820-00165 sometimes quarter fan spin

[ielectron]

dont see any water damaged, but anyway i cleaned it properly

first it did not have any voltages, not even 3.4V, after taking it apart and just testing it on the table now it has green light, 3.4V, 8.59V, 3.3V

most of the time fan wont spin, but sometimes it goes in a loop, fan spins a bit, stops, spins a bit and so on

replaced: u1950, u7100, u7501

r7121 r7122 are ok, 10 ohm, connecting to the chip

c1910 have 3.3v on pin1

 

[2informaticos]

"replaced: u1950, u7100, u7501"
What measurments made you changed them?

Any pulse at ALL_SYS_PWRGD and VCORE?
Did you try SMC bypass mode?

 

[ielectron]

PPVCC_S0_CPU jumps up to 1.8v, and a second later again, then nothing, on L7320 i measure 16ohm without removing the coil

ALL_SYS_PWRGD jumps to3.3V, then 3 seconds later again, then dies

in smc bypass mode at least the fan spins twice, but the measured voltages are the same

 

[ielectron]

PM_SLP_S4_L does the same, 3.3V volt, jumos up twice then dies

 

[2informaticos]

Check for pulse at pin 3 of u1950 and PLT_RESET_L.

 

[ielectron]

they are doing the same as well

jump to 3.3 twice then zero

 

[2informaticos]

Check all SPI Bus Series Termination resistors and their traces.

 

[ielectron]

all the resistor ar ok, traces are not damaged, no water damage at all

i put a new bios chip on it from another 00165 board, as far is a know at least it should power on with other bios chip, but this does the same thing, voltages come up 2x then dies

 

[2informaticos]

So you get two pulses when charger is connected?
Low chances to solve it.
Change SMC, just in case.