68kMLA Classic Interface
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| Mac IIsi ... I fried it all :( | |
| Posted by: ironborn65 on 2022-10-01 01:55:36 I need to calm down now.... this is hard to write 🙁 I was playing around a Mac IIsi, let's say I was "distracted "and I unplugged and replugged the floppy drive while it was on, and the screen froze. Shame on me! Now the only thing it does is the happy chime... what an irony. Same thing even if without RAM, battery, floppy, HD. If I re-press the start-up button I have a white screen. What did I fry? 🙁 .... what the $#&%% | |
| Posted by: joshc on 2022-10-01 03:09:17 The internal floppy drive? You may have fried the SWIM chip. The easiest way to find a replacement is from another IIsi board, though the part was probably shared with other Macs so there will be other machines you could steal one from too. See the dev notes for the IIsi here https://cdn.preterhuman.net/texts/computing/apple_hardware_devnotes/Mac IIsi.pdf With the machine on, is the SWIM chip getting very hot? | |
| Posted by: ironborn65 on 2022-10-01 05:51:16 Hi @joshc , yes the internal floppy. No chips are hot, only the CPU and the two VLSI are a little warm, the rest are dead cold. | |
| Posted by: imactheknife on 2022-10-01 14:34:40 I have a chip possibly from a dead board. Also have a recapped board looking for a home "cough cough" 🙂 | |
| Posted by: imactheknife on 2022-10-01 14:35:26 try a pram reset? | |
| Posted by: Phipli on 2022-10-01 14:47:25 Really daft thing that makes no sense, but just for the outside chance. Take the battery out, and put the computer on a shelf for a few days. Play with something else for now 🙂. Next weekend, try the machine again. I was absolutely certain I'd toasted an 8600. Nothing would fix it. Zapped PRAM, removed battery, cuda button, swapped RAM, swapped processor, removed cards and unplugged disks... I gave up. A week later I poked the power button and it booted. It probably won't help, but what I mean is leave it to settle and retry before you do anything like spend money or soldering or anything, just in case. Good luck, regardless of what happens there is always a fix. | |
| Posted by: jajan547 on 2022-10-01 22:29:38 Hey you're In luck I have a ton iisi chips sitting here.   1. Apple 343S0061-A VLSI SWIM Floppy Controller 2. Apple 344S0063-A VLSI Sound Chip 3. Apple 343S1020-A NuChip 30 NuBus Bridge 4. Apple 342S0440-B ADB Controller 5. AM53C80AJC SCSI Interface Controller 6. AM8530H-8JC Serial Communications Controller 7. Apple 338S6523 VLSI VIA Chip 8. Bt478KPJ66 DAC Digital to Analog Converter 9. Apple 343S1027 XTA14807AN Bus Transceiver 10. 341S0851 EGRET 11. 341S0851 EGRET | |
| Posted by: ironborn65 on 2022-10-02 14:53:34 @Phipli , I left it there the whole weekend without the battery, .. no way, too bad. The symptoms are: Happy chime, one single high pitch low volume squeaky sound from the speaker after 1 second and then dead silente. the Bt478KPJ66 is warm, like the CPU Pressing the start push buttons shuts it off leaving a while screen pressing the push buttons again doesn't starts it up if I remove one SIM I have the chime of death because it fails the RAM test so I desume the ROMS are fine so does the CPU Looking at bomarcs schematics, the floppy connector is directly connect to: SMD-200 ... what is this? but I do not think it's relevant via PA5 .. what is this? UA1 SWIM UA3 VTG2008-6216 two capacitors C54 C55 two inductors L3 L4  Could a fried SWIM stop the entire boot process and explain my symptoms? thanks you all | |
Posted by: Phipli on 2022-10-02 15:21:26SMD-200 ... what is this? but I do not think it's relevantSMD-200 symbol looks like a varistor? A resistor that changes resistance depending on the voltage. The circuit it is in looks like a filter. Edit : likely for removing excessive voltage spikes? Perhaps... possibly... maybe. | |
| Posted by: jajan547 on 2022-10-02 15:38:47 Can you make a video of what is happening | |
| Posted by: ironborn65 on 2022-10-03 13:00:23 sure, here it is, the sad story continues ... sob I think the UA3 is the fried chip, the culprit is me of course. In this case I'll not be able to replace the VLSI, I successfully replaced an SWIM recently, but this one, it's too much of a challenge thanks for the support | |
| Posted by: ironborn65 on 2022-10-05 05:06:11 the Youtube link above is broken I dunno if a fried SWIM'd affect the booth process in this way any two pence? | |
| Posted by: techknight on 2022-10-17 12:00:59 high pitch sound = hardware failed self-test. Yeh one of your chips died. Probably the SWIM, but there are a couple control signals I think come from elsewhere such as UA3. | |
Posted by: happymacunhappymac on 2022-10-17 14:14:34Hey you're In luck I have a ton iisi chips sitting here.Wow. Do you have FPU and SWIM for a Mac II by any chance? | |
Posted by: mikes-macs on 2022-10-17 14:31:02let's say I was "distracted "and I unplugged and replugged the floppy drive while it was onIf you had left it unplugged, it would have been fine. Replugging it back in while on did the damage. I have IIsi parts also if needed. | |
Posted by: jajan547 on 2022-10-17 17:23:07Wow. Do you have FPU and SWIM for a Mac II by any chance?Just what’s there | |
| Posted by: ironborn65 on 2022-10-19 23:01:08 @techknight thanks. I have a spare SWIM 8942BV / VC2982-0003 from a Mac LC, can I swap it? thanks for following up with this thread | |
Posted by: techknight on 2022-10-21 05:09:16@techknight thanks. Not sure what that particular chip is. try and match the part number. | |
Posted by: mg.man on 2022-10-22 01:10:17I have a spare SWIM 8942BV / VC2982-0003 from a Mac LC, can I swap it?The IIsi SWIM is (Recap-a-Mac photo) part no. 344S0061-A  According to - https://siliconpr0n.org/archive/doku.php?id=mcmaster:apple:344s0061-a - it was used in the Apple II 3.5" disk controller and also the Macintosh Classic. I *might* have one - need to check... | |
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