Dreamcast ''No Video Output/Black Screen'' Repair Tips Thread

[SparkThaMetal]

Hi all. I've been seeing many more Dreamcast's with the '' no video output fault'' as of late. Either straight from boot or during gaming. And the price for our beloved machine is generally increasing.

So I thought it would be good to have a thread with all the video output faults people have experienced and how they fixed them, to try and help save as many Dreamcast's as possible.

I myself am aware of a few causes of it (feel free to correct anything):

1.Psu failing/acting up:

-Cause 1-Failing/leaking caps on psu. Fixes-Re cap PSU/Replace PSU/ Buy dreampsu/picopsu etc.

-Cause 2-Dirty psu connecting pins/bad connection between pins and psu board.FIX 1=Clean pins with isopropyl. Fix 2:Can also apply pressure to pins to bend them slightly to make better contact with connector when seated (havee to bend in diff direction for PAL machines)


2. Fan not detected by dc:
Cause 1-Fan simply unconnected. If the fan isnt connected then you wont receive video. FIX=reconnect fan.
Cause 2-Fan connected but not detected/fragile connection. Flakey/loose fan connector on controller board. they can come loose or start having dodgy connections. FIX 1= reseat fan connector. FIX 2- If that fails try and resolder/reattach the connector.


3. Video Encoder Chip Fault- FIX. Replace video output chip. Available on aliexpress?

4. AV port fault- The AV port and the traces/points behind it can have issues sometimes. FIX. Clean AV port with isopropyl. Fix 2. Find any issues with traces and components behind the AV port. This guy used a jumper wire to fix his https://youtu.be/-oMSwLmzb1c


Im sure I'm missing a few causes and symptoms here , so feel free to add. Thanks

[Londinium]

Useful thread!

[SEGA RPG FAN]

I'll add: if normal av outputs work (e.g composite) but no picture with VGA box or anything else that draws power, there's an SMD fuse on the 5v output that can blow.

[andreen]

I'll add: if normal av outputs work (e.g composite) but no picture with VGA box or anything else that draws power, there's an SMD fuse on the 5v output that can blow.

Apply gentle pressure to pins to slightly bend them, improving contact with the connector when seated. (Note that bending direction might differ for PAL machines.)

[RobisMarshall]

I'll add: if normal av outputs work (e.g composite) but no picture with VGA box or anything else that draws power, there's an SMD fuse on the 5v output that can blow.

Apply gentle pressure to pins to slightly bend them, improving contact with the connector when seated. (Note that bending direction might differ for PAL machines.)

Can this fuse bereplaced?

[lilycoll89]

You're absolutely right about failing capacitors, dirty connections, and bad solder joints on the PSU being common culprits. Replacing or recapping the PSU can be effective, but consider alternatives like DreamPSU or PicoPSU for modern and reliable power solutions.

[dannyfernasty]

PIcoPSU worked best for me when I had this issue.