The All Aussie Sega CD Model 1 Repair Adventure

Discussion in 'Repair, Restoration, Conservation and Preservation' started by Brad_83, Aug 3, 2016.

  1. beharius

    beharius Resolute Member

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    OK, got it, Thanks a lot for the info, I was hopeless for that model ...
    I once had a pal Mega CD with a JVC drive, very regretful for selling, seemed more durable to me.
     
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  2. Brad_83

    Brad_83 Blast Power Away!!!!

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    Not a problem, I can understand how you feel about selling it, especially with how rarer they are becoming now. I do believe I also read that the JVC lasers were more durable than the Sony....
     
  3. Brad_83

    Brad_83 Blast Power Away!!!!

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    Issue 5

    Replace internal battery

    https://www.aliexpress.com/item/Fre...-lithium-battery-button-cell/32697080641.html

    http://www.ebay.com.au/itm/10-of-Ba...514797?hash=item4d42854fed:g:0mUAAOSwo0JWLMDI


    20160830_092828.jpg

    Old battery removed by following this instructional video by Global Garage:



    20160830_202926.jpg


    During the removal, two solder pads on the replacement smd caps have lifted off. However, the unit is still booting up, playing audio, etc.

    20160830_092522.jpg


    After speaking to numerous people, I have come to two conclusions.

    1 - Leave it as it is. The smd are only ripple caps and are only used to smooth out the dc current and may not be necessary for the unit to function. There also appears to be another capacitor underneath the board running in parallel, so at least some smoothing is going on.

    2 - Run a wire from the capacitor to the trace on the board to complete the capacitor connection.

    If anyone has anymore input on this matter, that would be greatly appreciated.

    I will update this thread later tonight when I install the battery holder.
     
    Last edited: Oct 15, 2016
  4. Poorcomputerman

    Poorcomputerman Active Member

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    I had my Sega Cd board recapped and now it only plays audio cds and not games. Any idea where I could look on the board?
     
  5. Shane McRetro

    Shane McRetro Blast Processed Since 199X

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    I'd opt for option 2 - Run some kynar to bridge the gaps. Sega wouldn't have put them there unless they were needed - maybe... I guess this was the same Sega that invented Amy Rose... and... Big... o_O
     
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  6. Brad_83

    Brad_83 Blast Power Away!!!!

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    Hey Poorcomputerman,

    I would guess that caps would be the issue as this is the only change that occurred.
    I would make sure all the new caps have the correct polarity, no pads have lifted and that all the correct caps were used. I would only check this on the motherboard. I can't say that I have heard of this issue before but as an audio cd works, I would not expect the laser to be the issue nor the bios.
    This is however only my best guess.

    Good luck
     
    Last edited: Aug 30, 2016
  7. Brad_83

    Brad_83 Blast Power Away!!!!

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    Received the new part today, the worm screw is a different design, it looks a lot stronger so it must be a revised version. I am very happy with the build quality, it looks and feels legit and for $17 USD shipped I'm not complaining. I will install it tonight, replace the belt and see what happens. There is also a metal plate preventing the tray from lifting all the way out. When I get a chance, I will get a 3D scan of the part so anyone with a 3D printer can print one themselves.

    20160905_120906.jpg

    20160905_120943.jpg

    It Worked! The drive raises and lowers as it should now. No more horrible grinding noises!
    The entire drive was replaced, except for the sled, the plastic which the drive motherboard screws into, was too large so I had to use the original. Also, to remove the front of the CD tray, you just need to gently lift up and the face plate will come off.

    All that is left to do is to replace the laser and fix the broken caps on the motherboard and hopefully that should be it.
     
    Last edited: Sep 7, 2016
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  8. Shane McRetro

    Shane McRetro Blast Processed Since 199X

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    Following in your footsteps here! :)
    My drive also doesn't raise or lower properly :D
    The fun is in the challenge! Thank you!
     
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  9. Brad_83

    Brad_83 Blast Power Away!!!!

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    Issue 6

    Disc not reading.

