ACER Predator PH317-51 - No +3VALWP

[Sephir0th]

Hello all,

today i have an ACER, Board Number C5MMH/C7MMH LA-E911P with missing +3VALWP. i found out, it's because of missing 3V_EN Signal.

No history known. Comes from a household resolution. Maybe it lies for a longer time. The Adapter wasn't of correct wattage, so i just replaced it with a original one, but unfortunately nothing changed.

+5VALWP, +3VLP_EC, MAINPWON, EC_ON, EC_RST# and LID_SW# are present. As soon as i press the ON/OFFBTN#, i lost all voltages at EC, except +3VLP_EC. i get the lost voltages back, if i steadily press the ON/OFFBTN#. But if i let go the Button, i lost all voltages again.

Another thing what happens, if i press the Power-Button: The 3V_EN, SPOK_3V, SPOK_3V5V, +3ALWP and +1VALWP comes out just for an blink of an eye.

i checked all Coils, all Pins of PU401 and all Pins of EC (UB1) for short. Nothing found.

What i have done so far (19V missing too at the beginning):

Replaced DC-IN Mosfets PQ303 & PQ304 (Bad looking solder joints)
Reflowed Charging Controller PU301 (bad looking solder joints)
Replaced the 3V Controller PU401 (nothing changed)

Alle tests done with all Subboards and Coin-Cell connected. I have two Switches at the MB (SW2 & SW3). i believe the're only related to battery, is this correct?

Now i suspect the SIO itself defective and want to replace it. Any other suggestions? Thank you for assistance!

[mcplslg123]

Re: ACER Predator PH317-51 - No +3VALWP

3V_EN_R present??

[Sephir0th]

Re: ACER Predator PH317-51 - No +3VALWP

No, unfortunately Not. It's the Same as with 3V_EN. And If you ask: RB14 and RB15 positive checked for correct Resistance. Also checked DB1 and replaced it, Just to be Sure (i forgot to Tell it before). Any Idea?

I did Something crazy and jumpered DB1 for Testing purpose. +3VALVP/+1VALWP Came Up, but still too Low SPOK_3V Signal. I reverted the Changes, because i don't want to mess Up the Board...

[mcplslg123]

Re: ACER Predator PH317-51 - No +3VALWP

Did you removed RB14/15 while jumpering DB1?? If you remove both the resistors, its absolutely safe to jumper db1 for testing purpose.

[Sephir0th]

Re: ACER Predator PH317-51 - No +3VALWP

Erm, no... I wasn't Aware of this being important. if you're confirming, i haven't damaged the EC by this Test, I'll try it again today with removing These Resistors and See what Happens. Otherwise i Just wait for the Programmer arriving. Need it anyway, because i have one more Board Here, which has Problems with the EC.

Greetings

[mcplslg123]

Re: ACER Predator PH317-51 - No +3VALWP

Go ahead and try. I use these sort of tricks to solve a lot of problems without changing the IC. Today i fixed a dell 3542 cedar intel mb-it was not trigerring at all though +3/5VALW was present and all start conditions for sio were met. Bios was also good. Problem was TPS51225 powergood pin was releasing 2.2V instead of 3V. I just cut the track towards IC and jumpered PR4534 so that 3V_5V_POK was released....and it worked like a charm. The same case could've been solved by replacing the IC.

[Sephir0th]

Re: ACER Predator PH317-51 - No +3VALWP

I Tried it, but wasn't able to establish a high SPOK3V Signal. i replaced the EC and Programmed it succesfully after, but nothing changed...

In my despair i measured everything around the EC, Maybe Missing "AC_Present" can be a hint? I reprogrammed the BIOS too, Just to be Sure...

Still nothing. After what i learned so far i never expected to Fail at an 3.3V Coil... But i'm definitely Stuck now...

My next Steps Would be to replace the DCIN-Mosfets again (didn't replaced it with original spares), the Charging IC (Had Trouble with it at the beginning) and the 3V-Controller the Second time. If it wouldn't Change anything i Would start to replace everything on 3V_EN Rail and Maybe on SPOK_3V Rail too.

Howewer, i additionally Hope for a good Suggestions.

The. Charger is original and of correct wattage.

Ty in advance!

[Sephir0th]

Re: ACER Predator PH317-51 - No +3VALWP

I just noticed Someone did some Work at the Charging Connector/Cable before. I was thinking about reversed polarity for a second... But can't be case Here?

[Sephir0th]

Re: ACER Predator PH317-51 - No +3VALWP

Meanwhile amongst other things i replaced the EC and Programmed it succesfully. I additionally flashed BIOS with another dump to Check whether it Changes anything.

