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Thread: Old Technics CD player not reading discs

  1. #1
    Join Date: Apr 2015

    Location: Oxford

    Posts: 195
    I'm Andy.

    Default Old Technics CD player not reading discs

    This is probably a bit specific but maybe there's an old Technics service department person on AoS? I should be so lucky...

    I've been getting into old CD players and ended up with, amongst others, an SL-P350 and SL-P990. Both worked when I got them although both sounded flat and crap, probably due to the capacitors being long past their prime. The 990 used as a transport showed real potential though and I started to use it that way but it quickly developed a fault and would jump on certain discs (classic ebay quality). Long story short I found some sticky stuff on the rails and cleaned that off.

    But before I did that I had a working 350 and believed the transports to be the same so decided to swap them over. It was only when I'd taken them both out that I discovered the 990 has a separate plate on the underside with what appears to be a bank of additional capacitors. As the mechanisms were different I then put them both back into their original players. This is just plug and play stuff, no soldering required. All back as it was, except possibly the screws holding the drives in place not being in the same location, neither player would find the TOC on any disc. I'd succesfully broken both of them!

    The discs spin, I can see a red laser coming out (being careful not to look right at it), the laser sled slides to the centre of the disc and the focusing mechanism goes up and down. Everything seems fine but it never reads the disc. On the 990 I tried playing around with the yellow adjustment pots, spending about an hour at random and then finding the service guide and setting them to factory defaults. On the 350 I haven't touched the pots. On the 350 I also (later) tried wiping the stiff circuit bit (if you've seen inside the players you'll know the bit I mean) with isopropyl alcohol and sprayed all the connections with deoxit before reattaching them.

    No joy. The disc spins and spins but it never brings up the TOC or plays. Anyone seen this before? Have I simply broken two players in identical ways at the same time?

  2. #2
    Join Date: Feb 2013

    Location: W Lothian

    Posts: 99,005
    I'm Grant.

    Default

    Were you wearing a grounding strap? A static discharge could cause it
    Regards,
    Grant .... ؠ ......Don't be such a big girl's blouse

    I've said it before and I'll say it again: democracy simply-doesn't-work
    .... ..... ...... ...... ................... ..... ..... ..... ..... .....
    FIIO K7 BT, M11 PLUS, BTR7, KA5 - OPPO BDP-103D - PANASONIC UB450 - PANASONIC 4K ULTRA HD TV - PIXEL 6 - AVANTREE LR BLUETOOTH - 2* X600 SOUNDCORE - HEADPHONES INCLUDE, FIIO, NURAPHONES', FOCAL, OPPO, BOSE, CAMBRIDGE, BOWER & WILKINS, DEVIALET, MARSHALL, SONY, MITCHELL & JOHNSTON - 2*ZBOOK'S- MERCURY BD ROM, ROON, QOBUZ, TIDAL, PLEX, CYBERLINK, JRIVER - MULTI HDD'S -

    Oh my god! There's nothing wrong with the bidet is there?

    “Nothing discloses real character like the use of power. It is easy for the weak to be gentle. Most people can bear adversity. But if you wish to know what a man really is, give him power. This is the supreme test. It is the glory of Lincoln that, having almost absolute power, he never abused it, except on the side of mercy".

    “You see these dictators on their pedestals, surrounded by the bayonets of their soldiers and the truncheons of their police ... yet in their hearts there is unspoken fear. They are afraid of words and thoughts: words spoken abroad, thoughts stirring at home -- all the more powerful because forbidden -- terrify them. A little mouse of thought appears in the room, and even the mightiest potentates are thrown into panic.”

    "You don't have free will. You have the appearance of free will.”

    “There's a war out there, old friend. A world war. And it's not about who's got the most bullets. It's about who controls the information. What we see and hear, how we work, what we think... it's all about the information!”


    ***SMILE, BE HAPPY***

  3. #3
    Join Date: Apr 2015

    Location: Oxford

    Posts: 195
    I'm Andy.

    Default

    No, sadly not. I've built computers for years without one and never had an issue, but I guess I could have fried something. They're old players so might not be as resilient. The display still works, disc still spins, its just the TOC reading so an odd thing to fry.

  4. #4
    Join Date: Feb 2013

    Location: W Lothian

    Posts: 99,005
    I'm Grant.

