Flakey Toshiba Satellite Pro L500; motherboard LA-4982P rev 1.0, schematic is here (https://www.badcaps.net/forum/attach...7&d=1459525787).
Don't have the right adapter, assume injecting 19V from an HP one is okay?
When I do so, DCin LED (green) lights up; if battery is connected, charging LED (amber) also lights up -- so far so good.
When power button is pressed, power LED (green) briefly lights up and fan starts to spin (for less than 1 second), then immediately shuts down/resets with power LED off again.
Cleared CMOS: disconnected battery and DCin, held power button for 1 minute, no change.
Removed CMOS battery and shorted terminals, no change.
Tried a different CPU and various memory configurations, no change.
Pulled the motherboard out with nothing but fan connected, no change.
Behaviour is almost always reproducible, however I tried reconnecting a new CMOS battery at one point and the LEDs started behaving erratically -- after disconnecting it eventually settled back down into the same pattern again. Not sure what this means.
Checked 'always on' 3.3V and 5V rails seem good.
Looked for shorted mosfets but couldn't find any; there are some suspicious diode mode readings (e.g. PQ30 reads 0.05V in both directions), but I hesitate to conclude anything as they were measured in-circuit.
And here's the flakey part: tried charging the battery for a while -- don't think it is taking any charge, however after doing so the machine actually booted up at one point, and made it into the BIOS before shutting down again...so whatever is wrong can't be *that* wrong.
Any thoughts on what to try most welcome.
Don't have the right adapter, assume injecting 19V from an HP one is okay?
When I do so, DCin LED (green) lights up; if battery is connected, charging LED (amber) also lights up -- so far so good.
When power button is pressed, power LED (green) briefly lights up and fan starts to spin (for less than 1 second), then immediately shuts down/resets with power LED off again.
Cleared CMOS: disconnected battery and DCin, held power button for 1 minute, no change.
Removed CMOS battery and shorted terminals, no change.
Tried a different CPU and various memory configurations, no change.
Pulled the motherboard out with nothing but fan connected, no change.
Behaviour is almost always reproducible, however I tried reconnecting a new CMOS battery at one point and the LEDs started behaving erratically -- after disconnecting it eventually settled back down into the same pattern again. Not sure what this means.
Checked 'always on' 3.3V and 5V rails seem good.
Looked for shorted mosfets but couldn't find any; there are some suspicious diode mode readings (e.g. PQ30 reads 0.05V in both directions), but I hesitate to conclude anything as they were measured in-circuit.
And here's the flakey part: tried charging the battery for a while -- don't think it is taking any charge, however after doing so the machine actually booted up at one point, and made it into the BIOS before shutting down again...so whatever is wrong can't be *that* wrong.
Any thoughts on what to try most welcome.