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Petter Halonen

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Posts posted by Petter Halonen

  1. 8 minutes ago, sfbp said:

    What about that first picture? See the 5 pins that have had resoldering done on them - is it possible there's a short there (I see some what-looks-like-guck between the 1st and 2nd and also 2nd and 3rd). I've no idea which pin does what (I leave that to the expert detectives) but my assumptions are:

    1. they are something important
    2. someone worked on them before. Was that you, Petter?

    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.

  2. 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. 

  3. 13 hours ago, NGY said:

    Can you please check one thing, what happens: keep pushing AMS knob and Rec button together while plugging the AC cord. This should work even on a stuck-in-standby device, at least whenever I tried in the past it did work. Normally, it brings up the display/leds/buttons/knobs/remote test sequence.

    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.

  4. 48 minutes ago, NGY said:

    Sad. At least we learned two things: 1) it is not the IR receiver chip and 2) it is not the VFD driver chip that keeps the deck in standby. We must look then elsewhere.

    I would turn to the OP now, but the fact you cannot enter Service mode is worrying me. You cannot really destroy your spare OP even with the settings for the present one, as long as you don't activate the higher laser power (recording), but it would be better to reset all settings in the setup menu prior to the OP exchange, then readjust everything step by step.

    Giving a chance to replacing the OP might bring your Service mode back, and if it does, it probably solves the main issue too. Cross our fingers. Just don't try anything else with the new OP except trying to switch the unit on. If success, we go from there.

    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.

    servicemode.jpg

  5. 1 hour ago, NGY said:

    The standby led not lit regardless you have the 3.3 Volts is strange at least. It is switched by the VFD driver chip (and supplied directly from the system 3.3V, the output of IC401).

    Do you probably have a display chip issue?

    To check this, you can try to disconnect the display section from the front panel board, together with the switches/IR/leds section - keep only the switches/encoder section connected via the ribbon cable to the main board. Plug the AC cord, and listen to the relay clicks. Hopefully you hear two. Then insert a disc to see if the deck loads it in, and if the disc spins. If it does, you can eject it with the eject button (or, actually, you can try pushing the Play button too).

    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.

  6. 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.

  7. 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.

    MDS-JB980_IC1 before.jpg

    MDS-JB980_IC1 after.jpg

  8. 9 minutes ago, NGY said:

    Hi Petter, I am glad to hear about you again, although it is a bit worrying that you cannot enter Service mode now.

    You may want to disconnect all cables inside the deck, so all individual panels stand on their own and not connected to each other by any way. Then, after removing the reset jumper, leave your deck with all cables and jumper removed for at least two-three days, before you will again have time to continue the repair.

    There is another trick that I have been using back in the ancient times of first IBM XT/AT PC-s, but I just do not dare to recommend it for such a delicate machine. When we faced a computer being dead or irresponsive, had tried everything but nothing helped, we finally stripped it down to its individal cards, and put the cards into buckets full of clean water for 24 hours. In many cases, this "barbarian-like" treatment helped, the water discharged any hidden potentials in caps, IC-s, or between other components.

    Now, I am not saying this is what you should do with your precious 980. But one of the main chips seems playing a game with you, that can also reasonably be some stubborn static charge (hopefully not yet an irreversible ESD damage) somewhere inside the silicon. A "lighter" version of the above trick we used on fine electronic measuring instruments for the same purpose was shorting the leads (talking about old through-hole components) of the ICS with thin copper wires, or, we simply covered the leads with aluminium foil, using a small brush (this also worked on SMD components later). If you decide go this way, it is important to re-emphasize the necessary appropriate ESD protection measures.

    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.... 

  9. 14 hours ago, NGY said:

    I would love to hear back from Petter, whether or not he had time to move forward with his repair.

    We all learn from these cases, and I am personally very interested, because I had a couple of very similar problems in the past, that I could never properly solve. And I also wish he was finally able to get his 980 back to life, as it is a valuable machine.

    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.

    MDS-JB980_Servicemode_error.jpg

  10. 58 minutes ago, NGY said:

    I went thru the whole thread again, and I am sorry, I overlooked this:

    But as I also read this:

    What is the better describing?

    If plugging the AC cord in, you get all power rails on and valid values, no reason to tinker with the "911" circuit. In that case, checking the "cleanness" of the DC rails might make sense, and peace of mind regarding the PSU.

    If plugging the AC cord you get only the 5V for the relay (* as above) and the system 3.3 V (**), then my previous post may apply.

    (** pin 3 of IC401)

    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. 

  11. 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? 

  12. 46 minutes ago, kgallen said:

    Explain to me again where we are with the Standby condition...

    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.

  13. 18 minutes ago, kgallen said:

    Don't necessarily agree. That chip supports a directly connected crystal across the XIN/XOUT pins. The crystal is excited by a lower amplitude sine wave than the usual digital levels. In this application they haven't used a directly-connected crystal, they are sourcing the clock from elsewhere. The clock they have sourced is probably a full-swing digital signal, and they don't want this for XIN so they've ac coupled it with capacitor C899.

    -> I suspect this is as intended.

    acording to service manual, the clock signal from ic803 shuld be 2.5Vp-p, mine is 1Vp-p.MDS-JB980_signal.thumb.jpg.fe36be1afdc6ff76e2dc38d7414dd5ec.jpg

  14. 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.

     

    MDS-JB980_ic803scema.jpg

    MDS-JB980_ic803.jpg

    MDS-JB980_ic803p5.jpg

    MDS-JB980_ic803p1.jpg

  15. 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.

     

  16. 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.

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