Modded DC with distorted sound, already tried most common solutions

[Seroczynski]

Hi guys, I've been searching all over for someone who is able to push me in the right direction. Tried several forums, but no luck so far. Hopefully someone here will be able to identify the problem I am having.

I live in Europe but started working on a NTSC-U Japanese Dreamcast. Replaced the stock fan with a Noctua fan, installed a rechargeable battery, PicoPSU, GDEmu clone from China and a DCHDMI.

I've followed the official instructions in order to install my DCHDMI, including the IGR Button Reset option (the green wires on the backside of the Dreamcast motherboard).

There were some issues with my first GDEmu clone where some games wouldn't properly work. Crazy Taxi had problems with sound not working properly (cut out) and textures not loading in time or not at all. I've replaced the oscillator crystal but somehow managed to break the entire thing so I've replaced it with another GDEmu, which has the proper crystal installed from the get-go.

Now when I start my Dreamcast, I am getting distorted sound over analogue and no sound at all over HDMI. The video is great, both through HDMI and analogue. No errors show up in the DCHDMI test. I want to stress that this was not an issue with the previous GDEmu clone, but now seems to be the only issue.

• I've already sanded down the PSU connector and tried with both the PicoPSU and an original Dreamcast PSU.
• Measured voltages at the PSU connector, seems to be fine.
• All the DCHDMI connections have been checked with a multimeter after installation and there were no shorts or loose connections.
• I've also tried putting the original GD-ROM back in. Distorted sound is still an issue.
• Tried different TV's

Here's a few pictures of my Dreamcast.

Spoiler

I'm not sure what else the issue might be. I really want to get started on my games with this DCHDMI modded console. Should I get a replacement Dreamcast motherboard and DCHDMI flex cable to rule out a defective motherboard connector?

 

[Druid II]

I'd redo the soldering, it sounds like one of the sound data lines are shorted.

 

[Mathieulh]

Hi guys, I've been searching all over for someone who is able to push me in the right direction. Tried several forums, but no luck so far. Hopefully someone here will be able to identify the problem I am having.

I live in Europe but started working on a NTSC-U Japanese Dreamcast. Replaced the stock fan with a Noctua fan, installed a rechargeable battery, PicoPSU, GDEmu clone from China and a DCHDMI.

I've followed the official instructions in order to install my DCHDMI, including the IGR Button Reset option (the green wires on the backside of the Dreamcast motherboard).

There were some issues with my first GDEmu clone where some games wouldn't properly work. Crazy Taxi had problems with sound not working properly (cut out) and textures not loading in time or not at all. I've replaced the oscillator crystal but somehow managed to break the entire thing so I've replaced it with another GDEmu, which has the proper crystal installed from the get-go.

Now when I start my Dreamcast, I am getting distorted sound over analogue and no sound at all over HDMI. The video is great, both through HDMI and analogue. No errors show up in the DCHDMI test. I want to stress that this was not an issue with the previous GDEmu clone, but now seems to be the only issue.

• I've already sanded down the PSU connector and tried with both the PicoPSU and an original Dreamcast PSU.
• Measured voltages at the PSU connector, seems to be fine.
• All the DCHDMI connections have been checked with a multimeter after installation and there were no shorts or loose connections.
• I've also tried putting the original GD-ROM back in. Distorted sound is still an issue.
• Tried different TV's

Here's a few pictures of my Dreamcast.

Spoiler

I'm not sure what else the issue might be. I really want to get started on my games with this DCHDMI modded console. Should I get a replacement Dreamcast motherboard and DCHDMI flex cable to rule out a defective motherboard connector?

You used way too much solder, most of the connections happen under the ribbon cable pins. You need redo the AICA (the upper IC in your picture) joints, you probably have a short/bridge in there because of the amount of solder you added, I would check for bridges using a continuity tester if I were you.