HP Envy x360-A Series No display

Model : HP Envy x360-A Series
Board id: DA0Y61MB6E0 Rev: E

Laptop came with shorted and blown up ic PU3 (RT8231BGQW) and PQ9 mosfet. I don't have RT8231BGQW, so i tried to replace with uP1565 ( same IC Pinouts) but not success. No display.

RAM volt is 1.4V, DDR_VTT and DDR_VTTREF have 0.7V, PGood is 3.3V
When i change PR25 to 12K, RAM volt is 1.24V, DDR_VTT and DDR_VTTREF have 0.6V, PGood is 3.3V

Can i used to replace uP1565 for RT8231BGQW?

cygron ha scritto:i tried to replace with uP1565 ( same IC Pinouts)

Hello!
I don't think the pinouts are the same:

As you can see the pin 11 does not match.
On the original RT chip, pin 11 (VID) is the reference voltage setting pin, while on the uP chip, pin 11 (VCC) is the power supply pin.

According to the schematic of your board, the pin 11 of this chip is connected to the 5V power rail via 0Ω resistor. So in case the original RT chip, the VID pin is at high state and this way the feedback reference voltage is set to 0.675V, while the replacement uP chip has a fixed feedback reference voltage of 0.75V and therefore you get inaccurate output voltage.

You can use the chip uP1565 for the replacement, but you have to modify the resistor values in the feedback circuit. For example, you can replace the resistor R24 with a value of 16kΩ and R25 with 20kΩ.
Another thing that I recommend is to add an 1µF decoupling capacitor between pin 11 of this chip and ground.

Difficult to find 16K resistor. Someone from internet forum says APW8868 can replace for RT8231BGQW. I have APW8868B and try to replace. RAM volt is 1.37V, DDR_VTT and DDR_VTTREF have 0.6V, PGood is 3.3V but no display. And i found crack on APU (See in picture). Is APU damage?

cygron ha scritto:And i found crack on APU (See in picture). Is APU damage?

Yes, with such a crack the APU is definitely damaged.