Sony MDS JB980 stuck on standby mode

[sfbp]

Interesting! So that configuration generates an invitation to flash the EEPROM......

No, sorry, not about to open my unit up to see if that is normal. But I wonder if the Service Manual talks about it.

[kgallen]

According to the schematic, the long ribbon doesn't carry any power (there is one D-GND). It seems to have most of the "low activity" signals like switches and the EEPROM. All of the power comes in on the smaller ribbon plus many of the servo signals. Plenty of GNDs on the narrow ribbon with those fast signals which is what you need...

[kgallen]

5 minutes ago, sfbp said:

Interesting! So that configuration generates an invitation to flash the EEPROM......

No, sorry, not about to open my unit up to see if that is normal. But I wonder if the Service Manual talks about it.

Sort of, but it can't do it. Whilst the EEPROM SDA/SCL (I2C/IIC) signals are on the wide ribbon there is no power. So the CPU can't read the EEPROM, but similarly without the narrow ribbon inserted there is no power to write the EEPROM.

But please don't try it, input clamping diodes on chips can sometimes provide enough power via the input signals to operate the chip marginally (as an aside, that's apparently how the ARM CPU was accidentally discovered to be a "low power" design - they forgot to wire up the power pins, but the first chips still "operated" through the current available through the input diodes from sufficient input signals at "logic high".).

 

[sfbp]

Petter you mentioned the jumper - the one which resets the microprocessor. I presume that's back and making firm contact?

My other thought was maybe to press the NetMD button. There are endless warnings in these units about the chip (IC195 in this case) being one-of-a-kind because it serialises the machine for the purposes of copy protection. You literally CANNOT change that IC with a new part. Is that the EEP referred to?

[kgallen]

5 minutes ago, sfbp said:

Is that the EEP referred to?

I'm pretty sure that message refers to the EEPROM on the drive with the laser diode characteristics.

The part for DRM would be more like a fixed MAC address I suspect.

[Petter Halonen]

3 minutes ago, sfbp said:

Petter you mentioned the jumper - the one which resets the microprocessor. I presume that's back and making firm contact?

My other thought was maybe to press the NetMD button. There are endless warnings in these units about the chip (IC195 in this case) being one-of-a-kind because it serialises the machine for the purposes of copy protection. You literally CANNOT change that IC with a new part. Is that the EEP referred to?

The jumper is back . The NetMD button does not do anything.

[kgallen]

15 minutes ago, sfbp said:

There are endless warnings in these units about the chip (IC195 in this case) being one-of-a-kind because it serialises the machine for the purposes of copy protection. You literally CANNOT change that IC with a new part. Is that the EEP referred to?

Stephen you're right:

[sfbp]

So that's evidence of a sort of the kind you were looking for that the mainboard is/is not recognising the drive (BD), in this case because the second cable is not connected? I wonder if that means the cables. It's almost as if the jumper never got replaced (yes, Petter, I know you did replace it - but not sure why you took it off!?). Or maybe some other initialization that has to be done after you've reset the CPU?

[Petter Halonen]

7 minutes ago, sfbp said:

So that's evidence of a sort of the kind you were looking for that the mainboard is/is not recognising the drive (BD), in this case because the second cable is not connected? I wonder if that means the cables. It's almost as if the jumper never got replaced (yes, Petter, I know you did replace it - but not sure why you took it off!?).

I took it of because, I read someone had fixed a problem like mine that way. The took of teh jumper waited a few second and put it back, then when they put the main socket in the MD-player was ok.

I mesured the battery it is 2.8V, so maby litle low? It shuld be 3,2V?

[sfbp]

The CR2032? Don't know...

When you got that message "Init EEP?" what did you do? I hope you pressed MENU/NO. If you didn't but simply turned it off, I want to know what happens when you press MENU/NO.

 

[Petter Halonen]

1 minute ago, sfbp said:

The CR2032? Don't know...

When you got that message "Init EEP?" what did you do? I hope you pressed MENU/NO. If you didn't but simply turned it off, I want to know what happens when you press MENU/NO.

 

Nothing happend when I pressed MUNEU/NO ,so I took out the power. I put the robon back and everything is like before. I don't think I damaged anything.

[sfbp]

That's fine, I think. It looks like we now know the procedure for setting the GUID in the EPROM, at least the start of it. Thanks!

Was the machine powered/standby/unplugged when you took off the jumper and put it back on?

