (more on the "why" here). As a workaround, you can try using a 1k resistor in series with your DMM probes, and measure the total resistance (with the AC cord pulled off, obviously). If you get ~1k, then the internal circuit behind that pin is probably burnt (then you can go and re-check it without the 1k resistor, you probably will not make it worse). If you see a min. one magnitude higher value, then it should be OK.

Whatever you find, it means the machine will need some replacement parts and a bit of careful SMD soldering job, to get the display back. Or, a donor device, and just swap the needed board.

 

Regarding the "copper sheet" - apologies if I was misleading you. I wrote off the top of my head (as I usually do), and remembered wrongly that particular way of grounding was on the 510's too. It is certainly there on its midi equivalent S38 (see on the photo below), but eventually it looks like there is nothing such on the 510's anymore. The copper strip is soldered to the ground foil of the front panel PCB, then it goes between the chassis and the front bezel. I saw some decks in the past when this little piece was floating above the chassis, not touching it, that caused other problems.

 

EDIT: one more thought, as I am not familar with how the MCU and the display driver IC communicate. It is probable, that when only a static message is shown on the VFD (like "NO DISC"), there is nothing happening on the comms line. Therefore, while measuring the Clock line again, "do something" that would normally change what is displayed - say load a disc, or press the Repeat (or Play Mode) button a few times, etc..

[denisten73]

On 1/24/2021 at 11:16 PM, NGY said:

 

Without the tools mentioned above, it is a bit tricky to figure out which one, but we can get an idea with some creativity. First you need to somehow disconnect the display driver from the MCU, while keeping the rest of the front panel still connected. One way is to disconnect pins 61-62-63 of IC701 by desoldering and lifting 1-1 legs of R722-723-724. Once done, measure again the clock line from the MCU on CN303 as you did before. If still nothing, your MCU is not clocking the serial comms line, means it cannot send data to the display chip. If you see the ~3V, then IC701 is the one to check further. Now, you need to measure if pin 62 is not shortcircuit to ground. Normally, I am using an ESR meter to do such a check, not a DMM (more on the "why" here). As a workaround, you can try using a 1k resistor in series with your DMM probes, and measure the total resistance (with the AC cord pulled off, obviously). If you get ~1k, then the internal circuit behind that pin is probably burnt (then you can go and re-check it without the 1k resistor, you probably will not make it worse). If you see a min. one magnitude higher value, then it should be OK.

Whatever you find, it means the machine will need some replacement parts and a bit of careful SMD soldering job, to get the display back. Or, a donor device, and just swap the needed board.

 

EDIT: one more thought, as I am not familar with how the MCU and the display driver IC communicate. It is probable, that when only a static message is shown on the VFD (like "NO DISC"), there is nothing happening on the comms line. Therefore, while measuring the Clock line again, "do something" that would normally change what is displayed - say load a disc, or press the Repeat (or Play Mode) button a few times, etc..

That will need some more time. When i do it i will post the results. Thank you again.

[denisten73]

On 1/26/2021 at 7:05 PM, denisten73 said:

EDIT: one more thought, as I am not familar with how the MCU and the display driver IC communicate. It is probable, that when only a static message is shown on the VFD (like "NO DISC"), there is nothing happening on the comms line. Therefore, while measuring the Clock line again, "do something" that would normally change what is displayed - say load a disc, or press the Repeat (or Play Mode) button a few times, etc..

I measured again. No voltage when disc is loaded or ejected, Repeat or Play mode are pressed. The only combination when i have something is when the disc is playing and Repeat is pressed - it jumps between 0,01 - 0,02V.

Next i will desolder the resistors and check again.

[denisten73]

On 1/24/2021 at 11:16 PM, NGY said:

One way is to disconnect pins 61-62-63 of IC701 by desoldering and lifting 1-1 legs of R722-723-724. Once done, measure again the clock line from the MCU on CN303 as you did before. If still nothing, your MCU is not clocking the serial comms line, means it cannot send data to the display chip.

I did this and there is still no voltage on pin 11 of CN303. I tried again loading a disc, Play mode , Repeat buttons - still nothing. I guess there is no reason to check pin 62 for  shortcirquit to ground.

[NGY]

8 hours ago, denisten73 said:

I guess there is no reason to check pin 62 for  shortcirquit to ground.

