Recent content by CBM1084

Hello, I have a Macintosh 128k which has some RAM related fault. With all the original RAM, it starts up with a sad mac code of 040001, which I understand suggests a bad RAM chip at position F5 (I've done some probing with an oscilloscope and don't see any other obvious issues). The original...

Thank you for the advice - it turns out the solution was actually much simpler and just seems to be a weird quirk with the way these iMacs boot. As soon as I swapped the hard drive in from my working G3, it booted just fine (it didn't even seem to be trying to boot before that). Of course, as...

I looked it up briefly but don’t see much information on that. Any chance you know a bit more about how that would work? Thank you

Hello, I just got a lime 400 MHz iMac G3 which was working great running Mac OS 9.2.2. I wanted to boot it into Tiger but the SSD I was going to put on it is still on the way, so I tried to boot it over firewire from my G4, but forgot to check if the firmware was updated on it (I doubt it was...

Yeah I did that and there was one missing connection but fixing that didn't change anything. The video problem seems to have gotten worse, and from what I can tell it comes in and out when i manipulate the board around where the glue chip is. I've triple checked it for bad connections but...

Yeah you were right, not sure why I jumped to the conclusion that it was at the CPU honestly, in fact the problem was quite obvious if I had just looked. The previous owner I guess had desoldered the VIA chips and had put them back on with bridges and missing connections all over them. The...

Yeah those schematics have been pretty helpful, and that diagram you sent is useful as well. The short is reading close to 0 ohms between the pins for data lines 28, 29 and 30 at the CPU (interestingly all in a line in the diagram attached), which is why I suspected it was around here. It...

This is useful information, thank you. I am really enjoying the process but I'm really stumped by this short on the data lines. From what I can tell it seems to be around the CPU area but I really don't know for sure, and I'm very nervous about trying to desolder it... not to mention it seems...

Hello, I know I'm one of many facing troubles with Mac SE/30 repair, but I'm a bit stuck with the board I'm working on and wanted to get some suggestions from the community. I have two SE/30 boards, both of which got battery bombed. One of them is pretty much destroyed beyond the point...

Hello, I recently purchased an eMac on ebay that was listed as "in great working condition", but when it arrived it was in fact not working properly. The computer itself seems to work fine but the display is completely distorted, shifting and flickering constantly so with half the picture off...