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Faulty GD-rom PCBs

Posted: Fri Jan 19, 2018 4:28 pm
by Tarnish
Just something I was curious about after experiencing this a few times: How often do you guys run into a faulty Dreamcast where it turns out the GD-rom drive PCB is the one that is causing the problem?

Everyone keeps saying the laser is the Achilles' heel of the Dreamcast (which I don't doubt), I just found it a bit ironic that out of the 11 Dreamcasts I so far had my hands on, only 1 had a laser issue, while 3 had issues with the GD-rom dirve PCB. 1 had a broken lid sensor switch, while 2 seems to malfunction in weird ways:
- one of them recognises the discs fine, but after getting to the SEGA logo in the boot sequence, it goes back to the main menu, and also when opening the disc lid, it spins the disc in the opposite direction instead of stopping it
- the other is pretty similar that it recognises the discs fine, but after the SEGA logo it just goes back to the main menu. Also, when trying it out with an audio CD, it seems to read and play it fine, except it doesn't output any sound, even tho the boot up and menu button sound effects play, so it's not an issue with AV cables. This one doesn't spin the disc in the opposite direction when opening the lid however, and on rare occasions it does boot up games and plays music properly.

(Just to note, it's definitely the boards that are at fault in these cases, as I did troubleshooting by swapping out the laser pick-ups, motors etc. to known good components to see what is actually causing the problem.)

So it's probably just my luck, but it never really dawned on me that the GD-rom drive board can go bad as well. The laser, motors, ribbon cable, PSU are the usual suspects.

Re: Faulty GD-rom PCBs

Posted: Tue Jul 07, 2020 8:26 pm
by simfan
I agree with your point of view. When I receive a fault unit which cannot load disc but spins, I will check the ESR value of the capacitors, and replace those with high ESR value. I cannot prove anything but I trust this build a stable ground for me to install and tune the SPU 3200 laser unit.

Re: Faulty GD-rom PCBs

Posted: Mon Sep 07, 2020 10:29 am
by simfan
Recently I repaired two DCs which not reading discs by recapping those capacitors with ESR over 20oms. Now they read discs smoothly and silently.

Re: Faulty GD-rom PCBs

Posted: Tue Sep 15, 2020 2:42 pm
by butoia
simfan wrote:Recently I repaired two DCs which not reading discs by recapping those capacitors with ESR over 20oms. Now they read discs smoothly and silently.


Hi, can you post a scheme with the capacitors to recap? Thanks in advance!

Re: Faulty GD-rom PCBs

Posted: Wed Sep 16, 2020 3:49 am
by fafadou
https://dragoncity17.wordpress.com/2013 ... parations/

You have all informations here and spare components for 3€.