No, you're very probably right. All indications are that the MCU is damaged here.

[NGY]

On 1/24/2021 at 10:16 PM, NGY said:

It is probable, that when only a static message is shown on the VFD (like "NO DISC"), there is nothing happening on the comms line.

For the records: the Clock signal is supposed to be there even with a static display. Just did a quick test on a JE500:

[denisten73]

2 hours ago, NGY said:

No, you're very probably right. All indications are that the MCU is damaged here.

Is there a chance to be something outside the MCU?

[NGY]

I am breaking my head over this ... Here is what we know:

- the deck is operable, but the display

- the VFD tube is intact, so are the related supply voltages

- the front panel ribbon and its sockets are spotless, at both ends

- the MCU is not giving the Clock signal on its FLCLK pin, that is directly wired to CN303 on the main board.

Let's take this last one further, if we can do some more checks there. (For the first three, the only thing I could/would do is to perform all previous checks again, to exclude anything I possibly overlooked.) The "trivial" stuff:

- is there any damage to the main board's copper traces? With the front panel ribbon disconnected (deck powered down), can you measure continuity between pins 71/72/73 of the MCU chip (IC316) and pins 11/9/7 of CN303 respectively? (Please be very careful touching only the proper contacts.)

- is there anything on the main board that can cause the Clock line shortcircuit to ground? With the front panel ribbon disconnected (deck powered down), can you measure some low value resistance between 1) pin 71 of the MCU and ground, also 2) pin 11 of CN303 and ground? (Please see my note above on the "how to" - as you will measure directly on the MCU.)

If all OK, to exclude the MCU being damaged with 100% confidence, we would need another 510 available for a quick swap of the front panels. Possible outcomes then:

- "guest" front panel + your 510: A) display OK = your 510's MCU is allright, dark display = your MCU is damaged

- your 510's front panel + "guest" 510: C) display OK = your front panel is allright, D) dark display = your front panel is damaged

Cases A) and/or D) would then need further investigation for where we did possibly go wrong, but I doubt if either one was the case. Nevertheless, I am certainly always prepared to see the unexpected, and learn something new :-) .

 

EDIT: just a weird idea ... what voltage can you measure on pin 23 of the MCU? First with the deck is ON, then with the deck powered down and waited ~30 seconds (looking for +3.0V ... +3.3V to ground). (Again, please be careful when touching the IC's pin, not to accidentally shortcircuit to the neigbouring one.)

[denisten73]

7 hours ago, NGY said:

the MCU is not giving the Clock signal on its FLCLK pin, that is directly wired to CN303 on the main board.

I found an error in the SM yesterday. On Printed Wiring Board ,page 47-48, if you follow the trace from pin11 of CN303, you will see it goes through JW143 to pin 70 of IC 316, not pin 71. Can you confirm this too, please. I will inspect the mainboard  'physically'. Something else, i found a topic in a forum (sadly i can not findit again now), same model deck, same symptoms. The guy have replaced the diodes, the resistor and some of the capacitors around IC 310 with no results and then suddenly he found out some cold solder joints in the Jumper wires around CN 303. His display came back to life again. It is possible, when i replaced the battery, that something similar happened to my main board too. There was some slight bending of the main board during dismantling, desoldering and soldering the new battery. Actually, i pulled out the main board first to see the battery contacts underneath ,  put it back in and then i did the 'live' ribbon cable connection, before installing the new battery.

[NGY]

2 hours ago, denisten73 said:

some cold solder joints in the Jumper wires around CN 303

True, "cold solder joints" (or "dry joints") are possible - I also posted such errors (like the one here).

However, and it also relates to the possible SM error ...

2 hours ago, denisten73 said:

I found an error in the SM yesterday ... Can you confirm this too, please

... I prefer using my meters to do such checks on the board itself, for a couple of reasons. While Sony SM-s are generally very good quality, some of them are scans only (like the one for 510), not digitized blueprints, means they cannot be zoomed properly and my eyes are too old for following these tiny lines. I have rarely seen errors in Sony MD SMs, the very seldom ones I ever saw were rather in the schematics, not on the PCB prints. And if I have to look for a connection (or the lack of it) beetween point A and B, measuring is the best way, meters won't overlook.