    Default

    just a possibility Andy. I usuall have myself attached to something somewhere earth wise. Could be sommat else though
    Regards,
    Grant .... ؠ ......Don't be such a big girl's blouse

    I've said it before and I'll say it again: democracy simply-doesn't-work
    .... ..... ...... ...... ................... ..... ..... ..... ..... .....
    FIIO K7 BT, M11 PLUS, BTR7, KA5 - OPPO BDP-103D - PANASONIC UB450 - PANASONIC 4K ULTRA HD TV - PIXEL 6 - AVANTREE LR BLUETOOTH - 2* X600 SOUNDCORE - HEADPHONES INCLUDE, FIIO, NURAPHONES', FOCAL, OPPO, BOSE, CAMBRIDGE, BOWER & WILKINS, DEVIALET, MARSHALL, SONY, MITCHELL & JOHNSTON - 2*ZBOOK'S- MERCURY BD ROM, ROON, QOBUZ, TIDAL, PLEX, CYBERLINK, JRIVER - MULTI HDD'S -

    Oh my god! There's nothing wrong with the bidet is there?

    “Nothing discloses real character like the use of power. It is easy for the weak to be gentle. Most people can bear adversity. But if you wish to know what a man really is, give him power. This is the supreme test. It is the glory of Lincoln that, having almost absolute power, he never abused it, except on the side of mercy".

    “You see these dictators on their pedestals, surrounded by the bayonets of their soldiers and the truncheons of their police ... yet in their hearts there is unspoken fear. They are afraid of words and thoughts: words spoken abroad, thoughts stirring at home -- all the more powerful because forbidden -- terrify them. A little mouse of thought appears in the room, and even the mightiest potentates are thrown into panic.”

    "You don't have free will. You have the appearance of free will.”

    “There's a war out there, old friend. A world war. And it's not about who's got the most bullets. It's about who controls the information. What we see and hear, how we work, what we think... it's all about the information!”


    ***SMILE, BE HAPPY***

  5. #5
    Join Date: Feb 2011

    Location: England

    Posts: 290
    I'm James.

    Default

    Static damage is a possibility but I've never managed to damage a Laser from a Player of this vintage.
    Modern electronic equipment seems to be much more susceptible to Static jolts. I'm led to believe it is a cost saving exercise by the manufacturers of 'chips' etc, not putting as much protection in modern devices placing the onus on the technicians fitting/replacing them to be fully 'Anti-Static'd up'.

    It is odd that both now display the same symptoms.
    I am going to guess you have checked and double-checked all the ribbon cables and connectors you must have had to un-plug and plug back in. Were there and Flexible PCB Ribbons? I would assume the Laser ribbon was. It may be worth checking this with a magnifier. I have had some of the connectors become detached from the stiff end piece and cause all sorts of problems.

    If you get really stuck I am in Oxford too (well, just outside, Wheatley) and used to work for a Panasonic ASC repairing these things for a living. Perhaps one Sunday you could bring them over and I'll take a look. Maybe not while you wait, it depends how untidy my workshop (shed !!) is

    Send me a PM. I am away this next weekend (I work Saturdays, my weekends are Sundays and Mondays) but I think free after that for a bit.

    Jim.

  6. #6
    Join Date: Aug 2009

    Location: Staffordshire, England

    Posts: 37,779
    I'm Martin.

    Default

    You might have damaged the ribbon connectors. They are quite fragile. I've had that happen. I think you can hardwire them instead, IIRC that is how mine was fixed.
    Current Lash Up:

    TEAC VRDS 701T > Sony TAE1000ESD > Krell KSA50S > JM Labs Focal Electra 926.

  7. #7
    Join Date: Apr 2015

    Location: Oxford

    Posts: 195
    I'm Andy.

    Default

    Quote Originally Posted by JimC View Post
    Static damage is a possibility but I've never managed to damage a Laser from a Player of this vintage.
    Modern electronic equipment seems to be much more susceptible to Static jolts. I'm led to believe it is a cost saving exercise by the manufacturers of 'chips' etc, not putting as much protection in modern devices placing the onus on the technicians fitting/replacing them to be fully 'Anti-Static'd up'.