    After fixing the CD tray issue, the next problem is that the CD's are not being read. The laser is recognising a CD is present and will spin the disc, but it doesn't read the TOC. The pots on the laser have been altered due to the plastic/paint not lining up and I have tried to fix it but I think there are too many variables. I have tried a clone laser, but it does't work and I am unable to adjust the power pot on the far right due to no resistance on the pot (there is also no anti-static blob for a KSS-240a so that can't be the issue) I have ordered a genuine laser from http://www.laserlands.net/sanyo-cd-optical-laser-lens-kss-240a-laser-pickup-brand-new.html. They have assured me it is original, watch this space......

    Have just received the new laser and it's genuine. Will install tonight with an update fingers crossed the finish line is in sight...

    20160913_120526.jpg

    Replaced the new laser, the disc will spin, try and read the disc but not detect anything. To rule out the laser, I installed the new laser into my model 2 (which also uses the same laser) and it worked.

    So:
    CD is detected
    Disc will spin
    Laser will reposition itself
    Will make a weird noise as it tries to read, kinda like a low pitched screeching noise
    Tell me to insert disc

    The laser is not the issue

    Darren has suggested that I try and adjust the spindle height, after working on this for a couple of hours I can say that I don't think that is the issue.

    So a recap and a trace check are next on my list
     
    Last edited: Sep 17, 2016
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  10. omp

    omp Familiar Face

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    Good stuff matey!

    Hope you get the ol' beast going.
     
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  11. Brad_83

    Brad_83 Blast Power Away!!!!

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    Hi Everyone,

    I thought I would ask for some feedback about this project so far.

    With the only real issue now being the laser not reading the disc properly and knowing that the laser is working, does anyone else think it could be caps? I starting to run out of ideas and my thought process is that if the caps are not giving off enough charge then perhaps the laser isn't working correctly and doesn't have enough power to function? Are laser very sensitive to currents? I am pretty certain there are no other faults as the system boots up fine with music, tray opening and closing, disc spinning etc.

    If anyone has any other suggestions or ideas I would be grateful to hear them
     
  12. l_oliveira

    l_oliveira Officer at Arms

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    My suggestion is you try your unit with the whole drive assembly from another unit. Then try the optical pickup you just bought on the another unit.

    That way you can figure out if your optical pickup is "DOA". It happens.
     
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  13. Brad_83

    Brad_83 Blast Power Away!!!!

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    Thank you
     
  14. Brad_83

    Brad_83 Blast Power Away!!!!

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    20160917_214923.jpg Can someone please check the power/audio board on their model 1? I have found 2 pins joined by solder on IC2?

    Before I remove it, I just want to make sure it's not done by SEGA
     
  15. Shane McRetro

    Shane McRetro Blast Processed Since 199X

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    Late night Saturday Mega-CD-ing? I love it! :)
    Confirmed as joined on pins 17 and 18 two different units I've previously pulled apart.

    IMG_5294.JPG IMG_5133.JPG
     
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  16. Brad_83

    Brad_83 Blast Power Away!!!!

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    Absolutely Shane! Doing some cleaning and trace checking, very therapeutic! Thank you for your help!
     
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  17. Shane McRetro

    Shane McRetro Blast Processed Since 199X

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    My plastic CD tray / mechanism turned up the other day, I'm hoping it will go well in my Mega-CD - then I need a whole heap of capacitors... how fun :) Thanks for your help in helping me! Keep up the good help... I mean work! :D
     
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  18. Brad_83

    Brad_83 Blast Power Away!!!!

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    Great news on the new CD Mech, I hope it fixes your Mega-CD. Likewise in regards to your help too!
     
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  19. l_oliveira

    l_oliveira Officer at Arms

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    That short is a fix for a circuit errata. Originally they wanted to have a separated audio GND rail but it didn't go well and they converted it to use a single GND rail. Export units also have a patch wire (green or blue I believe) on the under side of the board which connects something on the middle of the power board to the GND pads on the RCA jacks
     
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  20. Shane McRetro

    Shane McRetro Blast Processed Since 199X

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    Sega sure likes having errata everywhere don't they? :) Also how on earth do you have all this knowledge? It's great to hear about all the oddities! :D
     
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