PROGRESS on CD-ROM² Repair

[wolfman]

Recently I acquired a Cdrom that was marked as "non-working". After I relubed the rails it played the first 2 tracks fine. Then it went out and didn´t start again (original middle gear broke into two). I got chops replacement gear from Fidde_se and then it played again, though only roughly 3/4 of an Audio CD.

So I decided to replace all the caps after reading about the whole procedure and tried myself with adjusting it. I am 80% trough this whole thing, only caps I left over are where all the cables are below the switches (they´re tiny and there´s hardly space for my fingers, so I left them where they are). Now all I get is a sound from the sled, which is checking its starting position, and then theres silence. No matter which pots I adjust or which position they have, just nothing.

I must say that I did very thorough reading on the whole re-aligning and re-capping procedure.

What did I do wrong? Any opinions? I appreciate any help!

[Keith Courage]

Hmm, I haven't had that problem before but maybe check that you didn't accidentally install two polarized 10UF caps where non-polarized ones should be used. Also, take a good look at the solder points for the capacitors on the board. I've seen a few pads that can lift up requiring a new lead to be soldered to it.

[wolfman]

Hmm, I haven't had that problem before but maybe check that you didn't accidentally install two polarized 10UF caps where non-polarized ones should be used. Also, take a good look at the solder points for the capacitors on the board. I've seen a few pads that can lift up requiring a new lead to be soldered to it.

No, I definitely didn´t take the bipolar ones out, cause I didn´t have replacement for them.
I can send you a photo of my soldering...looks very clean. But maybe you´ll see something, that I havent seen. I am professionally blinkered by now....

[wolfman]

Also, take a good look at the solder points for the capacitors on the board. I've seen a few pads that can lift up requiring a new lead to be soldered to it.

Hey, I have uploaded 2 pics of the underside of the board. Do you want to take a look at it? Maybe you see something I don´t.

http://www.flickr.com/photos/65709578@N06/sets/72157640174676445/

[Fidde_se]

If tricking the sled door, does the laser light up? any cracks in the pots plastic case?

I'v heard that when trimming the pots to far (certain pots) out of their position can burn the laser for good, that definitely goes for the pot on the laser, which should not be tweaked unless the laser is on it's last toes and need just some extra juice to crack it up.

And sometimes when adjusting the pots just the slightest, either by ear or by measuring it can make it go from read bad to not at all, when it stops spinning you know it's to far.

[wolfman]

If tricking the sled door, does the laser light up? any cracks in the pots plastic case?

I'v heard that when trimming the pots to far (certain pots) out of their position can burn the laser for good, that definitely goes for the pot on the laser, which should not be tweaked unless the laser is on it's last toes and need just some extra juice to crack it up.

And sometimes when adjusting the pots just the slightest, either by ear or by measuring it can make it go from read bad to not at all, when it stops spinning you know it's to far.

So which pot exactly is the one for the laser? Descriptions on the forum here don´t name it directly.... Is it the far left one when you look from the side, in normal position (cdrom on the table with board on the underside)?

[BlueBMW]

There is a pot on the laser unit itself, not the mainboard.  You should never have to adjust that one except in the most extreme of circumstances.

If you need a new laser, let me know.

[wolfman]

There is a pot on the laser unit itself, not the mainboard.  You should never have to adjust that one except in the most extreme of circumstances.

If you need a new laser, let me know.

Oh, I am sure I never touched THAT pot! Still I don´t see light coming thru the lens, so there must an issue. Don´t know where though.

One thing though I noticed today:
When I put everything togehter into the IFU, and I switched on the LT (with a game hucard in it) and right after the CDROM, it would spin up, and after the game had loaded, would stop. This is somehting it doesn´t do when I have a music cd in it - it simple would move the sled to check the for correct position, and then the unit goes off. Any hint?

Btw, thank you for your laser offer, I´ll get back to you, if I don´t get it sorted the normal way.

[BlueBMW]

Power the unit on open the lid and hold the little lid closed switch with a small screwdriver or whatever and press play and see if the laser tracks to center, turns on and then bobs up and down a few times.  That would tell is where in the process it is breaking down.

When it power up the first thing the system does is move the laser to center.  Once the center switch is tripped, the laser powers on and moves to check for the presence of a disc.  If a disc is seen, the drive spins up and the laser moves to read the TOC.  If no disc is seen, the laser stops and shuts off.

[wolfman]

Power the unit on open the lid and hold the little lid closed switch with a small screwdriver or whatever and press play and see if the laser tracks to center, turns on and then bobs up and down a few times.  That would tell is where in the process it is breaking down.

When it power up the first thing the system does is move the laser to center.  Once the center switch is tripped, the laser powers on and moves to check for the presence of a disc.  If a disc is seen, the drive spins up and the laser moves to read the TOC.  If no disc is seen, the laser stops and shuts off.

Sled checks for position, actually I CAN hardly see the laser turn on, and then there is nothing. After a few seconds the unit powers off. And then I cant get it to power on again (it only powers on again in the IFU  ), I have to remove the power plug.

So far it goes, but then nothing more.... 

[BlueBMW]

If you're getting a very weak laser then I'd suspect something with the laser or its connections, not the pot adjustments.

[wolfman]

If you're getting a very weak laser then I'd suspect something with the laser or its connections, not the pot adjustments.

Do you have a closeup photo of that laser pot? I actually don´t see any pot on mine - whether on the cable nor on the laser unit itself....

[wolfman]

What puzzles me is the startup-sequence:

I switch on the CDrom, the sled moves 1mm back and forth (innermost position), silence, moves 1mm back and forth, silence. Shutoff. I cannot switch it on again, I have to remove the plug, wait a few secs, and only then I can switch it on again. It also doesn´t matter which Audio-CD I use, always the same behaviour.

What is causing this?

[BlueBMW]

Can you take a picture of the postions of the five pots on the mainboard?

[wolfman]

Sure, here it is:

http://www.flickr.com/photos/65709578@N06/12192888985/#

Like I said, I am sure that I touched them without noticing during the cap replacements....