[Petter Halonen]

Just now, sfbp said:

That's fine, I think. It looks like we now know the procedure for setting the GUID in the EPROM, at least the start of it. Thanks!

Was the machine powered/standby/unplugged when you took off the jumper and put it back on?

The machine was unplugged.

[sfbp]

So that's why I was wondering about the NetMD button. If the USB is playing up then maybe the microprocessor gets stuck. So to be clear, I think NetMD needs to be OFF at all times until you are ready to (maybe) reprogram the EEPROM (assuming there is a problem there which is not particularly likely).

[Petter Halonen]

2 minutes ago, sfbp said:

So that's why I was wondering about the NetMD button. If the USB is playing up then maybe the microprocessor gets stuck.

So how do you want me to test that? 

[sfbp]

Maybe you think I know a lot. I don't - only asking dumb questions in the hope that you or Kevin, both of whom actually KNOW something and can act on it.

Have you made sure there's nothing messing up the USB circuits? Nothing plugged in and no shorts. Then it might be interesting to see whether, with the USB plugged in and connected to a PC, whether pressing the NetMD button does anything? That would indicate, perhaps, that the machine is (sort of) alive. Kevin?

[Petter Halonen]

Just now, sfbp said:

Maybe you think I know a lot. I don't - only asking dumb questions in the hope that you or Kevin, both of whom actually KNOW something and can act on it.

Have you made sure there's nothing messing up the USB circuits? Nothing plugged in and no shorts. Then it might be interesting to see whether, with the USB plugged in and connected to a PC, whether pressing the NetMD button does anything? That would indicate, perhaps, that the machine is (sort of) alive. Kevin?

I did try that. nothing happend. sorry

[kgallen]

I think we’re looking at a simple (ha ha ha) drive issue. USB is probably off track - but of course any ideas are good even to just stimulate thoughts and keep us talking.

No bright ideas from me at the moment. Might pull my 480 out of the shed later and pull it about a bit - it’s a cost reduced version of your 980. 

Kevin

(Stephen has too much faith in us and not enough on his own worthy suggestions)

[Petter Halonen]

Can you read anything out from this video? It is in testmode. there are some numbers saying ok and other saying NG...

[sfbp]

Tell us how you got that? Was it the error history perhaps? (Sorry if you recorded some words, I don't have sound where I am at the moment). Those look to me like tracks (TOC entries). Didn't the disk have 12 tracks on it? Never mind I see the disk had 19 tracks if the same one. But it's using the display which normally shows track numbers and the ones on the display that are highlighted are the ones which say OK in the display as it cycles through.

On the other hand if it's the error history, then these are errors - but that doesn't make sense because errors would be random and not in sequence. These clearly follow a pattern (increasing by 1 and then wrapping around)

[kgallen]

(Stephen there is no narration on the video).

I looked in the 980 and 480 SMs and can find no details of what is in the INFORMATION (C31) section. I'll look in some more...

Is the drive fully back in the machine?

Can you do:

C18 (VERIFYMODE) -> will check the EEPROM

C29 (Iop Read)

C34 (CPLAY1MODE) can you use [YES] to move the sled MID/OUT/IN (the numbers on the display are useful here if anything useful happens) -> Need a recorded disc in for this one.

Actually in CHECK mode you can do C12 thru C27. I'm not sure it tells us much but getting "OK" values back would be comforting!

Admittedly there is not much above that gets us much further than what we think we already know. Just scratching around in the dirt for clues...

Note: There are no warnings in the 480 SM regards IC195 as there are in the 980 SM. So as Stephen suggests, there must be a DRM code included in there for the NetMD machines - 480 is not NetMD.

[kgallen]

Just looking at the SM block diagram, it dawned on me that the loading motor is completely unrelated to the remaining disc mechanisms (laser, servo, audio path). It's driven directly from the main PCB CPU (even the motor drive chip is on the main PCB). It's two pins on the large ribbon cable (LD-OUT/LD-IN, pins 26/27). There will be the loading switch contacts too (OUT-SW, pin 16, goes logic low when no disc in - remember playing with this on my MDS-E10). But even if the rest of the drive was unresponsive, that's the sort of thing that could still work. But I think at this point it's not? Of course if the CPU has not managed to successfully talk to the BD then it will probably refuse to do anything with it.

[sfbp]

Wait a second - this display of information, and the prompt we saw (Init EEP?) are surely indicators that the CPU is alive. Just not talking to the BD. Cables, again.

