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Classic II not holding PRAM data

GuyWithGuitars

New member
I have a nearly immaculate Classic II, which I recapped for sound. (the issue was there before the recap, BTW)

I have 3 new, fresh 3.6v PRAM batteries, which were installed to test on 4 other classic Macs, and tested for voltage and work fine on my LC's, IIci's and SE/30. Definitely no battery problems. From what I can see, logic board is clean. No leaky battery goo, no leaky cap goo that ate through any traces, etc. Again, VERY clean. I tested continuity at the logic boards' battery holder both at the holder clips and at the solder pads on the bottom of the logic board. Again, shows 3.6-3.7v.

Still, the little Mac refuses to hold date/time, mouse settings, etc. PRAM reset as well.

Wondering of there is one component (the EPROM itself perhaps) that I'm overlooking.

Any ideas would be appreciated.

 

James1095

Well-known member
Find the SRAM chip that stores the data and measure the voltage at the power pins with the machine unplugged. You should see >3V from the battery between the power pin and ground of the IC. It's possible the IC is bad, but I would first suspect a connection or the diode that isolates the battery from the power rail.

 
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