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[Mac II] SiClone no longer working?

blusnowkitty

Well-known member
I recently picked up an early original Macintosh II which among other things came equipped with a SiClone Si3033 accelerator board. It's a two-part system with what looks to be a mostly passive board that houses the original 68020 and FPU and a second board that contains the 68030 and FPU. The first night I had the Mac II running beautifully; the next night - I went to power it up and I got no boot bong, but the system still booted normally until about 30 minutes later when it had hard locked. I did a quick power cycle and tried bringing it back up but this time I got no boot bong and no display. I could feel the 030 getting warm, but it wasn't actually booting the machine. Pulling the 030 half off the board and just leaving it with the 020 also resulted in the same issue; only when I pulled the 68020 and FPU off the SiClone and stuck them back directly into the II's motherboard could I get it to boot again.

Anyone got any clues as to what could be going on here?

 

Unknown_K

Well-known member
Pictures of the boards would help.  Never heard of that board before but in 1989 it cost $5,000.

 

blusnowkitty

Well-known member
Pictures of the boards would help.  Never heard of that board before but in 1989 it cost $5,000.
Sounds like that's even more reason to get this board back up and running! First picture is of the 68020 half which is currently unpopulated as the 020 and FPU are in the Mac II at the moment. Picture two is of the 030 half. 

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Unknown_K

Well-known member
You need pictures of BOTH sides of each board.

Anyway check the capacitors for shorts and the resisters as well. Any of the chips overheating? Any bad solder joints?

 

blusnowkitty

Well-known member
Far as I can tell nothing is overheating and solder joints are good.

But, the board is littered with tantalums, and we all know how reliable those are...

 
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