[kgallen]

12 minutes ago, sfbp said:

Wait a second - this display of information, and the prompt we saw (Init EEP?) are surely indicators that the CPU is alive. Just not talking to the BD. Cables, again.

Yes, the CPU is alive and well. Just not talking to the BD :-D

Sorry, maybe I should have said...!

By the way, if you're trying to find the CPU and it's related infrastructure, you can't see it. Most of it is on the underside of the main PCB. The only stuff on the top is the connectors (internal and external), the power supply (top left), the coax/optical SPDIF drivers and the analogue audio output stage (top right) - with a smattering of (Nichicon?) gold caps I see from the photos...

(The little green daughterboard top centre is the USB -add-on for NetMD. Sony seem to call this chip, CXD1873R, the Unicorn...)

[Petter Halonen]

2 hours ago, kgallen said:

(Stephen there is no narration on the video).

I looked in the 980 and 480 SMs and can find no details of what is in the INFORMATION (C31) section. I'll look in some more...

Is the drive fully back in the machine?

Can you do:

C18 (VERIFYMODE) -> will check the EEPROM

C29 (Iop Read)

C34 (CPLAY1MODE) can you use [YES] to move the sled MID/OUT/IN (the numbers on the display are useful here if anything useful happens) -> Need a recorded disc in for this one.

Actually in CHECK mode you can do C12 thru C27. I'm not sure it tells us much but getting "OK" values back would be comforting!

Admittedly there is not much above that gets us much further than what we think we already know. Just scratching around in the dirt for clues...

Note: There are no warnings in the 480 SM regards IC195 as there are in the 980 SM. So as Stephen suggests, there must be a DRM code included in there for the NetMD machines - 480 is not NetMD.

C18: evything ok

C29: can't get to it jumps from C27 toC31

IopRead isC26 : 56.4/55.7

C34 : it load the disk but does not spinn up or run the sled.

 

[kgallen]

Sorry C29 my typo, should have been C26. I'm looking at p20 of the Service Manual if you have it all (see link at the bottom).

But actually your report is quite comforting, we're getting somewhere. At least the CPU can read the EEPROM properly. You can load (and presumably eject) a disc - is this progress from where we started? Does this mean you can get out of Standby in normal operation, or was your disc load in Service Mode. Even loading in Service Mode gives us some info. Can you confirm if the disc load eject was in Service Mode or normal mode, and if normal if you are able to exit and enter Standby now?

Can you go back to C12 and step through to C26 and report if the results were OK or NG (no good). You can summarise the exceptions rather than write them all out.

Baby steps but it feels like we have a little data to work with.

I'm with Stephen though, I'm still thinking cables. I've just not put my finger on where and how yet...

If you happen to have some isopropyl alcohol (and some cotton buds/Q-tips), maybe you could clean the contacts on the FFC (ribbon cables) at both ends and in the sockets on the PCBs. Let them dry a few minutes before reassembling.

MDS-JB980 Service Manual

[Petter Halonen]

 The disc load was in Service Mode, no respons to eject. I can exit sevicemode and enter standby.

They look ok to me, only the disk does not spinn up.

I'm thinking maby something wrong whit IC201 or the riboncable,  the signal from cpu to BD on pin 15 IC201 ?

It is geting late here, Tomorrow I wil clean the riboncables and get my osciloscope to se if there are any signal on ic201 pin 34 and 35.

Thank you for helping me

Petter

[kgallen]

Agree Petter, getting late here too. I'll look up your IC201 then I'm probably done for today too. Good perseverance, have a good night!

Kevin

ETA: Oh, IC201 is the main chip (DSP), the CXD2664R. It's possible it's bust (like any other component) but I'm not there with that one yet - game over for the drive if it is (although as we've discussed on other posts, it's not fully game over if you can do without the NetMD section, as a drive from a cheap eBay 480 can get you a replacement MDM-7S1A). Not sure why you've picked on IC201 pin 15 (WRPWR). What's your thinking there? Also I'd say IC201 pins 33/34 is a bit ambitious at this point. They are the PCM connection to the D/A converter. We're not looking for an audio stream problem, we can't detect the disc and read the preamble and the TOC yet, so the audio data is a way off if we end up that deep in the mire... For my money if you're getting the 'scope out, we're looking at some control issue on the signals of the wide ribbon cable. However I don't think we have much in the way of reference material to know what to expect. The narrow ribbon cable looks more audio-side to me (see the block diagram on p39, upper right has the IC201 pins you're talking about and that is all DAC and ADC) and I don't see that we're in audio territory with this problem.

