Toshiba A135 Laptop
Symptoms:
Starts, but will not post. Both the Hard Drive and Optical Drive lights remain on, but no action on either. Battery will charge and will also exhibit same as above on AC power with Battery removed. The cooling fan runs and the CPU gradually gets hot.
Found one of the Power Rails with NO voltage at the output of its associated inductor. It is the rail being driven from an ISL6269ACRZ Controller, which in turn drives the Mosfets (a 4800 and 6690AS). I'm not sure what the voltage should be, nor what this rail feeds – could be 1.05 volts, but has to be between .6v and 3.3v as that's the ISL6269ACRZ spec. The rail measures 22 ohms to from inductor to ground, with the feed side of inductor disconnected from the Mosfets.
Don't know if I should look for a short in the output or troubleshoot the Power rail Control Circuit.
Any ideas would be appreciated.
Thanks
Symptoms:
Starts, but will not post. Both the Hard Drive and Optical Drive lights remain on, but no action on either. Battery will charge and will also exhibit same as above on AC power with Battery removed. The cooling fan runs and the CPU gradually gets hot.
Found one of the Power Rails with NO voltage at the output of its associated inductor. It is the rail being driven from an ISL6269ACRZ Controller, which in turn drives the Mosfets (a 4800 and 6690AS). I'm not sure what the voltage should be, nor what this rail feeds – could be 1.05 volts, but has to be between .6v and 3.3v as that's the ISL6269ACRZ spec. The rail measures 22 ohms to from inductor to ground, with the feed side of inductor disconnected from the Mosfets.
Don't know if I should look for a short in the output or troubleshoot the Power rail Control Circuit.
Any ideas would be appreciated.
Thanks
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