HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pres

[MobileXT]

I have a friend of mine that he gave me a HP-15 to repair. I didn't try fix any PC before but I did fixed a lot of macbook computer. That being said i'm a new to fix PC laptop. I don't even know where I start. The Mother board Parts number is ZS050 LA-A994P REV.2 2014-03-13. anyone can assist me I would greatly appreciate.

Thanks,
MobileXt

[MobileXT]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

Okay, I took some pictures where I did the measurement. I don't have schematic on this Version 2 I do have the version 1 but I'm not sure if that is the correct one. Please see attached photo and need some advice.

[Sephir0th]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

What is the actual issue/behaviour of the Laptop? Please Tell us detailed as possible. However, 19V Rail seems fine. Share shematic Please and/or ask for Rev. 2 in Schematics Section. We have to inspect 3.3V and 5V.

[MobileXT]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

The actual issue is just don't turn on. The WIFI LED turn and CAPS lock ket when power button press. I don't have Voltage on the 3VALWP and 5VALWP using Schematic Ver. 1

[MobileXT]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

At PU301 pin 13 EC_ON voltage is present and PIN 11 also present 19v. It could be PU301 DEAD?


Note I'm using LA-A994P Ver1 Schematic for now until i have the Ver.2

[sopik78]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

Have you measured all power rails for short yet? If not, do it first. While you don't have 19V after second DC-in mosfet, there must be some issue.
As far as I know these boards, I guess there could be shorted CPU. But do your own measurements.

Edit: my mistake, PQ103 has 19V on both sides and 3V is for PQ104, which is correct.

[MobileXT]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

There's no shorted on the board

[sopik78]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

+3VL generated? BIOS IC has VIN power?

[MobileXT]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

I Will try measure this one I will report back . Also on PD2 I have 19V and 0.7V on the other PIN please see attached.

[MobileXT]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

+3VL generated? BIOS IC has VIN power?

Both BIOS IC have 1.8V and +3VL is also present

[sopik78]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

Both? I think there is only one 8MB SPI. Try to reflash BIOS, also EC.

[Sephir0th]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

The actual issue is just don't turn on. The WIFI LED turn and CAPS lock ket when power button press. I don't have Voltage on the 3VALWP and 5VALWP using Schematic Ver. 1

I asked you to Share your actual Schematics and of course, I Understand you're working With Revision 1 and suggested you to ask in Schematics Section for Rev. 2 and i Just saw you have opened a Thread there. Very good.

However, Better and faster Help Only possible with Schematics. Please Share it.

[MobileXT]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

Here is the LA-A994P Rev1 Schematic

[MOD EDIT] Link to schematic -> https://www.badcaps.net/forum/troubl...hematic-needed

[Sephir0th]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

Share exact voltages of PU301 Pin 6,9,11,12,13,14,15,17 and measure Resistance to ground on PIN 9 and 17 with all Power removed.

Edit: 0.7V ADP_ID seems a little Bit Low, i think should be around 3 - 4V, but unfortunately i'm Not really experienced in HP devices. So can be meaningless, because you're getting EC_ON Signal, AS you Said before.
EDIT2: i have Just researched a Bit and believe 0.7V is okay.

[MobileXT]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

Share exact voltages of PU301 Pin 6,9,11,12,13,14,15,17 and measure Resistance to ground on PIN 9 and 17 with all Power removed.

Edit: 0.7V ADP_ID seems a little Bit Low, i think should be around 3 - 4V, but unfortunately i'm Not really experienced in HP devices. So can be meaningless, because you're getting EC_ON Signal, AS you Said before.
EDIT2: i have Just researched a Bit and believe 0.7V is okay.

PU301 diode Mode (Red on Ground)
Pin 6= 0.522v
Pin 9=0.337v
Pin 11=0.467v
Pin 12=0.677v
Pin 13=0.525v
Pin 14=0.532v
Pin 15=0.459v
Pin 16=0.433v
PIN 17= 0.400V

PU301 Resistance to Ground (Black on Ground)
Pin 6= 26.20kΩ
Pin 9=16.45KΩ
Pin 11=23.40MΩ
Pin 12=99.0kΩ
Pin 13=O.LMΩ
Pin 14=265.5KΩ
Pin 15=47.8KΩ
Pin 16=26.20 kΩ
Pin 17 = 29.75KΩ

[MobileXT]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

Both? I think there is only one 8MB SPI. Try to reflash BIOS, also EC.

I need to figure it out first on the PU301 why is not turning on. EC_ON is present and 19V VIN is present. Once I get this Power rail Running then I will go ahead on the BIOS Reflash.

[Sephir0th]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

PU301 diode Mode (Red on Ground)
Pin 6= 0.522v
Pin 9=0.337v
Pin 11=0.467v
Pin 12=0.677v
Pin 13=0.525v
Pin 14=0.532v
Pin 15=0.459v
Pin 16=0.433v
PIN 17= 0.400V

PU301 Resistance to Ground (Black on Ground)
Pin 6= 26.20kΩ
Pin 9=16.45KΩ
Pin 11=23.40MΩ
Pin 12=99.0kΩ
Pin 13=O.LMΩ
Pin 14=265.5KΩ
Pin 15=47.8KΩ
Pin 16=26.20 kΩ
Pin 17 = 29.75KΩ

Mhm, i don't know whether it is my "bad" english or not, but i wanted to ask you to share the voltages when Adapter is plugged (DC-Mode, Red Probe on PinX and Black Probe on Ground). But the resistances are looking fine.

[MobileXT]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

PU301 POWER Adapter Plug-in Voltage Measurements.

Pin 6= 3.42v
Pin 9=3.43v
Pin 11=20v
Pin 12=3.324v
Pin 13=3.302v
Pin 14=5v
Pin 15=3.3v
Pin 16=3.3v
Pin 17 =5.21v

[mcplslg123]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

All the reading seems good but still you dont have 3Valwp/5valwp. You need to check entrip1/2 and fb(feedback) pins as these two signals decide whether you will have output on coils or not. Bios corruption is a possibility-so do flash bios first.

[Sephir0th]

Re: HP ZS050 LA-A994P, charging light, power led on for 1 second when power button pr

All the reading seems good but still you dont have 3Valwp/5valwp. You need to check entrip1/2 and fb(feedback) pins as these two signals decide whether you will have output on coils or not. Bios corruption is a possibility-so do flash bios first.

Sorry for interposing a bit, but would you explain this for me, please. I'm actually asking myself how it can be a BIOS issue, if the SPI not getting its +1.8VALW on Pin8 in this Case? Actually I have a similar case (5VALW present, but no 3VALW, SY8286BRAC, known for often failing) and if this is true, maybe there is a chance to bring it back to life by simply flashing the BIOS. I just want to understand this behaviour, if this is true.

Greetings