[M1JWR]

i had similar problem with that 940 the other month, i could access service mode but nothing else apart from standby light only.

cant really remember how i got out of it, but it did come out of it, diddent see any refrence to removing ribbons at drive itself and re inserting them.

thats all i ever did with any player, discovered by accident bye the way, i know at some point that woke things up a bit, i always understood that when a

md deck wont come out of standby is when there is either a disc stuck inside or it thinks a disc is stuck inside.

if i remember i will post back on it.

[Petter Halonen]

Update: I have now used my Osciloscope and mesured different clock signal on the BD board.  ic201: pin20 (OSCO) ok, pin34(LRCK) ok, pin35 (XBCK) also ok.

So the servoprosessor get voltage and clk signal. In my head, an ic that get voltage and clk shuld give somting out, or it is toast and need to be replaced. 

I can get a ned IC on net but it is quite expensive, alternativly I can find a spare md-player whit another fault and take the prosessor from that one. 

 

 

[kgallen]

Petter we're not at the stage yet. These are complex chips you can't simply say "stuff in will give stuff out". You don't know which chip, if any, is at fault - the level of fault finding we've done so far is nothing. Even if you could get a genuine replacement CXD2664R, unless you have a whole surface mount repair station how are you going to swap the chip without wrecking the whole board? It is not a trivial operation like replacing a socketed 8-DIP. Maybe you do have this, but there is no fault finding yet that says the DSP is bust. Why would it be unless you were very careless with static electricity precautions when you changed a belt that is on the other side of the mechanism. As an apparently knowledgeable repair tech, I'd expect you to have taken anti-static precautions during the repair. So there is no tangible reason I know of that any of the chips, or the laser, should be damaged.

You've 'scoped and seen activity on the audio DAC/ADC clocks going in an out. That is good in itself but it tells us nothing about the servo side of the chip.

The machine worked prior to the belt change. Look for simple problems. Conclude the main DSP chip is bad when all other simple possibilities are ruled out and based on evidence that it's not responding as it should.

Sorry if that came across as a lecture, I didn't mean it to, but we can approach this in a structured way, especially given your quoted experience.

[Petter Halonen]

Thank you! You are right. I shuld not make it more complex than it is.

 I know that the main controler is ok. In Check mode C35, the over write head goes down when I puch yes and up when I push no.

[kgallen]

Maybe next step to rule out damage is to extract the drive and do a careful and systematic inspection of it. Mechanical and electrical. If you have an illuminated inspection lens then all the better. Overall we’re looking for things that ‘don’t look quite right’ as we have no reference. Mechanically we’re looking for misplaced components, broken plastic or gears. On the electronics we’re looking for surface scrapes as clues, cracks in components especially small surface mount capacitors and resistors, solder joints that look stressed and PCB traces that look cracked or heaven forbit pads lifted. Looking especially around those ribbon cable connectors and areas that might be stressed. Look for shorts or bits of dirt or flakes of metal picked up from your desk. 

If we find nothing that is good but it’s a step we need to take to rule out issues.

If you have your ‘scope, by all means use it. There are reference waveforms in the SM but whether or not any will be active if the drive can’t initialise we can’t say. But we can scope out each of the switches on the BD like limit-in and out-sw and ensure we get a logic low and high. These can be probed at the main PCB end of the ribbon cables.

If you have a 2-channel scope then you can check the I2C (SCL and SDA) for appropriate activity. Again no reference for us and we don’t know what data the bus is carrying but we can look for START and STOP conditions and transitioning data bits. Here is the I2C spec if you don’t know how START and STOP are signalled on SCL/SDA. However I still think we’re looking for something more fundamental so I recommend the thorough inspection before any of that.

Also vitally important are simple observations like Stephen’s idea on the Timer switch. Crazy to pull a good machine to bits only to find we had something set wrong. So if you haven’t, spend a few minutes looking around the machine in general for clues and ideas. 

The observation on the OWH is just the thing we’re looking for. Simple responses can indicate a lot of the circuit is working. In my job, just getting an LED lit or being able to read a chip register mean a lot of stuff is working. It's quite likely the instructions for the OWH came over the I2C from the main CPU to the BD board, so looking at the I2C for a "catastrophic fault" is probably redundant.

