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The IIfx did have an incident where the 12V line on the PSU got shorted for a few seconds due to a faulty tantalum capacitor (which promptly caught fire and exploded). It may have caused damage to other components. Do you have any idea where to look in order to test the voltage theory? The...

I don't think that's the case because when I take the drive and attach it to another mac, it works fine. Likewise, if I take a drive from another mac and put it in the IIfx, it suddenly exhibits this issue. Because of this, I'm almost certain it has to do with something on the IIfx's motherboard.

I have a really strange issue with floppies in my IIfx. For some reason, the IIfx will read 1.44MB disks fine, but will only read some 800K disks. It reads 800K commercial software disks, as well as 800K disks that were formatted on the IIfx, but it won't read 800K disks that were formatted on...

I think it was just the speaker. I swapped it out with a different one and it sounds better. Part of me thinks the chime is still slightly off with the other speaker, but it could just be placebo. Interestingly though, the motherboard wouldn't read any floppies even with known good...

The thing is, with solid tantalum capacitors, manufacturers often recommend derating the voltage by 50%. While they'll technically work at up to the rated voltage, it can significantly decrease their lifespan. A 25v rated part probably would have been more appropriate. I'll definitely try...

I recently bought a IIfx. At the time, I thought I was fortunate because mine came with tantalum caps from the factory for everything except C9 and C24. I assumed that Apple was being smart and kept electrolytics on C9 and C24 because they were needed due to higher voltage resilience...

I don't have the AC ROM. The card I bought turned out to be an XK, for which I posted the ROM. Which card do you have that wants an AC ROM? Does your card have the 110MHz RAMDAC + EDO RAM?

Interesting... In case anyone finds it useful, I wrote a small python script that automates this process so you can get a readable ROM.

By the way, does anyone know if there's a certain way you're supposed to view these ROM files? When using a standard hex editor, I can't find any copyright strings. Do Macintosh ROMs use some special encoding, or does it have to do with something like endianness?

Turns out the card I bought was a Radius Precision Color Pro 24XK. Here's a dump of the ROM (2.0), in case anyone's interested. I also attached the Lapis ROM. As far as I can tell, the Apple AC card, ProX, and ProXK are all almost identical. They all have the same 3MB of VRAM and support the...

I recently bought a computer with a 24AC (or at least I think it's an AC, its hard to tell from the pictures so it might also be an X or XK but it has a red PCB). Once it arrives, I'll dump the ROM.

The other thread I read showed a ROM dumped from a 12" XP. Mine is the 7" one. Someone in that thread tried to use the 12" ROM in their 7" card and it didn't work, though they weren't sure if their card was faulty.

I recently found a rebadged Radius PrecisionColor Pro XP called the "LapisColor 24x Nubus." I'd like to swap in an original Radius ROM. Anyone have the image file for the Radius PrecisionColor Pro XP? I know somebody already uploaded the "non-Pro" version, but I'm looking for the "Pro" version.

Update: I fixed it! TLDR: It was the SWIM. Here's a summary of what I did: I downloaded a copy of the schematics for the SE/30, and verified with a multimeter that every pin on both the floppy connector and the SWIM was properly connected. All of the pins checked out OK. I also did the same...

The motherboard seems to be getting all voltages fine (+/- 5, +/- 12). The floppy connector also has 5v and 12v present. I didn't measure any -12v on the floppy connector, but according to the schematics it's not hooked up on the SE/30. Speaking of schematics, I guess I can use a multimeter to...

I've been working on repairing a Mac SE/30, and I've run into an issue. The computer won't read floppies, even with known working drives. A few months ago, it would read them fine, but suddenly it won't read them anymore. Whenever a disk is inserted, the drive will spin and occasionally seek...

That’s pretty much what I experienced. Guess that settles it, it’s probably a test pad. I guess I need to look around for more corroded vias then near the other capacitors then.

That's why I'm confused. Why have a trace+via that doesn't go anywhere? At first, I just thought it was possibly due to the fact that the schematics were reverse engineered, and thus possibly incomplete. However, it doesn't seem that way...

I'm pretty sure the via above R37 connects through on the other side directly to one of the pins of the oscillator. It also still has continuity on my machine, even though the blind via is gone, so I'm assuming the blind via goes elsewhere. Honestly, I'm beginning to think that blind via might...

I already got that part down. I’m actually trying to figure out the same in reverse, i.e. aftet leaving Y1 and going to the left side of c56, where does it go after disappearing into the blind via?