Asus X45U on off repeatly helpp

[dokterpc]

Hi, anyone ever get this problem on asus x45u rev 2.1, this mb (motheboard) get on when plug in charger and 3-5 second get off and then on again just always like that continous. Please help me thankss

[mon2]

Re: Asus X45U on off repeatly helpp

Is it stable with using only a charged battery?

Do you see video when it is on ?

[dokterpc]

Re: Asus X45U on off repeatly helpp

Is it stable with using only a charged battery?

Do you see video when it is on ?

This

[dokterpc]

Re: Asus X45U on off repeatly helpp

Is it stable with using only a charged battery?

Do you see video when it is on ?

This battery is not function, i will search first the new for try with only battery

[dokterpc]

Re: Asus X45U on off repeatly helpp

I have test with battery only when i push the power button it can on just 3 second and then the power off

[mon2]

Re: Asus X45U on off repeatly helpp

What are voltage readings on each pin of the battery connector?

Locate the battery connector and there will be nearby mosfets for:

Battery mosfet that will turn on during battery only mode.
High and low side mosfets to charge the battery pack using the 19v external power adapter feed.

What charger IC is on your board? Likely the TI 'BQ' charger series? Share the full markings of this IC for a review.

[mcplslg123]

Re: Asus X45U on off repeatly helpp

Does it make sense to probe charging circuit when battery is being charged/discharged perfectly? What rails are coming up during the brief interval when it turns on-should be the focus area.

[rediii]

Re: Asus X45U on off repeatly helpp

do you have a thermal camera? check, if something gets hot rapidly. it could mean anything: bad i/o-chip, broken bios, bad pwm controller, bad cpu/gpu, short on sub rail, logic failures and so on... take a look at all important rails, like mcplslg123 said, especially pwrgood and enable pins.

boardview attached, you need open board view and the fz-key

[rediii]

Re: Asus X45U on off repeatly helpp

aaand: check the power button

[mon2]

Re: Asus X45U on off repeatly helpp

Does it make sense to probe charging circuit when battery is being charged/discharged perfectly?

From the OP's post # 4 & #5, feedback is that the battery use is also not functional. We do not know yet if the battery is charging or discharging.

From the details of the charger IC markings we will have a better idea of which logic is onboard since the schematic is in the witness protection program. Common to Asus.

The charger is most likely the BenchmarQ (TI) series but do post the top side markings / pics. Then we can review against reference datasheets or other schematics that feature this controller.

Update:

1) Found the repair guide and assorted BV files for this logic board.

2) The charger IC onboard is the BQ24725. Datasheet is attached.

The logic board will have a similar schematic to the one that is attached.

So this logic board will be fitted with 2 x DCin N-channel mosfets; high & low side battery charge N-channel mosfets; battery pass-through mosfets.

Which version is your logic board ?

[dokterpc]

Re: Asus X45U on off repeatly helpp

My version logic board is x45u rev 2.1, yeah ic charger is bq725,
With charger only pin :
1-2 : batcon is 1,06v
3-4 gnd
5-6 smb1 clk & data : 3,28v
7 bat_in# 3,18v

[dokterpc]

Re: Asus X45U on off repeatly helpp

With charger only mb is on with 0.34a in 5 seconds and off and on again always like that

[dokterpc]

Re: Asus X45U on off repeatly helpp

I also check every inductor all present except vcore is 0v and +12vsus is 13,85v