Project Dreamcast - Repair part 2

Last time I talked about the repair efforts on the Dreamcast GD-ROM drive.  The new laser will read CDs, but will not read game discs.  As I said, I don't know if the trimmer needs adjusting or not.  But before I go that route, I wanted to check the rest of the GD-ROM drive.

Removing the entire GD-ROM drive assembly reveals the circuit board for the GD-ROM drive.  The GD-ROM circuit board has a total of 10 surface mount electrolytic capacitors on it.

Capacitors are frequently the cause of old electronics going bad.  Is it possible these old caps are preventing the GD-ROM drive from reading discs?  I just so happen to have an ESR meter which is the best way to test a capacitor to see if it's good or bad.

When testing ESR values, lower is better.  A high ESR value means the cap is going bad.  Here is a table of the capacitors, their rating, the current ESR, and the expected ESR value.

As you can see, every single capacitor has a higher than expected ESR value.  So before I try adjusting the trimmer on the laser, I want to replace these capacitors with new ones and see if that helps.  Unfortunately I don't have any surface mount capacitors in my parts box, so I'll need to order new caps.  I'll continue repair efforts in my next post once the replacement parts arrive.

The last thing I'll mention is the manufacture of the GD-ROM drive.  The initial manufacture of the GD-ROM drives was Yamaha, but later on Sega switched to Samsung.  From what I've heard, the Yamaha drives are much more reliable.  From other repair work I've done, I've run into a lot of bad capacitors on Samsung products, so I won't be surprised in the least if the capacitors are the problem with this drive.