Kevin

NXP I2C Specification

Look at section $3.1.1 onwards.

[Petter Halonen]

update: There is trafic on I2C line ( SDA, SCL).  I have cleaned the riboncabels and inspected them. They seem to be ok. Next thing is to once again have a look at the mecanic, and see if the switches are in the correct potition.

Later I will have a friend over to have a look , new eyes culd see something I don't see....

[kgallen]

Good news! I think there are 3 switches - WP, REFL, LIMIT and OUT. All of these should be probe-able on the ribbon cable at the main PCB end for convenience. All are resistively pulled up to 3.3V and when the contacts are closed are shorted to 0V.

WP and REFL are tiny blue/white pins that detect holes/depressions in the MD disc case.

LIMIT and OUT are part of the drive mechanism, but are harder to get at as they are burried between the drive PCB and the mechanics. However given that in SM you can insert a disc, the OUT should be able to toggle. If you can move the sled in SM then LIMIT should be able to toggle (disc outer edge limit I think).

Frustrating we still can't nail this.

Did you do any visual inspection?

[Petter Halonen]

Yes I did. the first thing I do when searching for fault is visual inspection, and the sniftest... in cace somthing is burned. Only thing I noticed was the erea around Q203 was a bit brown. Tured out to be harpics. 

 

[Petter Halonen]

On 5/15/2020 at 12:40 PM, kgallen said:

Good news! I think there are 3 switches - WP, REFL, LIMIT and OUT. All of these should be probe-able on the ribbon cable at the main PCB end for convenience. All are resistively pulled up to 3.3V and when the contacts are closed are shorted to 0V.

WP and REFL are tiny blue/white pins that detect holes/depressions in the MD disc case.

LIMIT and OUT are part of the drive mechanism, but are harder to get at as they are burried between the drive PCB and the mechanics. However given that in SM you can insert a disc, the OUT should be able to toggle. If you can move the sled in SM then LIMIT should be able to toggle (disc outer edge limit I think).

Frustrating we still can't nail this.

Did you do any visual inspection?

I mesured the different switches with the disc inside.

 Limit I managed to get to togle between 0 and 3.3V, by turning the gear so the sled went out /in. so that is ok. 

Out and REFL was 3,3V , WP and Protect was 0V .

What worries me is WP and OUT.. are they correct? 

I'm puting up a sheet in exel to mesure all the pins on both cn102 and 103 to get an bether overwiew. maby it will get clear to me then.

[kgallen]

19 minutes ago, Petter Halonen said:

 Limit I managed to get to togle between 0 and 3.3V, by turning the gear so the sled went out /in. so that is ok. 

Good.

19 minutes ago, Petter Halonen said:

Out and REFL was 3,3V , WP and Protect was 0V .

With a disc in, WP should show the state of the movable flag that is used to indicate a write protected disc - the little white slider in the corner of the disc case. When writeable (slider covering the hole) then I'd expect WP=0V, when write protected (hole is open) then 3.3V.

REFL is the disc reflectivity. With a recordable MO disc then the REFL hole is open so I'd expect 3.3V. If you have a pressed MD-CD disc then the hole is blocked so expect 0V. The REFL hole is next to the WP hole in the MD disc case.

OUT switch should show (probably) 3.3V with a disc out and 0V with a disc in. (The state should be different with a disc in compared to a disc out.). This is possibly the most interesting one given our issue. The switch is burried so it's hard to see. But having this one change state between disc out and disc inserted is obviously important!

 

 

[Petter Halonen]

OUT switch should show (probably) 3.3V with a disc out and 0V with a disc in. (The state should be different with a disc in compared to a disc out.). This is possibly the most interesting one given our issue. The switch is burried so it's hard to see. But having this one change state between disc out and disc inserted is obviously important!

I ejected the disc manualy an mesured again. out sw is now 0V and the same is refl.

 

[Petter Halonen]

Update: After geting some help from a friend, I think we are on to something.  The CLKA signal from pin 5 on IC803 has an amplitude of only 1 V p-p, so it is only 50% of what it shuld be. Input clock on pin 1 has an amplitude of 2,5 V p-p, so that is correct. the VCC pin 2 and FS1 pin 7 is 3,3 V and pin 4 and pin6 is GND.

So there must be somthing wrong whit IC803 or IC201 making the amplitude go down.