Recent content by Garrett

You've got me thinking, and so I went through my stack of project boards. Sure enough, it's still there with a sticker "simiasmac - no chime". Dang! I need to get back to this board. Just too many other things in the way to complete first. I did end up fixing video on another board with similar...

If you've replaced all the caps in the power supply, it sounds like you need to clean it again. Some residual "fish" smell may be impossible to get rid of, but I suspect a cleaning will solve your problems (electrolyte fluid is conductive). Take the PSU out of its case and soak it in IPA (just...

Looks like an analog board issue for sure. Something with the vertical sweep. Have you verified your power supply voltage output is correct? I agree that starting with a reflow of all connectors on the AB is a good starting point. Also verify the 4-pin connector for the yoke is not burned and is...

Those are great options. Everyone has their own reasons, but I don’t use tantalums mainly due to cost (I can buy high quality electrolytic caps for 15% of the price of a tantalum cap) and pad shape. The boards we’re recapping don’t have tantalum layouts, and thus it’s easy to short out any...

Unfortunately, I have two analog boards with bad flybacks. Every once in a while, they will "click" and the picture will shudder for a moment. I tried an LC575 flyback as a replacement. While it technically works, I was unable to get the geometry adjusted correctly. Not super related to this...

If I am installing a new LED, I don't bridge the jumpers. If I'm using the amber LED original to the Mac, I'll bridge JP2. JP1 won't be bright enough.

I've never seen a photo of this revision logic board online, so I'm posting it here for documentation's sake. One obvious difference between this and the more common board is the lack of a 100uF 6V cap near the CPU.

I didn't find a guide for this model power supply anywhere, so I created my own. This particular PSU was removed from a Power Macintosh 7100, but is compatible with the IIci, IIcx, Q700, and so on. Enjoy!

Count me in! My case arrived yesterday as well and I'm excited to start building it out.

My bet is you'll need a new HOT (horizontal output transistor). I've replaced ~5 over the years. They fail in the manner you describe. Should still be available from sellers like DigiKey!

I know this is an obscure piece of Apple hardware, but I think they're neat because the color matches the old PowerBooks. I have two of these - one working and one not. Because I couldn't find any photos of the base online, I disassembled my defective unit to take a look around. For what it...

Nice score! One of my favorites. Embarrassingly, I've paid much more than that just for a black keyboard, so I'd say it's a bargain even with the logic board exploded. An LC550 board in there would be a great speed boost and wouldn't require modification to the back panel (to my knowledge)...

That resistor should be 4.7 ohms, which some meters may determine as low enough resistance to beep “continuity”. What does the meter say in resistance mode?

Wow- great find! Where’d you come across that manual? Are these scans of your original?

Great score! Caps are likely fine for now, but you’ll want to pull the PRAM batteries ASAP. Remove the keyboard (three screws from the back), then you’ll remove the speaker assembly (one screw upper left side, and you’ll find the green PRAM battery stuck to the backside of the speaker assembly!