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Here it is: . Mines currently stuck down with some strong double sided tape since I didn't want to drill any more holes. I'm sure you could extend it a bit to hook into where the power supply mounts. It's a tight fit, but it holds the board very snugly in place. 

A while ago I picked up this Macintosh 128K (Original repair thread above), and it turned out to be a HyperDrive 20 equipped system with a 512Ke board. After repairs the board was functional, but mine was missing both the hard drive and the power supply, and trying to find an original compatible...

Hello there - I recently tried installing 7.5.5 on my SE/30, and after 23 something floppies it installed just fine. Everything works correctly on it, but I noticed if I use the Shutdown or Restart options in Finder it bombs with just "bus error". The restart button on that message works just...

Finally found the fault, a 74LS166. Works great now

Really looking forward to getting this one working, never owned an original Macintosh before. Even more so to get the HyperDrive working, would be cool to have one of the few working units in the world  :beige:

Almost got this one working! Good few patch wires at this point, and a new 74LS166. We're now booting and are functional beyond a weird screen.  Since it works perfectly other than that, I suspect one of the 74xx ICs for the video generation are also faulty. I will get this stubborn Mac going :)

Taking another look after work and there's rotten traces from battery damage near the TSM IC. Started patching wires and now we have video on the screen, albeit just garbage. Does anyone have a nice high res schematic of the 512K board? The  only one I can find is the official apple one, but...

I picked up a rather interesting 128K and it finally showed up this week. It's quite an early one as it just has a Macintosh badge instead of the later 128K/512K ones, but was upgraded with a HyperDrive 20 rev 2 and 512K board. I've been trying to get it working, and after patching it's analog...

The only other part would be getting the GAL equations, as it has a handful of them on the board. Apart from that, you could probably figure it out if you had the time and clone it, although I'd imagine you could greatly simplify it with an FPGA. 

Hello, just wanted to share I've uploaded the v2.1 ROMs for the Radius 16/25 accelerator for the SE. I've not found another copy online, so hopefully this helps someone who wants to run Sys 7.1/7.0 on their SE with Radius card. ...

I recently picked up an LC that had a TDK power supply with lots of leaky caps. When powered on one of the big TO220 diodes would get red hot. The back side of the power supply is all black as well, presumably from being run when shorted. I've replaced all the caps, resoldered all the joints on...

What do you mean? The drive passed the test in Apple Personal Diagnostics, as well as the bad block test. May very well be going bad though, it is from 1990 after all. I have a SCSI2SD showing up sometime soon, so will probably switch to that at some point. 

Just to update, I finally found one program that seemed to work: SCSI Specialist. Initialised the drive, and I can now install Sys 7.1 without issue. No idea why the others didn't work

If it helps, I fixed a Mac Classic recently with the exact same error. In my case, it was the 74LS174 - a few of it's pins had corroded from bad caps and were no longer making contact. That little chip generates the timing for the CAS PAL in the corner of the board, and if it's not working...

I recently got my Macintosh Classic up and going again after recapping (analogue + logic). It passes the Apple Personal Diagnostics tests on the long RAM test, logic board test, and floppy test. It has it's original 40MB SCSI drive, and already had Sys 7.0.1 on it that worked just fine. I wanted...

Hello, I've picked up a Macintosh SE that was said to have a broken CRT, and did not power on at all. Indeed if I powered it on with everything connected, the 5V rail seemed dead and only 0.5V was on the +12V rail. Since I had them on hand, I replaced all the electrolytic caps on the analog...

Is there a compatible chip? I see it's Motorola branded, and I've found other ICs from them that were RTCs + SRAM. If not, I'll try the trading post here seeing if someone has a spare.  As well, do you know what the screen should look like without the ROM installed? Should it be blank, or...

Ah that's good to know then, I wasn't sure if that was an extra ROM for the built in System 6. I'm wondering if I've just killed the ROM and it's resulting in garbage on the bus, hence the garbled screen with it in. I can't seem to find replacements, so will try an find an EPROM that's pin...

Hello, I'm repairing a Macintosh Classic I picked up with battery damage. When I received it, it was totally dead (0V from the power supply on all rails), and it's battery had leaked on it's board. It has it's original SCSI drive and RAM expansion card with dual SIMMs.  I've since repaired it's...