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 Open Source Project Willem Programmer Hardware
 Dual power won't program 27SF512s (anymore)
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rybowen

2 Posts

Posted - 11/07/2005 :  13:47:52  Show Profile  Reply with Quote
My dual power worked flawlessly for the first couple of weeks I've had it, but now it won't erase or program SST 27SF512 chips - even brand new chips, or ones that I programmed with it last week.

The harware checks out with one exception; Pin 1 = Vpp (12.55v), Vcc= 4.98v and the rest are 4.33v.

BUT, Pin 26 is 2.85v.

Is that normal?

It reads and writes 29c256 chips perfectly. I wish I knew what was going on here.
Reply #1

rybowen

2 Posts

Posted - 11/07/2005 :  14:41:06  Show Profile  Reply with Quote
Found the problem:

Broken DIP switch position 7....
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