Replace U8005.
If still the same, probably bad PCH...
If still the same, probably bad PCH...
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820-476-A no fan spin
- Thread starter Fanfwe
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What about U1950 pins?
Oh sorry, I must be tired.
I actually meant U1950.
I did replace U8005 as you suggested, and that didn't help.
Then, since I saw no PM_PCH_PWROK and no PM_PCH_SYS_PWROK on U1950, I removed it and bypassed it with a juper wire to "force" PRWOK signals (since all my power rails actually look good when they pulse. I was kinda thinking that maybe the circuit that checks the power rails is bad, and so the system turns the rails on, sees that PWROK signals don't come up, so system turns all rails off right away, and then tries again 5 seconds later. Is that what would happen if the voltage sensing stuff around Q8150 doesn't work properly ?).
I actually meant U1950.
I did replace U8005 as you suggested, and that didn't help.
Then, since I saw no PM_PCH_PWROK and no PM_PCH_SYS_PWROK on U1950, I removed it and bypassed it with a juper wire to "force" PRWOK signals (since all my power rails actually look good when they pulse. I was kinda thinking that maybe the circuit that checks the power rails is bad, and so the system turns the rails on, sees that PWROK signals don't come up, so system turns all rails off right away, and then tries again 5 seconds later. Is that what would happen if the voltage sensing stuff around Q8150 doesn't work properly ?).
Put back (good) U1950 and post its voltages (or pulses)...
Pin 2 - CPUVR_PGOOD_R: 1.9V
Pin 8 - PP3V42_G3H: 3.42V
All other pins read 0V
With that chip back on the board, instead of the bypass wires, the board doesn't try to start anymore. I have a steady 0.025A current reading on my power supply, no more spikes to 160mA every 5 seconds like I had when I forced the PWROK signals high.
Pin 8 - PP3V42_G3H: 3.42V
All other pins read 0V
With that chip back on the board, instead of the bypass wires, the board doesn't try to start anymore. I have a steady 0.025A current reading on my power supply, no more spikes to 160mA every 5 seconds like I had when I forced the PWROK signals high.
"With that chip back on the board"
Do you mean U8005, or U1950?
No pulse at all at pin 7 of U1950, when you get pulse at PM_SLP_Sx_L signals?
Do you mean U8005, or U1950?
No pulse at all at pin 7 of U1950, when you get pulse at PM_SLP_Sx_L signals?
I mean with U1950 back on the board. (And it's a good one for sure, I have tried it on another board right before)
No, I don't have a pulse on PM_SLP_Sx_L signals anymore. I don't see the board trying to start anymore. It draws 25mA and that's all.
All I have is the G3H and the S5 rails. Other stuff doesn't even pulse.
No, I don't have a pulse on PM_SLP_Sx_L signals anymore. I don't see the board trying to start anymore. It draws 25mA and that's all.
All I have is the G3H and the S5 rails. Other stuff doesn't even pulse.
No pulse for sure when you trigger SMC_ONOFF_L to ground?
If you get pulses w/o U1950, you must get them w/ it too.
Use an o-scope, helps to catch fast pulse.
If you get pulses w/o U1950, you must get them w/ it too.
Use an o-scope, helps to catch fast pulse.