Mac IIsi ... I fried it all :(

[ironborn65]

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 $#&%%

 

[joshc]

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?

 

[ironborn65]

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.

 

[imactheknife]

I have a chip possibly from a dead board. Also have a recapped board looking for a home "cough cough"

 

[imactheknife]

try a pram reset?

 

[Phipli]

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.

 

[jajan547]

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

 

[ironborn65]

@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

 

[Phipli]

SMD-200 ... what is this? but I do not think it's relevant
View attachment 47202

SMD-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.

 

[jajan547]

Can you make a video of what is happening

 

[ironborn65]

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

 

[ironborn65]

the Youtube link above is broken

If I were me given the schematics, I'd try to replace the SWIM
I dunno if a fried SWIM'd affect the booth process in this way
any two pence?

 

[techknight]

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.

 

[happymacunhappymac]

Hey you're In luck I have a ton iisi chips sitting here.
View attachment 47180View attachment 47181
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

Wow. Do you have FPU and SWIM for a Mac II by any chance?

 

[mikes-macs]

let's say I was "distracted "and I unplugged and replugged the floppy drive while it was on

If 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.

 

[jajan547]

Wow. Do you have FPU and SWIM for a Mac II by any chance?

Just what’s there

 

[ironborn65]

@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

 

[techknight]

@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

Not sure what that particular chip is. try and match the part number.

 

[mg.man]

I 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...