R40 Plus - Power problem, won't switch on

Hi,
my sister in law has an R40 Plus, bought early 2008.
She uses it almost constantly on external power, and the cable in the moulded power plug has twisted and developed an intermittent short.

That's an easy repair, but she only told me after the thing had stopped working and now the machine will now not turn on.

When connecting either the battery or the DC adapter (whichever first), the power light flicks as the board powers up, but beyond that the power light does not come on and the machine will not run.

I have a schematic for it and have traced through the power input stages from both the DC input and battery - everything seems OK, which is a shame, I was hoping it was a component near the power input.

I've tried disconnecting the cmos battery overnight with no effect.

I'm an electronics designer by profession, but I don't have gear to work on fine pitch surface mount, and most of the descrete parts have no component IDs so detailed circuit tracing is rather difficult.

Any ideas, or is it time for a new board or machine?

 

1. Did you try using the mains adaptor with the battery removed from the computer?

2. Try removing and replacing the RAM, one module at a time. A poor RAM connection can give the symptoms you describe.

John

 

Hi,
thanks for the reply.

I have borrowed a good battery, and found that with that the machine is working - it must be something in the charger input side causing the problem.

I will have to trace through the input circuit again when I get chance.