That's why suggested above to perform those two checks, to see if the  serial comms lines' traces from the MCU pins do reach the ribbon connector's contacts properly. But just for you ;-) (no, there is no error in the SM, pin 11 of CN303 goes directly to pin 71 of IC316, via the sole jumper wire of JW143):

also

And, to exclude one "weird" but possible thing, I wanted to see, that after ...

2 hours ago, denisten73 said:

installing the new battery

... the MCU sees the new battery voltage properly. Because if there was an issue there (i.e., reversed polarity, or shorted battery), the MCU would take it as a Reset (see the reset jumper wires, for a forced reset they simply short the battery to ground via R16, being 68 or 100 ohms only), and when the MCU resets what it need to, it probably disables the display too.

[denisten73]

OK, i will do all the checks suggested once again. Sorry for my slow response, but i live in a small appartment and there is no room for my audio experiments when the kids are always home with this awful Covid situation.

I am not sure what do you mean with this:

2 hours ago, NGY said:

And, to exclude one "weird" but possible thing, I wanted to see, that after ...

3 hours ago, denisten73 said:

installing the new battery

... the MCU sees the new battery voltage properly. Because if there was an issue there (i.e., reversed polarity, or shorted battery), the MCU would take it as a Reset (see the reset jumper wires, for a forced reset they simply short the battery to ground via R16, being 68 or 100 ohms only), and when the MCU resets what it need to, it probably disables the display too.

Is it a step in the tests already suggested by you, but not done by me yet , or i have to do something else? As you can sense, English is not my native speaking language, sorry about that too.

[NGY]

Yes, it is one last check I would do - as I wrote above (added as an EDIT): ”what voltage can you measure on pin 23 of the MCU”. This is to clarify everything is OK around the new battery, and the MCU sees it properly too.

[denisten73]

On 1/30/2021 at 12:17 AM, NGY said:

With the front panel ribbon disconnected (deck powered down), can you measure continuity between pins 71/72/73 of the MCU chip (IC316) and pins 11/9/7 of CN303 respectively? (Please be very careful touching only the proper contacts.)

 

Continuity measured - all are OK

 

On 1/30/2021 at 12:17 AM, NGY said:

can you measure some low value resistance between 1) pin 71 of the MCU and ground, also 2) pin 11 of CN303 and ground? (Please see my note above on the "how to" - as you will measure directly on the MCU.)

DMM shows open cirquit in both checks. Sadly i have no other JE510 deck around me.

 

On 1/30/2021 at 12:17 AM, NGY said:

EDIT: just a weird idea ... what voltage can you measure on pin 23 of the MCU? First with the deck is ON, then with the deck powered down and waited ~30 seconds (looking for +3.0V ... +3.3V to ground). (Again, please be careful when touching the IC's pin, not to accidentally shortcircuit to the neigbouring one.)

I have no access to the IC316 pins,it is on the opposite side of the board when the mainboard is mounted. I am afraid to flip it over when everything is connected. I measured on C354 and i have 2.68V when the deck is on and 2.65V 45 seconds after switching it off. It is little bit low, but i guess it is because this new battery was not charged enough.(the deck is unplugged most of the time since the battery was replaced)

I did all other checks again - same results.

 

EDIT: I checked the + lead of the battery when deck turned on and it was same 2.68V. It seems low to me.

[NGY]

On 1/29/2021 at 11:17 PM, NGY said:

- the MCU is not giving the Clock signal on its FLCLK pin, that is directly wired to CN303 on the main board.

OK, let's summarize, how far we got:

- on the main board copper traces of FLCLK/FLDT/FLCS are intact between the MCU and CN303 (so are the solder joints of the respective jumper wires)

- the FLCLK line is not shortcircuit to ground on the main board (for the maximalists: how about the two other lines?)

Based on this and previous findings, we exluded all possible causes for the (otherwise good) Clock signal getting from the MCU to the display IC. My logic tells me it is then the MCU that is responsible for the dark display.

 

22 hours ago, denisten73 said:

 I checked the + lead of the battery when deck turned on and it was same 2.68V. It seems low to me.

The battery gets its regulated charging voltage (3.3V) from IC309 (pin 6). This voltage gets thru a protection diode (~0.6V forward drop) and a current limiting resistor (R316, also drops a tiny bit of voltage when charging), therefore, the 2.68 V you measured seems fully normal to me.

