Petter Halonen

The problem is the one described above in this thread. It is the micrcontroller on mainboard. Sony did have the cpu with firmware, but it is now out of stock. I have equipment to change the cpu if I only can get one.

Does anybody know where to buy a new cpu for jbs980? Petter

I have concluded the CPU is toast, so I will try to find a used MD player to replase this one. And I think I will try to find one in ES series whit Atrac Type R or S, Actualy do not think they made ES whith Type S, so it will be Typer R then. Is it correct that the difference between Type R and S is that Type S is net-MD ? Petter Halonen

I got a new OP for the player, but stil no luck. Now the player is dead and only clicks twice when I put in the mainlead. I tried to force the power on, and I can se some strange digits in the display but nothing more. So I think there most be something the CPU detects that is wrong. I have no idea what this culd be. be.🤔🤯😩😩

It was defently not me resoildering them, I also noticed that, and mesured to see if there was any shorting. This pins (20 -25 ) are mostly 3.3V and clk signal or not in use and there were no shorings.

update: I managed to forse the power to say on, by shorting Q911. I used the FLIR cam to see if anythig got more warm than normal, but nothing got warmer than 42C which is normal for voltageregulators. Then I mesured all the voltages and everything is as it shuld be. So I guess this is the MCU that is messing things up because it detect or don't detect somthing.

I tried this, what happens is nothing or leds litt up like last picture randomly. Also tried different buttons to see what happend and it is the same. I have tried to disconect USB-board. Today I have got the Flir-cam so I will try to force the power on and see if anything get warm. I'll keep you updated.

I actually managed to get the standby led to lid now. I mesured on Q755 while I turned on the power, and the LED litt up. But now it is dead again... only when I put it in to servicemode it looks like picture below.

Thank you for the advice. I tried this as soon as I read your advice, but no luck. still goes directly to standby and refuses to take the disc if i try to put in the minidisc.

The problem now is that it switches to standby and I can't even get it in to servicemode. The backup battery is defect, only 0.4V by the way. There is no lite in the standby led. I only have 3.3V system and Back 3.3V. But I will not give up ... The fault is probably very simple thing when I find it. A friend of mine will bring over an Flir camera and we will try to disable the shutdown signal momentarily, just to see if something get to hot.

I mesured it between pin 3 on IC401 and GND, while the mainboard was disconected, so no frontboard, USB bord, BD board or powersupply board. Probably the MCU or leaking cap. does anybody have a player they culd mesure tis to see if it is ok or not?

My MD/player is still dead. I did disconect all the wires and put it aside for a cuple of weeks, but it did not help. Then I took out the mainboard only to discoverr that Sony took a shortcut and did not wash the card after running it trough soilderingbath. So I cleaned it in redspirit and put id to dry up. Now it is clean like it is suposed to be. I mesured the resistanse from different voltages to ground. one of them sticks out. The system 3.3V has only 66 ohm to ground. So I have to digg in to that and find out why. Here some before and after pictures of IC1 (Systemcontroll) There is some dust on across some pins on the afterpicture, I took them away.

Thank you for helping me. I'll start with disconecting everything and wait a cuple of days. I don't think I will put it in wather yet....

HI. I haven't had time to move forward, I tried to put the divice in service mode but it looked like on the picture below. I wil try to find time this week for repairing the player , as I love it very much, and was so proud to have it in my stereo. I have Tandberg amplifiers and cd-player, which maches well to the Sony MD-player.

During my search for the fault it changed from switching on, but no display, to switching on and and then off. So at the moment it switches of the rele and there is only system voltage (3,3V). What happend was that I mesured PDOWN on pin 4 CN3 and sudenly it switched off.

I haven't checked the OP, but I have one brand new, so I can try to check that. The situation now is that the player is stuck i standby. When I put in the main lead I can hear two clicks, so the rele is closed then released. There is 3,3V systempower. Today I borrowed a FLIR camera to see if anything get warm, but nothing was warmer than 24 C. I have a question. If the BD board is disconekted, will there be light in the display?

The display is switched of and the standby LED is litt. but the power is not in standby. The Q911 is on so the rele is swithced on .P. Down pin19 on IC1 is 3,3V. I mesured whit osciloscope and then ther is a puls signal there, almost like it is trying to switch of or on but can't. And that is how far I have got with it. I mesured the P.Down signal whit the scope and sudenly the rele klikked and now it is dead. All I have is the 3.3V system power. Probebly easyer to find the fault now.. I hope.

Wondering if it is something caused by ESD. This is like a gohst kidding whit me. The P down signal is 3,1 V... strange that it is only halfe in standby. mabye I'll have a look at it. I do have one md walkman, but this was my fawourite player of all time. I had just got it talking whit my win10 computer.

I mesured whit another probe on my scope and now the signal is correct, so you were right. My bad... again.. That is why I always have this mistrust to what I mesure and tripel or octcheck what I mesure if the signal look suspitious. Back to start ( almost). man this is frustrating...

1.7V on pin 5 is DC, signal shuld be 2,5Vp-p as I undestand it... mabye I'm wrong again... he he.

acording to service manual, the clock signal from ic803 shuld be 2.5Vp-p, mine is 1Vp-p.

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.

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.

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.

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.