HP Pavilion 15-p033tx not switch on

Model : HP Pavilion 15-p033tx
Board id : Y11A DAY11AMB6E0 Rev - E

A few days ago, laptop came power on but no display. Caplocks led blinks one time and continuously. I found CMOS battery is 0V and replaced with good one. And i notice that CMOS battey is drain very fast. When I replaced 3.3V New CMOS battery and a few minutes later it has 2.9V. I found RTC_RST# is about 2.3V (low). I think C367 is leak. So i Remove C367 and laptop run normally. Boot in windows and tested all fine.

After two days, laptop is no display again. Caplocks led blinks one time and continuously again. I try to find the fault but not success. And now laptop cannot switch on. Press power button and no response. Before press power key, Q19 Pin 3 (RTC_RST#) is 2.0V and Pin 2 EC_RTC_RST is 0V. After pressing the power key, Q19 Pin 3 (RTC_RST#) is 2.5V for a second and then 0V. Pin 2 EC_RTC_RST is 3.2V.

I also try to measure the current flows of RTC battery connector using DC Power Supply and Multimeter. Amphere consumption is about 0.030 mAmp. How can i find the fault?

Hello!

Measure the voltage on capacitors C358 and C367 with connected RTC battery only (without connected power supply and main battery).

Voltage on capacitors C358 and C367 with connected RTC battery only - 2.39V

What is the voltage to ground directly on the RTC battery in this case (rail "+3V_RTC_0").

I install 3.3V Battery (New) and measure and rail "+3V_RTC_0". It' show only 2.989. So i directly solder cable type of CMOS Battery and measure the rail "+3V_RTC_0", it's show 3.3V exactly. But battery is also drain and laptop can't switch on. I install 3.3V battery on one night and in the morning i disconnect and measure this battery. It's only show 2.8V.

Check C358, C367, C388.
If necessary, replace them 1uF / 6.3v.

Remove the capacitors C344, C347 and chip U9 from the board. Insert the new RTC battery and check, if it also discharges below 3V overnight.

Remove the chip U9 and now RTC Battery is not discharges any more overnight. Is U9 shorted? Laptop still can't switch on. Need to replace U9?

If the capacitors are not shorted you have to replace U9 (without the laptop it will not work).

I replace U9 and now laptop is power on. But no display and caplocks led blinks one time and continuously. All coils have voltages. Need help.

Have you soldered the capacitor C367 back to the place?

Do you have an oscilloscope?

Does it work on an external monitor?
Measure the voltages on pins 1, 4, 5, 36, 37, 38, 40 of LVDS Conn (CN2).

For matic,
Yes. I try to resoldered the capacitor C367, 358, 388 and also try to replce again U9 with another IC (New) but the same. With 3.0V RTC Battery only, the (RTC_RST) voltage on C367 is about 2.65V. Is that normal?

For Machine,
it does not work on an external monitor.

Make the required measurements on CN2.

Pin 1 - 19.5V
Pin 38 - 3.3V
Pin 37 - 3.3V
Pin 36 - 3.3V

All others pins are 0V

Measure the voltages to ground on both pins of resistors R256, R277 with connected RTC battery only (without power supply and main battery).

Both pins of resistors R256, R277 - 2.6V ( when RTC Battery is 3.3V )

For now, laptop sometimes open and sometimes not open. Fan spin a few second and stop. Power led light on and off.

Measure the voltages to ground on both pins of resistor R302.

Actually there is no R302 and D9 (only solder point). So R302 +3V_RTC_0 side is 3.3V and other side is 0V.

So in this case, the RTC battery should be directly connected to the resistors R256 and R277.
How is it possible that there is only 2.6V on resistors R256 and R277, if they are directly connected to the RTC battery on which the voltage is 3.3V?

cygron ha scritto:Both pins of resistors R256, R277 - 2.6V ( when RTC Battery is 3.3V )