Dreamcast: Low power to controllers

[crabhammer]

I can use a VMU in either slot with only P1 controller connected. If I connect a controller to P2, the P1 VMU screen dims and it starts beeping every few seconds. It throws an error during gameplay (observed in SoulCalibur) and during any attempt to save. P1 and P2 controllers function as intended and the error(s) vanish when the VMU is removed (although I can't save without one).

If I unplug P2, I can save and play all I want. I don't see any obvious issues with the controller ports/board. Everything checks out with my multimeter. I'd like to rock some SoulCalibur with my friends, but I'm pulling my hair out trying to figure this issue out.

[tafk]

Do you have a video of the error? Is it controller specific? Does P2s VMU get power?

[crabhammer]

It doesn't seem to be controller or port specific.

If I plug more than one VMU into any combination (Slot 1 in P1 and Slot 2 in P4 for example) the controllers go dead until the VMUs are removed. I'm beginning to wonder if I used too much resistance when I repaired the controller board, but according to the color codes and my math, it's correct.

I tested the power supply board outside of the unit and it checks out.

[tafk]

Yeah it sounds to me like the VMU might be drawing too much power when plugged in and this is causing the controllers to lose power? Sadly this is the most I can help with as I have never actually operated on a dreamcast to this extent before...

[crabhammer]

After Google searching, testing and pulling my hair out, I found the solution to the issue as well as the cause.

The Dreamcast Junkyard community posted something to their Facebook page about improper controller board repair and how most tutorials are far off the mark with their fixes. I followed one such fix and replaced a resistor/fuse that limits current to the controllers.

What I have essentially done "fixes" the dead ports but limits the current to the controllers so much that only one at a time works. I'm going to order some resetting fuses to replace the resistor in every single DC I own.

I'll post a proper shakedown of the fix once I have it done.

[DreamsDied13101]

Thanks for the update post on this. I had never had this problem, but now I know to look out for a valid repair option if so many are incorrect online.

After Google searching, testing and pulling my hair out, I found the solution to the issue as well as the cause.

The Dreamcast Junkyard community posted something to their Facebook page about improper controller board repair and how most tutorials are far off the mark with their fixes. I followed one such fix and replaced a resistor/fuse that limits current to the controllers.

What I have essentially done "fixes" the dead ports but limits the current to the controllers so much that only one at a time works. I'm going to order some resetting fuses to replace the resistor in every single DC I own.

I'll post a proper shakedown of the fix once I have it done.

[crabhammer]

Thread necromancy aside, I have had the parts in for a few months, but haven't had the time away from work to sit down and take the time to execute and document the fix. I plan to get that done asap.

Seeing how many DC repair sites/blogs/forums out there are peddling the fix I followed, I can't get it done soon enough.