help da0x36mbae0 rev e does not turn on

[marcelofct]

I have this motherboard that I turn on and the ic L8 = xx heats up
what are the 3.3v
I press the power button and it does not heat it turns off and heats
change the IC twice and the same thing happens
the USB-C ammeter indicates
19.9v
0.080 and 0.180a
3.3 watts
I attach images please I need your help

LINK IC L8=XX

https://cdn.badcaps-static.com/pdfs/...b416ded7d7.pdf

[Sephir0th]

Re: help da0x36mbae0 rev e does not turn on

What is the question? When Inputs and Enable are fine you need to check the load side.

Resistance to GND at LDO3 and LX?

[marcelofct]

Re: help da0x36mbae0 rev e does not turn on

What is the question? When Inputs and Enable are fine you need to check the load side.

Resistance to GND at LDO3 and LX?

thanks for your help


Resistance to GND at LX =8.7 k
Resistance to GND at LDO3 = 2K

[marcelofct]

Re: help da0x36mbae0 rev e does not turn on

help

[mon2]

Re: help da0x36mbae0 rev e does not turn on

These are high resistance readings, there is no short on these measured rails.

[Sephir0th]

Re: help da0x36mbae0 rev e does not turn on

Could be still something after a load switch. Not the first time I would challenge this. Need experience to find the possible culprit or even better with help boardview/schematics. Unfortunately it seems, there is nothing available.

[Udemzy]

Re: help da0x36mbae0 rev e does not turn on

Check impedance of bios pin 8, check LDO impedance, check coil impedance.

Theres a possibility that SIO ,PCH or IC is short.

[marcelofct]

Re: help da0x36mbae0 rev e does not turn on

sorry, I had personal problems and the laptop is no longer available for repair

[IDislikemakingLogins]

Re: help da0x36mbae0 rev e does not turn on

just had one with the same fault. With the one i got the short was a cap that bridged the 3.3v and the 3.3vldo togther at the tas2557 ti 8ba6971 mono amp by the pwr connector. found by injecting 3.3v at 300ma n the ldo. cheep thermal imager and iso ftw.

[treboRRRR]

Re: help da0x36mbae0 rev e does not turn on

found by injecting 3.3v at 300ma n the ldo.

sorry for dumb question, please elaborate what you mean by "n the ldo" ?

have the same issue at hand, customer installed battery connector upside down, and now the board sometimes charges until you shut down the machine. So it resets the cycle and i think the charging chain is too hot to start charging again, so the orange charging led blinks and laptop doesn't power on, untill i disconnect the battery and wait a while. Same IC L8_XX heats up and changing doesn't help, still heats up.

[mon2]

Re: help da0x36mbae0 rev e does not turn on

"n the ldo"

I think the op meant "on the ldo".

LDO = low drop out regulator. Takes in a higher input voltage and will lower (burn) the input voltage value to a lower one. Often, LDO will be supporting a relatively close input to output range since the burn off effect = heat.