HP 14, LA-A994P, charging light, power led on for 1 second when power button pressed

[ktmmotocross]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

now i see schematic. yes, but still "measure short to ground and voltage when it is starting on all big grey coils and capacitors"

[iplaypty]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

If it is starting, u have 3.3 ALW so u must have EC_ON

measure short to ground and voltage when it is starting on all big grey coils and capacitors

find short to ground, low voltage /overload/, no voltage /not work/ or bigger voltage /burn/


@ in schematic means that is not used

Thank you!

I did test on continuity mode to those caps (attached photos), they beep on both sides.

[ktmmotocross]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

Thank you!

I did test on continuity mode to those caps (attached photos), they beep on both sides.

beep is not short. short is under 4ohm. processor and gpu have low ohms so they beep
how many ohms do u have?

chceck for voltage on all big coils when starting

u have SoC platform, so if something goes wrong, bad is mostly SoC IC

[iplaypty]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

beep is not short. short is under 4ohm.
how many ohms do u have?

So even if it beeps on both sides, both sides have to be less than 4 ohms?

[iplaypty]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

beep is not short. short is under 4ohm. processor and gpu have low ohms so they beep
how many ohms do u have?

chceck for voltage on all big coils when starting

u have SoC platform, so if something goes wrong, bad is mostly SoC IC

Sorry, I am learning a lot from you guys. Thank you!

The ones close to the screen connector are less than 1 ohm on continuity mode, both sides.

[ktmmotocross]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

big coils i mean the big grey cubes.

check voltages on they when u press power button. it must climbing. when not check for short

[iplaypty]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

big coils i mean the big grey cubes.

check voltages on they when u press power button. it must climbing. when not check for short

how?

black lead on ground, red lead on coil +?

[ktmmotocross]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

yes and same for short check

[iplaypty]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

yes and same for short check

PLG1: 10 ohms both sides
PLZ2: 8.7 ohms both sides
PL1002 165 ohms both sides

the rest of the coils are 0L. both sides. no charger plug. no power on.


With charger, no power on:
PL102: 3.0v both sides
PL303: 0v both sides
PL302: 3.6 mV both sides
PLZ2: 0V both sides
PLG1: 0V both sides
PL1002: 0V both sides
PLM2: 0V both sides


When I press power button (what i can see on multimeter)
PL102: 3v both sides
PL303: 3.6v for a split of second
PL302: 5.19v for a split of second
PLZ2: around 100mV
PLG1: around 100mV
PL1002: 1.75v - 1.007 for a split of sec
PLM2: .381v for a split of second

[iplaypty]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

Thank you very much tibd and ktmmotocross.

I was able to fix it.

I injected some amps on JPHW7 and found the bad cap next to UR1.

I removed it and now it turns on and show image on screen.

Is it important to place another cap there as replacement?

Thanks!

[ktmmotocross]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

Thank you very much tibd and ktmmotocross.

I was able to fix it.

I injected some amps on JPHW7 and found the bad cap next to UR1.

I removed it and now it turns on and show image on screen.

Is it important to place another cap there as replacement?

Thanks!

Never start without some component.

Yes replace it.

[ktmmotocross]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

looks like it is on pin 9 of UR1, which is +AVDD12 and thre are two capacitors CR3 and CR4

[tibd]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

Very good, and yes you need to replace that cap. Originally rated for 6.3v in parallel with a 16v cap (CR4). I would change with at least 10v-16 rating. As of capacitance same as original 4.7uf.

[iplaypty]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

looks like it is on pin 9 of UR1, which is +AVDD12 and thre are two capacitors CR3 and CR4

ok, Thank you!

[iplaypty]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

Very good, and yes you need to replace that cap. Originally rated for 6.3v in parallel with a 16v cap (CR4). I would change with at least 10v-16 rating. As of capacitance same as original 4.7uf.

ok, thank you!

[mainah njoroge]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

I have the same problen did u get any solution

[mainah njoroge]

Re: HP 14, LA-A994P, charging light, power led on for 1 second when power button pres

I took some pictures with my phone.

The owner of the laptop told me that he was using the computer, then it suddenly turned off.

Did u manage the laptop because i have the same problem