Acer Aspire 5 N20C5 - no power, not charging. Motherboard FH5AT LA-K091P

[gfosterCA]

Good afternoon all.

After verifying 19V source and testing for short on the DC charge jack, kept hunting..

Pin 5 of PQB3 shows 19V.
Pin 4 of PQB3 seems to from 0.3V down to 0, and repeat.
Pin 1-3 of PQB3 sit around 0.03V down to 0.

_____

Pins 5+ on PQB4 appear to be shorted to ground.

Voltage injection shows inductor PL501 and PU501 getting hot.

For kicks and giggles, removed the inductor PL501, and short at PQB4 is no longer. Would stand to reason that it's on the side of PU501. Side effect: battery charging is active, and 3.3V present on pin 1 (JKB2 ON/OFFBUTTN#).

PU501 is JW5068C, but I can't seem to locate another in my stack of boards, and can't find a cross-reference for it (yet).

Am I on the right track here, or any other suggestions?

Thanks in advance!

[Sephir0th]

The schematic says that the original plan was to use a SY8288CRAC, which is actually a fairly common 5V controller.
However, the fact that the short circuit disappears as soon as you lift the coil suggests that there is more than just a problem with PU501. The short circuit on the opposite side of PU501 may still be present.

[gfosterCA]

That's a very good point. Just went through my stack of boards and can't find a suitable donor. I've removed PU501, and am only detecting ground on the expected pads. Seems promising at least.

[Sephir0th]

I mean you have the multimeter and the empty pads where the coil is located. You can simply measure resistance to GND of both pads to see what and especially where (controller- or load-side) is something going on.