Asus FX504 not charging battery

[alfredposadas09]

Thanks it was a check to see it was worth to continue or not.

The reason is that I have placed a MOSFET whose source and drain were shorted in PQ21. Since I was working fine before and I thought that there was no problem. But I have read that there is the risk of feeding the CPU with 19V, burning it.

Apart of that, with that defective MOSFET in PQ21 and a good MOSFET in PQ22 my laptop was able to power on.

However now it does not. Since the topic is related with a laptop that can work like a desktop but it does not charge the battery (or the case in which works as laptop but not recognized AC adapter).

What can cause that the laptop doesn't power on?

I have read that the main cause is a failure in power supply, but is there a were to check if more hardware involved in power on process has been damaged?

Thanks

have you try to replace the ec chip? try to replace ec chip

[alfredposadas09]

have you try to replace the ec chip? try to replace ec chip

before replacing the ec chip make sure you have 19v on the current sense ... if you dont have ... try to measure current sense resistor .. make sure the board was removed from the case and every peripherals on it ..

[DavidRM]

have you try to replace the ec chip? try to replace ec chip

Is there a way to check if that ec chip (it is the ITE8987E) is damaged?

How can I check if PCH has been damaged?

[mon2]

No, do not replace ec till we know more about this case. Need to first confirm the battery charge circuit is ok. So far dealing with dead and wounded mosfets with solder shorts on the charger ic.

post pics of the dcin mosfets and this charger ic.

[DavidRM]

No, do not replace ec till we know more about this case. Need to first confirm the battery charge circuit is ok. So far dealing with dead and wounded mosfets with solder shorts on the charger ic.

post pics of the dcin mosfets and this charger ic.

Yes, I will recieve MOSFETs on Wednesday. I know that we have to solve charging issues first.

However I want to know if I can check that PCH and EC are not damaged.

[mon2]

In general - check if there are visual damages to the EC or PCH. If either have very low resistance to ground measurements for their power rails, then yes, it is possible that target or load is shorted.

If you are able to observe some power on led blink pattern, then the EC is probably OK since there is an internal micro running a local firmware that is performing this task. For now, leave these parts alone till we conquer the battery charger circuit to satisfaction.

[linhgemn]

All you have to do is replace this aluminum capacitor. Why? Message me, I will explain.

[alfredposadas09]

Is there a way to check if that ec chip (it is the ITE8987E) is damaged?

How can I check if PCH has been damaged?

pch is not damage for me .. there is a chance in ec damages .. there is a communication between battery and ec and ec between charging ic so better to replace the this ec chip.. i solve a problem of asus x451ma that the battery icon is not detected ( battery pluggedin) but not charging when adapter is removed laptop is not powering off , i change the ec and the laptop works perfectly.. i found out that the sda / scl lines reading was 400ohm .. maybe you can get something on my case to your case

[DavidRM]

No, do not replace ec till we know more about this case. Need to first confirm the battery charge circuit is ok. So far dealing with dead and wounded mosfets with solder shorts on the charger ic.

post pics of the dcin mosfets and this charger ic.

MOSFETs have been replaced but ACDREV does not have proper voltage. VCC and ACDET are OK.

To summarize the overall problem, there is not current in PQ21's gate.

Which is the purpose of PC180 and PC181?

[DavidRM]

I have found this thead in a TI forum. They explain the purpose of both capacitors C_GS and C_GD.

"
C_GD is the capacitance between the gate and drain. This capacitance and the combined total gate capacitance (C_G) must be fully charged for the MOSFET to switch on.

The significance of this is that the charge pump on ACDRV has a limit of 60 uA. By keeping the gate capacitance or gate charge low, you can reduce your turn on time.
"

https://e2e.ti.com/support/power-man...cfet-and-rbfet

In this one it is say that they only control how fast FETs are turned on and the input current but it's omission (and I think malfuction) should not avoid that FETs turn on.

https://e2e.ti.com/support/power-man...tion-questions