8bitdomain.com Svideo mod, issues

[AtariKari]

I read through the "easier 7800 Composite video thread and thought about posting this in that thread, but it seemed a little OT.

 

Many moons ago I placed an order for the Rev. 2 board (link here) and recently received and installed it. I'm a novice at these types of projects but am good at following directions...so, when I put it all together the Svideo looks amazingly crisp but is in black and white, and the audio does not work except for briefly when I seat/unseat the Mod chip.

 

I've emailed Mike from 8bitdomain and he hasn't been very responsive . If someone could give advice how I could troubleshoot I'd greatly appreciate it. I'd like to get back to playing games

 

I checked my solder points, all of them appear to be clean and secure. In order to seat the board, I had to dremel the edge of the red plastic tube that sticks up from the board (an example of this part is shown in the center of the attached pic), could that have anything to do with it? I only sanded the plastic part of the tube so I doubt it.

 

That's about it. I've been poking at this for a while but can't figure out a good way to systematically approach it. Thanks very much for your help.

Edited October 11, 2008 by AtariKari

[+Mitch]

That red tube is part of the audio circuit. It sounds like you may have damaged it.

You said the S-Video picture is in black and white, how does the composite or RF picture look?

 

Mitch

[AtariKari]

That red tube is part of the audio circuit. It sounds like you may have damaged it.

You said the S-Video picture is in black and white, how does the composite or RF picture look?

 

Mitch

 

Thanks for the reply.

 

Ugh.

 

Here's a blurry webcam shot of the red tube on my unit. The arrow indicates where I sanded. If I did mess it up, is there another way to grab the audio? To clarify, the audio output sounds like an ungrounded signal--lots of buzz--although I have grounded the line per the instructions.

 

The composite does not work, and the RF output is just a black screen now (it worked before the mod).

Edited October 11, 2008 by AtariKari

[+Mitch]

I'm sorry, I can't really tell from your picture. Since the composite isn't working either I suspect something is hooked up wrong on the video circuit as well. Is there any way to get a clear picture of the connections with the mod board unplugged?

 

Mitch

[AtariKari]

Unfortunately I'm stuck with a webcam for a while and it can't even come close to doing macro pics.

 

Although I think I followed the directions for the mod correctly I'll over start from scratch and see how it goes. I'd rather not bog this thread with grainy close ups

 

If that fails I'll try again to get some legible shots...

[walter_J64bit]

I'm having the same audio issues so I don't use the moded 7800 much but I do have an un-moded 7800 that works like a dream with the RF out!

[AtariKari]

Epilogue (I hope!): I gave up on poking at this after a week. Mike at 8bitdomain offered to fix it for free if I shipped the unit to him, which I thought was a very decent thing to do and wanted to note it here.

 

I'm interested to see what was messed up and would be happy to try and help other ppl out once I get it back.

 

That's all