Help with my Mac LC

[mooplef]

I recently just got the TDK power supply working, and it took me quite a while. Now I'm moving on to the logic board, and it has problems too. Once I first plugged in the working power supply, the fan and hard drive spun up, and nothing else. I took out the battery for about 30 seconds, put it back in, and fiddled around with the RAM a little bit when it started making startup chimes when I turned it on. One of my RAM sticks had corroded pins, so I bought some replacements. When I populated one of the slots with either the old working stick or new stick of RAM, it would make the startup chime and then a few more chimes immediately after that. When I populated both slots with the new RAM, it only made the startup chime and no other chimes after that. I haven't been getting any video, but I also don't have a good monitor and I've just been using a VGA converter. Then when I turned on my oscilloscope (just a 20MHz 2-channel analog scope) to see if there was any data on the CPU, I was testing some pins and getting data on them when I realized that it didn't make the startup chime anymore. I'm still seeing data on the CPU, but taking out the battery and messing with the RAM didn't bring it back like it did the first time.

This computer has had the battery replaced, and the logic board has been recapped. Interestingly enough, it came with a Sonnet Technologies Presto LC card and fully expanded RAM and VRAM. I just want this thing to work. This computer will be the end of me.

 

[mooplef]

Also I never heard the head and the hard drive move anywhere. The hard drive will just spin down about a minute after turning it on.

 

[luRaichu]

I don't think the internal Quantum HDDs can spin down... But if it's a Quantum it's certainly got stuck heads due to melted rubber bumpers inside. Turns to goo after a long time

 

[mooplef]

I don't think the internal Quantum HDDs can spin down... But if it's a Quantum it's certainly got stuck heads due to melted rubber bumpers inside. Turns to goo after a long time

Well that's unfortunate. Thankfully I can get refurbished drives from ServerWorlds if this one doesn't end up working, if they offer capacities that are low enough for the LC to recognize. Do you know the maximum capacity that I could replace this hard drive with?

 

[Nixontheknight]

Well that's unfortunate. Thankfully I can get refurbished drives from ServerWorlds if this one doesn't end up working, if they offer capacities that are low enough for the LC to recognize. Do you know the maximum capacity that I could replace this hard drive with?

I'd personally recommend shoving a PiSCSI or BlueSCSI V2 in there. You may not get the sound, but you'll get a lot of features, such as emulating a CD-ROM drive or a SCSI ethernet adapter

 

[mooplef]

I'd personally recommend shoving a PiSCSI or BlueSCSI V2 in there. You may not get the sound, but you'll get a lot of features, such as emulating a CD-ROM drive or a SCSI ethernet adapter

Yeah, that's probably a better idea. I do like hard drives more just for authenticity's sake (I recently got a hard drive from ServerWorlds for my 486 system), but I'm also not planning on using this computer as much as the 486. This was just a $20 find on eBay that I impulse-bought.

 

[Nixontheknight]

Yeah, that's probably a better idea. I do like hard drives more just for authenticity's sake (I recently got a hard drive from ServerWorlds for my 486 system), but I'm also not planning on using this computer as much as the 486. This was just a $20 find on eBay that I impulse-bought.

In the long run, yeah. I have an LC III that I shoved a SCSI2SD in because it came with no hard drive. One of these days, I might pull it out and put together a BlueSCSI V2 with a Pico W so I can get WiFi with my LC III, and maybe keep that PDS slot open for if I find that Sonnet Presto accelerator you mentioned

 

[robin-fo]

Has the logic board been thoroughly cleaned (with alcohol) after recapping?

 

[mooplef]

Has the logic board been thoroughly cleaned (with alcohol) after recapping?

Yes, several times.

I also double-checked my power supply rails because that thing has been a pain in by back, and now 12v measures at 14v. I know what the problem is, it's just a small resistor, but I just hope that it didn't fry anything.