Bought a broken PC Engine CDROM unit, wanna help me fix it?

BlackandBlue · 04/16/2009, 04:31 PM

So, I bought a broken IFU and CDROM unit off ebay just to see if I can salvage the poor thing. I dont have an AC adapter for the briefcase, but I'm going to save diagnosing that for another day.

As for the CDROM unit, I was hoping that it would be something stupid and easy to fix, but something is telling me I just bought a paperweight. When I power it up, nothing happens. The CD doesn't spin, the laser doesn't move (gear is OK though) and there is a "0" for the track display. I opened it up and everything appears to be in order. No loose wires, none of the ICs appear damaged, no cracks in the board, and no solder resin spots (sometimes see those when a resistor overheats and dies). For reference, I am using my TG16 power brick to test.

So, I guess my first question is, when not in the IFU, is it normal to see the "0" under track listing? I am hoping so, since it is not attached to the IFU (where it should then say "PC"?). Does this sound like a dead laser issue (maybe the unit has no idea that there is a music CD in it, since it cant read it)? Or perhaps a dead spindle motor (which it appears to be the same unit that is in the PS1, which I have 2 on order, since I have a 3DO Im going to try to fix). I want to say the unit itself is OK since it powers up, but something with the drive/laser is dead.

Any comments and input would be appreciated! If you need me to take any pictures or test anything out to help further, please let me know. Thank you!

pceslayer · 04/16/2009, 04:35 PM

It should display a track number(starting with 0) when not connected to the IFU.

It works like a standard CD player when disconnected.

BlackandBlue · 04/16/2009, 04:54 PM

That should be good news. Hopefully it means either a dead motor or laser.

BlackandBlue · 04/16/2009, 06:32 PM

Ok, I disconnected the spindle motor and the worm drive motor and gave both 3 volts. Both spun. So, it's not one of the motors. Hopefully someone can confirm this type of behavior being that of a dead laser, else I'm screwed.

Zeon · 04/16/2009, 06:47 PM

Can you hear the motor physically moving the laser? Try moving the laser all the way to the end of the track, and see if it returns home when you put a cd in and try to play it. Check to see if the spindle is not physically too low, if it is it won't catch the cd and spin it. The spindle getting too low is a fairly common issue. Remove the spindle from the motor, and press back on to where it catches the cd. It's a pain to find the sweet spot.

Also try holding down the lid sensor and pressing the play button, what does the laser do? If the eye pops up and down a few times I'll bet you one or both of the internal ribbon cables is reversed. There are 2 and they can go in both ways. This makes a total of 4 possible combinations, but only one is correct. Also clean the laser eye with a rubbing alcohol soaked q-tip and let it dry before powering on.

BlackandBlue · 04/16/2009, 07:15 PM

Ok, I put it all back together and routed the door switch out of the case. I moved the laser out alomst all the way to the end and when I turned the unit on (without a cd, switched in closed position), it moved back to the inside. I cleaned it with alcohol and a q-tip too. The laser does not move up and down when starting. I tried it multiple times. I don't think the spindle is too low, as the spindle motor doesn't even try to spin. I checked the ribbon cables and they are inserted correclty (contacts towards on the ribbon are facing the plug's side with the exposed metal).

BlackandBlue · 04/16/2009, 07:31 PM

I just checked on my PS1. When I hold down the door switch and power on the unit, the laser moves up and down to try to focus. The PCE CD doesnt act this way. I know that the laser is a diode, so if its open (blown), it cant move to try to focus. Im hoping that a new laser will fix it. Now I just need to find one that isnt a ton of money. I know I can get an old Sony discman, but with my luck, the laser will blow in a week anyway.

Edit: Ordered a KSS-220A from Electronix, so we shall see if it works in 2-5 business days.

Edit2!: Bought an AC adapter from radio shack and tested the IFU. Works fine. When trying to access the CD it displays "PC" on the CD ROM unit.

BlackandBlue · 04/28/2009, 12:29 AM

Well, this one got saved from a dumpster! I got the replacement CD lens from Electronix.com and put it in today. I figured while I was at it, I might as well replace the CD spindle/motor with the newer design. Everything worked out flawless. Not to mention I also de-yellowed them using the retr0 bright process, pointed out to me by Sparky (https://www.pcengine-fx.com/forums/index.php?topic=6499.0), while waiting for the lens to arrive. All in all, its like I got a brand new unit. I couldn't be happier.