We pretty much depleted all possible ideas here. I could only have one very last (and again "weird") shot on the battery. We know it for sure, that a deck is fully functional (but keeping user settings and unwritten TOC data when powered down) without the battery, or even with a dead battery. What if you desolder the new battery? Would that change anything "'back" then?

[denisten73]

51 minutes ago, NGY said:

We pretty much depleted all possible ideas here. I could only have one very last (and again "weird") shot on the battery. We know it for sure, that a deck is fully functional (but keeping user settings and unwritten TOC data when powered down) without the battery, or even with a dead battery. What if you desolder the new battery? Would that change anything "'back" then?

Of course i will try this. What makes me feel even more silly is that before replacing the battery, i did not check if the deck was functioning as before(it was unused for about two months). I even got rid of the old battery before i tested it. I have never realised i will get in so much troubles with this simple task.

[NGY]

Yeah ... the MDM-3 flavours can be a real PITA sometimes ...

You did quite a few checks/tests, and based on the results, besides the 'deck suffers from "TOC writing/blank disc" problem' I did not feel anything particular to be worried about (but the dark display obviously).

The "TOC writing/blank disc" problem is mostly related to either the OP or the OWH. If your deck plays a loaded disc without skips, that tells the machine is "nearly" fully functional. Whether the OP is dying or the OWH is busted is fairly easy to separate, because you can 1) do a visual check on the OWH, then 2) measure the continuity of the magnetic coil + the yellow ribbon cable of the OWH, when disconnected from the BD board. If all good, the OP is to deal with. But that's a whole lot of a different story then :-) .

[denisten73]

Could it be some scenario like this : https://www.jonathandupre.fr/articles/17-minidisc-md/240-reparation-platine-md-sony-mds-j3000-japonaise/ ?

[NGY]

3 hours ago, denisten73 said:

Could it be some scenario like this : https://www.jonathandupre.fr/articles/17-minidisc-md/240-reparation-platine-md-sony-mds-j3000-japonaise/ ?

Can you be a bit more specific? What is the "it" you're referring to? The TOC writing problem, or the dark display, or else?

Sadly I don't speak French at all. From what I see on the pictures, Jonathan dealt with a faulty power regulator IC, and the symptoms in his case - if I got it right - don't seem to have much similarities with your case (either the dark display, or the TOC writing problem, the latter being 99,99% sure as not a regulator issue).

Honestly, my limited knowledge already ended with the conclusion above, and - if your 510 was in front of me - taking that repair attempt any further I could/would only rely on swapping the boards with known good parts, to see if something pops out - either to support the conclusion, or to discover something totally different I possibly overlooked.

[denisten73]

10 hours ago, NGY said:

Honestly, my limited knowledge already ended with the conclusion above, and - if your 510 was in front of me - taking that repair attempt any further I could/would only rely on swapping the boards with known good parts, to see if something pops out - either to support the conclusion, or to discover something totally different I possibly overlooked

I meant the dark display.

This deck is probably going for parts.Thank you for your help and patience. I really appreciate it a lot.

[NGY]

Well, we tried it at least. It needed more patience from your end, and you did a good job in getting back with exact measures, etc. Many people just don't bother coming back and telling what happened, while any information, even dead-ends could help future readers.

Back to Jonathan's post for a second: I took a grab on the text with an on-line translator, and what I understood is that his J3000 did not want to turn on, some segments on the VFD lit briefly, but the machine did not do anything beyond. He found the reason was IC309 being faulty, with the 3.3V system rail being shorted to ground internally.

I feel pretty much convinced - as your 510 does have the necessary power rail voltages and lot of functions (turning on and off, disc loading, etc., etc.) do work - that your's is a different case. Nevertheless, you may want to close that thread too for peace of mind, and measure the voltages on that regulator (as well as checking the one in your 510 if it shows that overheating symptom too). Some of it's signals are sensed by the MCU, it may worth a few minutes to see if all is there.

[denisten73]

I will check that regulator and then remove the battery at the weekend and that will be the end of that thread. Thanks once again, i did a gret job because of you.

[denisten73]

Regulator checked - all voltages are present, battery removed - no difference. This deck is going for parts. Many many thanks NGY.