Macintosh Color Classic - display not turning on after Mystic / VGA mod

[sean1978]

Hey guys, I'm new kinda new here. I have a Color Classic that I picked up at a thrift store 10 years ago I'm working on. 

I got a nice fresh recapped and tested LC575 board from another member on this forum, and I had a coworker do the soldering for my VGA mod, here are pictures we took: 

My CC s booting, the power light turns on, and the HDD sounds like a normal boot sequence. After the HDD becomes silent, I can follow the normal key sequence to shut it down (soft power key, enter)

The Monitor never turns on. I'm a noob to classic macs and I have read the FAQ's, I'm pulling the analog board back out to look it over again at work next week. I'm just trying to figure out if there is something simple I'm missing out on. 

I was under the impression that I didn't need to change anything in the OS if I did the high res mod. 

I'm a calibration technician and half of my building is a test equipment rework facility so I'm pretty well equipped for troubleshooting hardware problems. 

 

[techknight]

did you recap the analog board? 

 

[sean1978]

No recap on the analog board yet. No visible signs of capacitor leakage on it though. I'll probably just order a set and knock it out. 

 

[unity]

Im guessing not, but that looks like a cut. It may just be the solder mask that came off. May be work a check.

 

[techknight]

that copper is definitely gone. Thats the underlying fenolic of the PCB. 

 

[sean1978]

I'll yank it out and do a continuity check. good eyeballs. 

 

[sean1978]

Yeah checked out out, continuity is fine. 

 

[unity]

Well since the analog board was handled to do this work, I would check over all the solder joint very carefully. In fact, I would reflow as many as you can. The older compacts, like the 128,512 & Plus, are known for bad solder joints.

 

[sean1978]

thanks for the tip. I'm gonna get a real good look this week.