    It is odd that both now display the same symptoms.
    I am going to guess you have checked and double-checked all the ribbon cables and connectors you must have had to un-plug and plug back in. Were there and Flexible PCB Ribbons? I would assume the Laser ribbon was. It may be worth checking this with a magnifier. I have had some of the connectors become detached from the stiff end piece and cause all sorts of problems.

    If you get really stuck I am in Oxford too (well, just outside, Wheatley) and used to work for a Panasonic ASC repairing these things for a living. Perhaps one Sunday you could bring them over and I'll take a look. Maybe not while you wait, it depends how untidy my workshop (shed !!) is

    Send me a PM. I am away this next weekend (I work Saturdays, my weekends are Sundays and Mondays) but I think free after that for a bit.

    Jim.
    I've taken a couple of photos of the ribbon on the 350 below. They look okay to me, but I'm only at the plug and play level of electronics at the moment. The other wires are two, three and four pin connectors and I think they only go in one way, although maybe I'll try turning them around again.




    If there's nothing obvious there then I may take you up on your very kind offer to look at them (only the 990 matters, you can diissect the 350 and throw it away afterwards if you want). I'll PM you tomorrow if nothing comes to light here.

  8. #8
    Join Date: Apr 2015

    Location: Oxford

    Posts: 195
    I'm Andy.

    Default

    Can I just say a really big thank you to James for getting my 990 working again!

    For those who may find themselves in a similar situation I made two schoolboy errors. The first was after taking the transports out of both machines, reassembling the 990 and then putting the 350 back together I discovered I only had three screws left for the 350. I couldn't find it anywhere so just assumed it must be on the floor somewhere. What actually happened was that the screw had got stuck to a magnet in the 990 transport and was just sat there causing a problem.

    The second issue was that the ribbon cable needs to be routed between two plastic spiggots under the transport. I'd gone round the outside of both and although it appeared to fit it no longer had enough reach to let the laser read the TOC. My error was assuming that because it reached the mainboard it must have been right everywhere else.

    Ah well, you know what they say about assumptions

  9. #9
    Join Date: Feb 2013

    Location: W Lothian

    Posts: 99,005
    I'm Grant.

    Default

    That's good news. Nice one james
    Regards,
    Grant .... ؠ ......Don't be such a big girl's blouse

    I've said it before and I'll say it again: democracy simply-doesn't-work
    .... ..... ...... ...... ................... ..... ..... ..... ..... .....
    FIIO K7 BT, M11 PLUS, BTR7, KA5 - OPPO BDP-103D - PANASONIC UB450 - PANASONIC 4K ULTRA HD TV - PIXEL 6 - AVANTREE LR BLUETOOTH - 2* X600 SOUNDCORE - HEADPHONES INCLUDE, FIIO, NURAPHONES', FOCAL, OPPO, BOSE, CAMBRIDGE, BOWER & WILKINS, DEVIALET, MARSHALL, SONY, MITCHELL & JOHNSTON - 2*ZBOOK'S- MERCURY BD ROM, ROON, QOBUZ, TIDAL, PLEX, CYBERLINK, JRIVER - MULTI HDD'S -

    Oh my god! There's nothing wrong with the bidet is there?

    “Nothing discloses real character like the use of power. It is easy for the weak to be gentle. Most people can bear adversity. But if you wish to know what a man really is, give him power. This is the supreme test. It is the glory of Lincoln that, having almost absolute power, he never abused it, except on the side of mercy".

    “You see these dictators on their pedestals, surrounded by the bayonets of their soldiers and the truncheons of their police ... yet in their hearts there is unspoken fear. They are afraid of words and thoughts: words spoken abroad, thoughts stirring at home -- all the more powerful because forbidden -- terrify them. A little mouse of thought appears in the room, and even the mightiest potentates are thrown into panic.”

    "You don't have free will. You have the appearance of free will.”

    “There's a war out there, old friend. A world war. And it's not about who's got the most bullets. It's about who controls the information. What we see and hear, how we work, what we think... it's all about the information!”


    ***SMILE, BE HAPPY***

  10. #10
    Join Date: Feb 2011

    Location: England

    Posts: 290
    I'm James.

    Default

    My pleasure. Glad it's all working OK. You'll have to let us know how you get on with the 350 !!

    Many thanks for the 'Pride. Very tasty

    James

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