Hi all,
Another puzzle if you are so inclined. Attached PCB/Schems.
Background:
This unit came to me as "no power". Simple visual inspection revealed a blown up PQB11. I replaced it along with PQB12 just out of standard procedure of replacing them as pairs, and even though it fought me tooth and nail I was able to get a new one in and the board booted fine first try after that.
I've since tested the laptop to boot and even stress tested; no issues whatsoever. However, battery won't charge. It will work off the battery no problems (if I charge it using another laptop/board), but connecting a battery to charge yields a blinking orange light indicating that there's an issue with the charging.
I started diagnosis by measuring the gate on PQB1, which revealed it has an unexpected voltage of 15.3V (same as battery). Measuring on known good board shows ~19V when battery charging. Measured for shorts on gate of PQB1, no shorts. Measured DCIN voltage on PUB1, 19V as expected. Measured drain of PQB1, 19V (same as AC) as expected.
I've since measured (almost) every single voltage and component connected to PUB1, and haven't found anything that stands out or even would explain that abnormal gate voltage. Another kicker: I could only from that point on suspect PUB1 itself, so I got another one from a donor known good board; also the same issue.
I've since also replaced PQB1 and PQB2, to no avail. I'm now officially at a loss and looking for input. Thank you!
Another puzzle if you are so inclined. Attached PCB/Schems.
Background:
This unit came to me as "no power". Simple visual inspection revealed a blown up PQB11. I replaced it along with PQB12 just out of standard procedure of replacing them as pairs, and even though it fought me tooth and nail I was able to get a new one in and the board booted fine first try after that.
I've since tested the laptop to boot and even stress tested; no issues whatsoever. However, battery won't charge. It will work off the battery no problems (if I charge it using another laptop/board), but connecting a battery to charge yields a blinking orange light indicating that there's an issue with the charging.
I started diagnosis by measuring the gate on PQB1, which revealed it has an unexpected voltage of 15.3V (same as battery). Measuring on known good board shows ~19V when battery charging. Measured for shorts on gate of PQB1, no shorts. Measured DCIN voltage on PUB1, 19V as expected. Measured drain of PQB1, 19V (same as AC) as expected.
I've since measured (almost) every single voltage and component connected to PUB1, and haven't found anything that stands out or even would explain that abnormal gate voltage. Another kicker: I could only from that point on suspect PUB1 itself, so I got another one from a donor known good board; also the same issue.
I've since also replaced PQB1 and PQB2, to no avail. I'm now officially at a loss and looking for input. Thank you!
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