HP 15 LA-C701P not turning on

[bilalinfotex]

hello friend i ma new here , First, thanks for all your helpful posts .
I have HP 15 LA-C701P motherbord not turn on , no 3.3valw no 5valw .
5/3 ldo are ok
entrep 1 and 2 = 0v
ec_on = 0v
With diode mode maltimetter show 12 with beep (it normal??) on pl8 (5valw coil) .

[Sephir0th]

Re: HP 15 LA-C701P not turning on

Sound like a short to GND. What's the reading in Ohms Mode, low range (200 or sinilar)?

[mcplslg123]

Re: HP 15 LA-C701P not turning on

Did you measured resistance immediately after power plugged in?? If yes, you may get weird value. Allow caps to discharge for some time and then measure again.

[bilalinfotex]

Re: HP 15 LA-C701P not turning on

Sound like a short to GND. What's the reading in Ohms Mode, low range (200 or sinilar)?

Thanks for the answer , there is no short to GND i already inject 5 v .
Please , I want to know how to judge the resistance (what is the normal value and at what point we can say it a short ).

[lapfix]

Re: HP 15 LA-C701P not turning on

Never inject more than 1 volt ! it's a critical you can distroy other component

start by first step :

Voltage at D/G/S of PQ 202 and PQ 203
What's the consumption with/without ram

RTC section :
voltage of JCMOS1 = PCH_RTCRST# and JME1 = PCH_SRTCRST#

[bilalinfotex]

Re: HP 15 LA-C701P not turning on

Did you measured resistance immediately after power plugged in?? If yes, you may get weird value. Allow caps to discharge for some time and then measure again.

Thanks for the answer .
YES i measured resistance immediately after power plugged in and the value keep changing .
tank you for help

[mon2]

Re: HP 15 LA-C701P not turning on

You cannot measure resistance or diode mode if there is power to the logic board !!! Confirm this.

If you have power to the board, remove it and allow some time to discharge the capacitors, then check the resistance without any power. 30 seconds or more is enough to discharge the caps.

[bilalinfotex]

Re: HP 15 LA-C701P not turning on

[QUOTE=lapfix;1185748]Never inject more than 1 volt ! it's a critical you can distroy other component
Thanks for the answer
yes first i inject 1.2 v When I did not find a voltage drop i inject 5 v
Voltage at D/G/S of PQ 202 and PQ 203 are ok 19v / 25v /19 and ACOK is 3v so i tink that charging section is ok .
I dont have power supply to measure consumption with/without ram i am useing old motherboard and take 1.2 v from cpu supply it working with me .
but I will buying one soon .If so, I would like to know how to use consumption in troubleshooting laptop .

[bilalinfotex]

Re: HP 15 LA-C701P not turning on

You cannot measure resistance or diode mode if there is power to the logic board !!! Confirm this.

If you have power to the board, remove it and allow some time to discharge the capacitors, then check the resistance without any power. 30 seconds or more is enough to discharge the caps.

thank you for your help

[bilalinfotex]

Re: HP 15 LA-C701P not turning on

Never inject more than 1 volt ! it's a critical you can distroy other component

start by first step :

Voltage at D/G/S of PQ 202 and PQ 203
What's the consumption with/without ram

RTC section :
voltage of JCMOS1 = PCH_RTCRST# and JME1 = PCH_SRTCRST#

Thanks for the answer
yes first i inject 1.2 v When I did not find a voltage drop i inject 5 v
Voltage at D/G/S of PQ 202 and PQ 203 are ok 19v / 25v /19 and ACOK is 3v so i tink that charging section is ok .
I dont have power supply to measure consumption with/without ram i am useing old motherboard and take 1.2 v from cpu supply it working with me .
but I will buying one soon .If so, I would like to know how to use consumption in troubleshooting laptop .

[mcplslg123]

Re: HP 15 LA-C701P not turning on

You dont answer the questions properly and completely. You dont have a dc supply also. It'll be difficult to proceed further.

Check the basic requirement of SIO and answer these queries:
01.Is dc jack light glowing?
02.Battery charges??
03.Check whether 3V and 5V is generated on coils just after adapter insertion. Voltage should be available on coils for a few seconds only as Deep Sleep Well is involved here.