Recent content by Arisotura

Lil' update... I ordered replacement chips for the ROM SIMM, I have been given PLCC ones instead of SOIC, so... Probably the most cursed ROM SIMM out there, but the connections are all good. (I have since gotten one of these SIMMs that can be reprogrammed, in case this thing fails again) I...

Status update on this: I suspected the fault with my IIfx could be either the CPU, the FPU or the ROM. I got a SOIC32 adapter so I could test the ROM chips on the ROM SIMM. Turns out one of these is bad. I'm going to see if I can get a replacement.

I just used these, they fit well. The original buttons aren't anything fancy, they're similar push buttons but mounted at a 90° angle, and they rest against a plastic holder that can be separated.

As title says. Basically, my IIfx isn't giving any sign of life, and here's what I observed so far: UJ7, UK7, UL8 and UN9 get really hot. Not sure if that's indicative of any fault? These chips seem to be GAL16's. I'd understand why one would fail, but... all of them, at once? So I'm unsure...

Well, for the first part, turns out UI18 went bad. After replacement, the start-up circuit is behaving normally. However, I'm still not getting any sign of life... blarg.

Long time no see, thread... seems some of it has been lost? Regardless, I decided I was gonna reorganize my apartment, and put the IIfx to use, so I installed it with the TV for a test run... ...and somehow, it died. I've been trying to troubleshoot it, but I'm clueless so far. First fault...

Just wanted to chime in about this: I have observed, atleast on the LC, that the motherboard uses separate digital/analog ground planes, and these aren't directly connected -- instead, the analog ground goes through the RF shield and the power supply case. I wonder if replacing the power supply...

So what have we been up to since the last time? - My IIfx now has a whopping 20MB of memory. I basically sacrificed the extra 1MB SIMM I had, seeing as it wasn't gonna be useful for anything anyway, and replaced the chips with compatible 4MBit chips. I had to rewire one connection, too. I'm...

Thanks :P Regardless, here's where we are this morning: The through-holes are installed. Except for the RAM socket, I will do that one after I have received and installed the F573 -- it would hinder my already limited ability to solder that SMD chip in place. As usual, all connections have...

Lil' update! Picture might not be that good, but basically: * all SMD parts are resoldered, except for the F573 for which I haven't received the replacement part yet * all damaged traces should be fixed, everything had its connections checked thoroughly before being soldered back * a few...

Seeing as I can't really do much until my orders arrive, I looked closer at the RF shield... The rust on the RF shield is typical of a Maxell bomb, from what I've seen. I hadn't noticed how bad it was near the speaker. I might need to get this shield out somehow, derust it and maybe polish...

Only real difference I can see are that revision A has some jumpers that are missing in revision B. Rev B also doesn't have the list of names at the top. The chips under the RAM slots are slightly different (yellow instead of black on rev B), but I saw some pics of rev B motherboards with black...

I was looking around on eBay when I saw this one, so I thought, hey, why not give it a try. It was provided as 'not working' and having undergone battery leakage, but it did not look that bad... Some of these components aren't looking too hot, but compared to the pics of Maxell-bombed Macs...

I ordered some supplies so I can redo my soldering on my Mac LC motherboard the right way. In the meantime I figured I'd focus on the power supply, which is the typical TDK one. Of course, it had crapoed capacitors, so I replaced all the output-side capacitors and cleaned up the mess. The power...

So a while ago I got a Macintosh LC, power supply was dead but in the meantime I was able to get it working by connecting it to an ATX power supply. It had no sound but otherwise seemed to work fine. Obviously the capacitors were at fault there, so I got new capacitors and set to work... ...