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Blew up my IIsi board...recoverable?

Von

Well-known member
It is with great shame and embarrassment that I submit this post.  I was working to get my 2nd soft power transistor build and when I went to test, I forgot that the power supply was still plugged into the IIsi motherboard. When I flipped the power strip on there was a pop and then that smell...

Here is the board:

2018-11-24_14_57_52.jpg

And here is what literally blew up:

2018-11-24 14.58.35.jpg

My walk of shame explaining this begins now.  The board was on the bench and plugged in to the SeaSonic power supply with all wires except for pins 9 and 10 (+5v_SB)...these were floating freely on the bench.  I believe pin 9's wire connects the soft power transistor such that when the keyboard power on or the power button is pushed.  I thought the power supply was only connected to a spinning drive so I could see if the soft power transistor work.  What happened was the wire connected to pin 9 was lying across the open SeaSonic chassis and its metal end shorted on something when the PS was powered on.

This appears to be the extent of the visible damage.  Did I kill me IIsi or is this something that could possibly be fixed?

 

Franklinstein

Well-known member
You blew up the CUDA chip. No recovery from that without a new chip, and these are not off-the-shelf parts; you need to get one from a donor board. You'll want to remove the old chip and do some checks to see if there's further damage, but if not, it should be recoverable with a new chip and probably some discrete components (resistors, capacitors, whatever may be dead).

 

Von

Well-known member
I googled the visible part number and got no hits so a donor board it is...

Mods, could you please move this to the Mac II forum...thx

 
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