But today i Had some Progress while Checking components at 3V_EN Rail. After desoldering RB15 i was able to start the Board.

Now i get the following:

- All voltages present except VCCGT (should be okay because MB has dGPU)
- GPU- and CPU-Controller have PGOOD
- BIOS isn't Posting (CapsLock-Test) and of course No picture
- The Fan Starts for a second, then stops, Board does a Reboot after a few Seconds, again the Fans start/Stop and it stays Like this. No Fans, draws 1 Amps and i have to unplug Power before the heatsing getting too hot.

What i Tried so far:

- flashed original BIOS Back and also an Clean_me version
- Tried another RAM
-- fully Assembled the Laptop to Check whether it Changes anything.

I still suspect the BIOS, so i want to try more dumps and i'll also reflash the EC Just to be Sure.

Howewer any Suggestions are Very welcome. Thank you!

[Sephir0th]

Re: ACER Predator PH317-51 - No +3VALWP

After getting it to work with all voltages present (except VCC_GT), and flashing around 10 BIOS Roms (but still no POST & Picture) i did some additional Measurements while waiting for EC Programmer (long story!) Everything seems fine for me...

LID_SW# 3.265V
EC_VCCST_PG 1.018V
THERMTRIP# 1.017V
H_CPUPWRGD 1.019V

PLT_RST# 3.312V jumping for a few seconds, then stable
PLT_RST_BUF# 3.309V
PLTRST_VGA#_1V8 1.807V
+1.8VSDGPU_AON 1.845V
GC6_FB_EN1V8# 1.843V
GC6_FB_EN3V3 0.000V
1VS DGPU_PG 3.171V
1.35VS_DGPU_PG 3.307V
ALL_GPWRGD 1.808V

except this one here:

VR_HOT# 0.049V

These weird PROCHOT things... howewer, when i desolder RB19, i have 1.020V at VR_HOT# and clarified, the low signal comes from the EC Pin 103 - VCOUT1_PROCHOT ( 0.000V). But i have no idea why i have a LOW there...
Maybe it is related to ADP_I Circuit? Did some measurements there too:

VCIN0_PH 2.831V
VCIN1_ADP_PROCHOT 0.323V
ADP_I 0.950V

PH201 reads in-circuit 22K Ohms instead of 100K Ohms.

Maybe someone can break down this or could this all be meaningless?

[Sephir0th]

Re: ACER Predator PH317-51 - No +3VALWP

I Replaced the EC one more time just to be Sure, but this don't Changed anything in the behaviour.

I additionally noticed the PCH got really warm, so i can't Touch it with the outside of my Fingers for longer as 2 Seconds. Checking voltages there don't give me any hint, except +1.0VALW_MPHY which isn't Coming Out, but resistances is around 50 Ohms, so seems to be normal.

Howewer i suspect more and more an dead PCH. In this Case i should have to give Up on this Point.

I Just want to say thank you for your Patience and your Help on this hard Case.

Kind regards

[Sephir0th]

Re: ACER Predator PH317-51 - No +3VALWP

This thread is almost 5 months old, but i still don't want to give Up on this one...

The Missing +1.0VALW_MPHY wasn't Missing in the end. Just a wrong measurement.

So again i did Spend some time on this Board the Last few days and Had some progress while Measuring and working around on this Board.

I've found a Bad Dual Mosfet ( QK1 ) related to the Touchpad and now the board draws a Bit more Amps and also the Fans staying at full Speed since then.

Additionally i found Out, DDR_DRAMRST# is missing and PM_SLP_S0# really low (~0.4V) but No short there. This is Very weird in my opinion because all voltages and also Signals Like PLT_RST# are present.

Of course i've Tested with Known working RAM.

Maybe Someone can explain why and hopefully has some ideas what to suspect now.

Thanks again!

[SMDFlea]

Re: ACER Predator PH317-51 - No +3VALWP

test voltage and resistance on PU501 pins 5,16,20

[Sephir0th]

Re: ACER Predator PH317-51 - No +3VALWP

Unfortunately everything normal there and Q7 not present if this would be the next question.

After you have pointed for me out where to measure i noticed too, that S0 should be present when VTT is also present (regarding the small table at page 45 lower left. Weird.

Pin 5 - VDDQ - 1.219V - 111 Ohms
Pin 16 - PHASE - 1.219V - 113 Ohms
Pin 20 - VTT - 0.607V 1.2KOhms

So we are back into the direction of bad PCH...? Any ideas left?