Acer Aspire E5-575 Mosfet

[spike3333]

I have a Acer Aspire E5-575 that died. The power supply checked out. When the power supply was plugged in, the board was getting voltage but neither the battery charging light or the power light came on. I removed the first Mosfet (PQ22) and AON6414AL and jumped it and both lights came on and the laptop started normally. I assumed that it was a bad Mosfet and ordered one. After soldering in the new Mosfet, I get no lights again. I attached the circuit for reference. I am not an EE, so I was not able to do any more troubleshooting. Any suggestions on the next steps would be appreciated. Thanks

[mon2]

Re: Acer Aspire E5-575 Mosfet

With extreme care, measure the voltage on each pin of the charger IC @ PU5. Post your measurements.

[Duranitron]

Re: Acer Aspire E5-575 Mosfet

I have a Acer Aspire E5-575 that died. The power supply checked out. When the power supply was plugged in, the board was getting voltage but neither the battery charging light or the power light came on. I removed the first Mosfet (PQ22) and AON6414AL and jumped it and both lights came on and the laptop started normally. I assumed that it was a bad Mosfet and ordered one. After soldering in the new Mosfet, I get no lights again. I attached the circuit for reference. I am not an EE, so I was not able to do any more troubleshooting. Any suggestions on the next steps would be appreciated. Thanks

Measure the vcc of pu5.

[piernov]

Re: Acer Aspire E5-575 Mosfet

https://www.badcaps.net/forum/showpo...02&postcount=2
https://www.badcaps.net/forum/showthread.php?t=90356

[spike3333]

Re: Acer Aspire E5-575 Mosfet

Can you list which pins you want me to post voltage readings of please

[mon2]

Re: Acer Aspire E5-575 Mosfet

Regn
acok
acdet
acdrv
vcc

[spike3333]

Re: Acer Aspire E5-575 Mosfet

Is it safe to test this with the Mosfet jumped or should I remove the jump and put back in the new Mosfet I purchased?

[mon2]

Re: Acer Aspire E5-575 Mosfet

Wait till you have the proper mosfets install onboard. Never jump anything till more is known about the logic board.

Wish to confirm if the charger is able to see the conditions to enable the internal charge pump to boost the voltage from REGN (~6 volts) to drive the 2 x DCin N-channel mosfets.

[spike3333]

Re: Acer Aspire E5-575 Mosfet

I had to remove the PCB to get to this IC. Should I attach the battery for these measurements?

[spike3333]

Re: Acer Aspire E5-575 Mosfet

ACDRV ~4V
VCC 19V
ACDET 2.6 V
ACOK 0 V
REGN 6 V

Same with or without battery

[mon2]

Re: Acer Aspire E5-575 Mosfet

ACDRV is too low. It should be ~25v for the gate pin on a normal system (19v + REGN voltage of 6v = ~25v).

Locate and remove the 4k resistor that is in series @ PR165. Do not lose this part.

Then power up again and measure the ACDRV voltage at the charger IC.

[spike3333]

Re: Acer Aspire E5-575 Mosfet

With the resistor removed and the trace open the measurement at pin 4 (ACDR) is in the microvolts

[mon2]

Re: Acer Aspire E5-575 Mosfet

with no power, confirm the operation of PQ22 mosfet by checking the resistance values. If you see '1' or 'OL' on the meter -> switch to a higher resistance scale.

Measure the resistance as follows:

Source (1-2-3) & drain (5-6-7-8)
Source (1-2-3) & gate (4)
Gate (4) & drain (5-6-7-8)

Post each measurement and the meter scale used.

[spike3333]

Re: Acer Aspire E5-575 Mosfet

Should I replace the 4k resistor first

[mon2]

Re: Acer Aspire E5-575 Mosfet

No, not for these resistance checks.

[spike3333]

Re: Acer Aspire E5-575 Mosfet

The only reading I get is .95 Mohm across source and drain. All the others are OL. It's a cheap mutimeter that states it will read from 400 ohm to 40 Mohm with 1 percent accuracy.

What should the readings be?

[spike3333]

Re: Acer Aspire E5-575 Mosfet

Just wondering if the readings indicate that the laptop is beyond repair or if anything more can be done, thanks

No, not for these resistance checks.

[Sephir0th]

Re: Acer Aspire E5-575 Mosfet

Issues in DC-IN circuitry usually should be repairable. Especially since you stated it is working when you jumper the MOSFETs, which btw was a very dangerous task in case you have a Main Power retail shorted to any High-Side or even to GND.

So you probably have "just" something wrong around the charging controller, where was already asked for some measurements. You should measure resistance to GND of any pin without power to check for unexpected shorts and even better all pins present voltages. Be careful to not short any pins together while doing so.

[spike3333]

Re: Acer Aspire E5-575 Mosfet

Issues in DC-IN circuitry usually should be repairable. Especially since you stated it is working when you jumper the MOSFETs, which btw was a very dangerous task in case you have a Main Power retail shorted to any High-Side or even to GND.

So you probably have "just" something wrong around the charging controller, where was already asked for some measurements. You should measure resistance to GND of any pin without power to check for unexpected shorts and even better all pins present voltages. Be careful to not short any pins together while doing so.

So resistance measurements on PU5, test all pins to GND with and without power applied to MB, testing for shorts only, is that correct?