White CDROM2 Spins then "Please Set Disc"

[opticalnoise]

Now that I've got my Duo RX fixed, it's time to get this briefcase and CDROM2 unit running!

Here are the symptoms. I've got a working white PC Engine in an IFU-30. I've got a non-working CDROM2 that I bought with it. Opening up the CD unit, I can see the middle gear is fine and still moves the laser assembly, but the main screw-like part that moves the laser is dry as a bone. I re-greased it gently using white lithium grease and wiped away all the excess, moving the assembly back and forth a few times and rotating the gear/screw thing to get all sides of it equally greased. When I move the assembly all the way out and power on the unit, the assembly moves back to the center start position - verifying the middle gear is ok and grease is sufficient. The LED also shows PC.

The problem is on the screen I either get please set disc, or I get stuck on please wait. The disc is spinning, but it will not play music CDs, either. Also I am using an official CD game and not a CD-R. I then tried cleaning the CD lens with a Q-tip and some ISO 99% but results were the same - please set disc.

Reviewing this post and Keith's info there, I adjusted the laser settings to match the image. Results are the same on boot.
https://www.pcenginefans.com/forum/index.php?topic=23852.0

Since I know it's not the gears, the screw that moves the assembly or a bad disc, or the potentiometers (I think, hard to verify with this thing as I can't adjust them on the fly while the unit is powered) I am officially stumped.

Bad laser? Recap?

Below are pictures of the board, potentiometer positions before the adjustment to match Keiths, and pictures of the two cables which Keith mentioned could be messed up.

[Keith Courage]

I would start with capacitors. Here is a picture of the two rows of capacitors that typically go bad. Especially the 4.7UF ones near the volume dial.


Looks like there is some black leakage coming through from the 4.7UF caps on your board.

[opticalnoise]

Just ordered the cap kit - will post an update once I've done the recap. Thanks for the advice!

[opticalnoise]

Just replaced the caps you highlighted and we've got some progress!

Instead of please set disc, my game disc is giving me "Load Error!" and making a bunch of grinding noises. What's interesting is now it will play an audio CD, at least kind of. First time I tried the LED display showed a flashing "P- " then " - 1" alternating, then I was able to just get the track numbers and some audio. What's odd is the drive would start getting louder and louder, then suddenly the song would skip backwards about 10 seconds. Later tracks get jumpier and will start switching around. I've included the videos I took below. My thought is potentiometers. Either that or I need to not be lazy and just finish the rest of the recap.

Still, we've gone from 100% dead to it at least doing something!

Game disc:

CD Audio:

[Keith Courage]

Sounds like your Lens assembly isn't back in correctly or the center spindle got pushed down. The sounds I am hearing is the disc slipping or scraping as it spins, not so much the lens moving around.

Is it scratching up your discs?

There should be a black washer on the post screw closest to the center spindle. 

[opticalnoise]

I'd like to begin by saying that I am probably an idiot.

With that out of the way, I had some successes in repairing the CD unit. After fiddling with the potentiometers with the case off and a CD playing, I got the drive to successfully load and play a few games! CD audio tended to drop after 30 seconds or so but the games otherwise played fine. I got R-Type to play perfectly for some reason. The scratching sound also was largely gone, but I did still hear that sound that suggested the disc was spinning faster and faster until it stopped and the CD audio dropped. Potentiometers are still probably not in the exact right position, but I'm failing to find it.

With the newfound and probably baseless confidence from getting games to launch, I decided to go ahead and finish the recap, at least replacing all the easy to access ones and the 4.7 uf ones. Well, now I'm back to square one. The LED reads 'PC', the disc spins for about half a second and stops, then 'please set disc' appears. The obvious thought is I botched one or more of the capacitors.

Is there any easy or easy-ish way to tell which capacitor I messed up on the install? I was extremely paranoid about matching the right capacitor to each spot and ensuring it was in the correct polarity direction so I don't believe I got that wrong, but I will probably end up double checking each anyway out of paranoia. I also didn't see any solder bridges as I was also paranoid about that.

[Keith Courage]

Dumb question but make sure you didn't accidentally install the larger lens ribbon cable the wrong way. The contacts of the cable should face outwards so you can see them from the side of the drive while inserting the cable.