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Hey All, hoping someone can help point me in the right direction. I'm working on a later revision iMac G4 that has a dead power supply. This is one of the later "USB 2.0" 1Ghz revisions and it has a Samsung power supply unit in it with model number: PSCF161101A. The first thing I noticed was...

Hey Colin, I had a similar issue with a Classic AB, recapping it fixed the voltage problems it had but I still had the shake especially when the power supply was first turned on. I ended up replacing the DP3/DP4 diodes as well as the OP1 optocoupler and that seemed to do the trick - it was...

Hey @Garrett, are they the original caps still on there? I’d suggest you swap out the surface mounts out even if they don’t look too bad.

Success!!! The jailbars are gone - the UC7 VRAM chip was the culprit. I’ve replaced both UC7 & UC6 just for the sake of completeness but the fault was 100% the UC7 chip. I ended up cutting the legs on the old chips a then heating up the remains of the old pins and pulling them out. Then...

Ok, I think we might be on the right path with these VRAM chips.... Today I cut/disconnected the 5V leg of the UC7 VRAM chip (pin 12) and turned the machine on and jailbar fault looks exactly the same even though that whole chip has been disconnected from the 5V feed. Then repeated the same...

Nah I have swapped UE8 with a known good chip

Thanks @techknight - I have found a source for those VRAM chips so have a couple on order. I think that is my next step to try swapping them out, when I look at the current VRAM chips under a microscope on a few of the pins there looks like there are some signs of rust where the pin leg goes...

If you're analog board has not been recapped and is still original, then it most certainly will need to be. The good thing about the classic analog board, though is you can check the voltages easily using a multimeter on the hard drive power connector. So as a starting point I would make sure...

Hey @Redsward, check out Mac84’s recent stream - Steve is doing some work on a Classic II and there is some great troubleshooting tips in it which may help you out here - especially the tip about the power connector: https://www.youtube.com/live/vnAtXpDoirQ?feature=share

Thanks @Drake - I’ve since gone through and removed UA8 through UG8 from the board, throughly cleaned the board as it did still have some cap juice under the chips. I then went through and checked all the traces from all those chips to ensure they all get where they are meant to as per the...

Another quick thing I will just add - I was doing some testing this evening between my grey screen board and the totally dead board by swapping the ROMs - similar to you it didn't change anything. But I decided to try running the board without the ROM chips installed at all and see what that...

Okay, that is quite different than what I was thinking it was. That doesn’t really look like the board is even starting to try booting into the ROM at all. My version of the grey screen problem looks like this……

Hey all, hoping someone can give me a bit of a steer on a problem I am trying to solve with an SE/30 I picked up last week. The logic board itself thankfully had a non-leaking original battery installed which I was relieved about - but the capacitors had done some pretty serious leaking, and...

I know I have certainly seen the "no audio" issue (that Adrian also hit in that video) on the CC before when those grounding springs were making intermittent contact with the grounding shield. In that case a bit of a wriggle of the board seemed to fix it and the audio returned. On the board...

If you find a solution to this Colin I would love to know - A few weeks ago I recently got a Colour Classic that was totally dead. Ultra-sonically cleaned and recapped it and it sprung to life and started working perfectly. I ran it for about 6 hours over the course of a couple of days to...

Hey everyone, I'm going to be travelling soon for work from Aus over to the US and visiting both LA & Las Vegas. I've seen lots of videos on the YouTube of old computer recycling stores in the US which can often have a lot of vintage computer equipment. I was wondering if anyone knew of any such...

So I finally got this Analog board to stabilise. After getting my hands on another one I was able to do some comparisons. What I have discovered is these boards really do not like to run without any load on them and if you do run them like what I did in that video you see the voltage...

Hey, I had cleaned up the flux I used with isopropyl locally in the areas I was working on..... but it's a good point. I haven't tried giving it a good scrub as you have suggested here. I've now done that this afternoon and I have the AB air drying. Will give give it a good going over...

Hey everyone, hoping someone can give me a steer on a problem I am facing since recapping my Colour Classic Analog Board. It was working OK beforehand, but I decided to do some preventative work on it and replace the caps. After recapping all recommended caps (as per the Recap-A-Mac guide)...