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Well... I'd certainly like to continue with the repair for as long as you are willing to help me with it! But if you think it is time to give up - i will listen.
I am not testing the board with battery, just charger.
Actually yes you are right - 5V_S0 is steady while the fans are spinning.
PPBUS_G3H was measuing 12.25v when you told me it was the GPU before...
Yeah I've tried SMC bypass - it starts with all the fans blazing at full speed straight away, rather than building up, but aside from that nothing else happens. It doesn't switch on properly and none of the voltages change.
Well... It lasted 10 days lol. The laptop has gone back to being totally dead, except the symptoms are consistent now. When turned on, the fans slowly increase in speed until they are at full speed. The laptop then stays in that state, fans at full speed and nothing on screen, no boot chime. No...
Dude... I fixed it!!!
Turns out - they had crushed C8431, which has FB_A0_VREFC on it. I cant imagine why this caused the fault symptoms as it wasn't shorted, it was open. Does that make sense to you?
Yeah - the heat has definitely changed something c ause it doesn't turn off any more. It just spins up to full speed and then stays like that until i cut the power.
Okay, So i have more news on this.
I searched for the dGPU hardware disable mod as you suggested. I found it on the facebook post and I did it, all of it - it was not fun lol.
The board still has the exact same symptoms though! So that suggests that the problem is NOT the GPU. Can you help?
Oh dear... the plot thickens.
After the above, I decided to resolder U8900 again, this time removing it completely from the board and once again replacing all the solder and soldering it back on. The joints looked absolutely perfect and look perfect again now. However, after doing this - the...
"Resolder U8900; use leaded solder. "
I should have mentioned - this was the first thing I did. I've done it and checked it twice.
L8930 Resistance to ground - 26.2ohms
L8960 Resistance to ground - 26.2ohms
1V05_SUS - 1.062v
PP3V3_S4_FET - pulses to 1.7v
PP3V3_S3_FET - pulses to 3v...
I'm not exactly sure what you're looking for when you say big coils. If you're talking about the large inductors on the board...
L2406 - pulses to 0.8v
L7530 - nothing
L7520 - nothing
L7510 - nothing
L7550 - nothing
L7560 - nothing
L8960 - nothing
L8930 - nothing
L9830 - pulse to 0.5v
L7330 -...
Okay! Will remember that for next time - thank you.
PM_SLP_S5_L - pulses to 3.33v and down to 0
PM_SLP_S4_L - pulses to ? around 2v and then down to 0
PM_SLP_S3_L - pulses to ? around 3v and then down to 0
PM_SLP_S3_R_L - pulses to ? around 3.2v and then down to 0
Thanks a lot for your reply.
Board is completely disconnected from everything apart from charger and fans.
No result from SMC Bypass mode.
PPBUS_G3H - 12.25v
3V42_G3H - 3.42v
PP3V3_S5 - 3.33v
PP3V3_SUS - 3.33v
SMC_RESET_L - 3.38v
PM_BATLOW_L - 3.32v
PM_RSMRST_L- 3.30v
PM_PWRBTN_L - 3.41v...