Asus M3500QA R2.1 missing 3.3 and 5 volts

[jimmy2022]

Hello. Main power rail and secondary power rail working, but 3.3 and 5 volts is missing. the ec chip has 3.3 volts except that all neighbouring components around ec chip either 0 volts or half volt. tested for shorts can't find anything. i have also included picture of 3.3/5volt chip. there is missing ac detect signal. any help? When pressing power button the 3.3 v drops and then goes back to 3.3 vafter letting go of the button
5 v coil and 3.3 v coil has very high resistance.

[mon2]

Hi. The enable for the always on rails is often created by the main 19v power rail and resistor based voltage dividers or driven by the ec. The ec is often powered by a local rtc / coin cell battery. Is there one on this board? Check and confirm if that rtc battery is depleted. Replace it if cr2032 style which die after a few years. We fixed at least 3 units with replacing only this EC battery.

The always on rails will usually provide a switching leg for the higher currents and also a low current LDO rail. Review the datasheet for these regulators and confirm that the LDO rails are not shorted.

Are they on? Which regulators exactly are onboard for the 3v3 and 5v0 legs?