I have been following the current thread with growing gloom...I have a 520 that came with two power supplies...one utterly dead, and one that powers the machine for about 40 seconds, just about through a no-extensions boot of 7.6, then cuts off. Pull the AC off, replace the cord, and it is good for another 25-35 seconds. Each retry is a little shorter. I get the same whether the (shot) battery is in or not. It looks like it runs fine other than this.
Anybody know what might be doing that? Some sort of thermal breaker?? I have the totally dead one about half chopped apart, and if I know where to look I might be able to fix or work around the problem.
More than likely it's a thermal shutdown circuit in a voltage regulator. The problem is this chip might be 90% of the circuitry and it may be an unusual chip that's hard to find. Oh and it might also be hard to remove.
Try using a cooling spray on the circuit to see if it will keep the power supply working. If it does then carefully try applying spray to individual parts. You can get cooling spray at electronics shops or Radio Shack.
Failing that, does anyone know which prongs in the machine end of the plug run the machine, and which charge the battery?? I may get desparate enough to whip together a run-only PS using the cord of the utterly dead one. It won't be pretty, but it'll work. And finally, is that confirmed 16 volts to run? Thanks for any information you can give!! Don Bowers, [EMAIL PROTECTED]
Looking at the connector with the notch down:
Upper Left - Battery power Upper Right - Computer power Lower Right - Ground Lower Left - Ground Sense
Both power supplies are spec'ed at 16.4-16.6V
On the supply that briefly works you might try swapping the battery and computer power, the battery circuit might be working fine and will power the computer.
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