acer aspire nitro an515-54 missing 3v

[dqtech]

Re: acer aspire nitro an515-54 missing 3v

19V is reaching the IN pins on PU301 ?

What is the resistance to ground of the LDO and 3VALWP ?

If the readings are not low, then PU301 is defective and should be replaced.

When shopping for a replacement (recommend Hong Ming on Aliexpress - they have been good for our past purchases) - be sure to share the full part #. Often the suffix of the part number will define the enable pin logic levels, etc.

yes 19v reach on PU301....reading resistance on LDO and 3VALWP not low...ill try to replace PU301 first

[mon2]

Re: acer aspire nitro an515-54 missing 3v

19V is reaching the IN pins on PU301 ?

What is the resistance to ground of the LDO and 3VALWP ?

If the readings are not low, then PU301 is defective and should be replaced.

When shopping for a replacement (recommend Hong Ming on Aliexpress - they have been good for our past purchases) - be sure to share the full part #. Often the suffix of the part number will define the enable pin logic levels, etc.

[dqtech]

Re: acer aspire nitro an515-54 missing 3v

Which 3v is missing ? Each is based on a local EN (enable pin) -> measure the voltage to ground of these EN pins.

Also, with no power -> meter in resistance mode -> check the resistance to ground of the 3VALWP and also the LDO rail for 3V.

If the resistance is low, the local regulator may be shutting down. Low resistance could mean a shorted cap downstream or some other high current event.

For now, do not consider voltage injection - which must be kept low @ 1 volt or under. This is just in case the CPU rail is shorted to this rail so we do not want to inject a higher voltage.

no 3v on PL301....EN1 (pin 12) read 3.3v and EN2 (pin 11) read 4.35v....ive check resistance on PL301, 3VALWP and LDO reading 0.5v and no short

[mon2]

Re: acer aspire nitro an515-54 missing 3v

Which 3v is missing ? Each is based on a local EN (enable pin) -> measure the voltage to ground of these EN pins.

Also, with no power -> meter in resistance mode -> check the resistance to ground of the 3VALWP and also the LDO rail for 3V.

If the resistance is low, the local regulator may be shutting down. Low resistance could mean a shorted cap downstream or some other high current event.

For now, do not consider voltage injection - which must be kept low @ 1 volt or under. This is just in case the CPU rail is shorted to this rail so we do not want to inject a higher voltage.

[dqtech]

i have an acer nitro 5 with problem no power....ive check on 19v and 5v is normal reading...only missing 3v...here i attach boardview and schematic