Asus GL503VD Not charging or powering on

[Jasonexe]

Hi, anyone that could help me? My asus GL503VD Suddenly turned off one day. My laptop doesn't turn on, when i try to turn it on with the charger plugged in nothing happens. Also the led indicators don't light up. I tried disconnecting the battery and plug the charger in and same issue persists. I noticed that the motherboard makes a small clicking sound when the charger is plugged in but that's it.. i got the tools to measure resistance etc.. so if anyone could help it would be really appreciated.

[mon2]

Asus GL503VD Not charging or powering on

Hi. Start with the dcin connector.

Meter in DC 30v or higher setting.

Measure the voltage to ground of DCin connector. You should have ~19v. Confirm it.

Red meter probe at the dcin connector; black to ground - shield is ok.

Them locate the 8 pin mosfets that will follow. Mosfets are electronic switches that must enable to power the logic board.

Post the topside markings of these mosfets. Great if you can post pics of the area.

Often, the 2nd dcin mosfet gets damaged. To be determined.

[Jasonexe]

Re: Asus GL503V does not power on battery

I measured the voltage when i plug the charger in and I’m getting 0.44V.

the Mosfets that are used are the TPCA 8059-H.

[mon2]

Re: Asus GL503VD Not charging or powering on

These are N-channel mosfets so the GATE pin has to be higher than the voltage being passed between source / drain pins.

Measure the voltage to ground of each pin of each mosfet.

source (1-2-3)
gate (4)
drain (5-6-7-8)

https://www.arrow.com/en/products/tp...hl1q-m/toshiba

Continue to review the logic board for the battery charger IC on this board. The gate pins of these mosfets is being driven by the charger IC. It is possible that the charger IC is the 'BQ' series from TI.

[Jasonexe]

Re: Asus GL503VD Not charging or powering on

These are N-channel mosfets so the GATE pin has to be higher than the voltage being passed between source / drain pins.

Measure the voltage to ground of each pin of each mosfet.

source (1-2-3)
gate (4)
drain (5-6-7-8)

https://www.arrow.com/en/products/tp...hl1q-m/toshiba

Continue to review the logic board for the battery charger IC on this board. The gate pins of these mosfets is being driven by the charger IC. It is possible that the charger IC is the 'BQ' series from TI.

Okay, this are the voltages i got.

Left Mosfet:
Source: 0.37v
Gate: 0.37v
Drain: 0.00v

Right Mosfet:
Source: 0.37v
Gate: 0.37v
Drain: 0.37v

I forgot to mention that the battery charger IC the BQ24780S

[Stevedb]

Re: Asus GL503VD Not charging or powering on

I do not think that are the in rush mosfet the first and second mosfet the red corner. I think they are on the otherside of the board
.

[mon2]

Re: Asus GL503VD Not charging or powering on

Ditto. Locate the DCin power adapter connector and then locate the mosfets close to the charger IC.

If there is a fuse, check if the fuse is receiving power from the adapter.

These mosfets are not being powered.

[Jasonexe]

Re: Asus GL503VD Not charging or powering on

Ditto. Locate the DCin power adapter connector and then locate the mosfets close to the charger IC.

If there is a fuse, check if the fuse is receiving power from the adapter.

These mosfets are not being powered.

I checked the fuse close to the dc jack connector and im getting 0.40v. I also checked the fuse close to the battery charger ic and i get no voltage reading. I also noticed that the laptop charger outputs 0.40v once i plug it in the motherboard. When i plug it out the voltage stays the same. The only way to make it output 19.7 volts again is by replugging it in the wall socket. I got 2 adapters so im sure that my adapter is not the problem.

[Vesko356]

Re: Asus GL503VD Not charging or powering on

I checked the fuse close to the dc jack connector and im getting 0.40v. I also checked the fuse close to the battery charger ic and i get no voltage reading. I also noticed that the laptop charger outputs 0.40v once i plug it in the motherboard. When i plug it out the voltage stays the same. The only way to make it output 19.7 volts again is by replugging it in the wall socket. I got 2 adapters so im sure that my adapter is not the problem.

Obviously you have a shorted main power line then, check the resistance to ground at that line.

[Jasonexe]

Re: Asus GL503VD Not charging or powering on

Obviously you have a shorted main power line then, check the resistance to ground at that line.

I checked the resistance and i’m getting 41.5K Ohms when i measure the positive and negative pin from the motherboard dc jack.

[Vesko356]

Re: Asus GL503VD Not charging or powering on

I checked the resistance and i'm getting 41.5K Ohms when i measure the positive and negative pin from the motherboard dc jack.

DC in jack is before the first two mosfets, measure the resistance after the mosfets. The short is after the mosfets!

[Jasonexe]

Re: Asus GL503VD Not charging or powering on

DC in jack is before the first two mosfets, measure the resistance after the mosfets. The short is after the mosfets!

Okay, I measured both mosfets. I set my multimeter to 200K for measuring resistance. This are the measurements i got.

Left Mosfet:

Pin 1-2-3 (Source): 52.8K Ohms
Pin 4 (Gate): 52.8K Ohms
Pin 5-6-7-8 (Drain): 0.6 Ohms

Right Mosfet:
Pin 1-2-3 (Source): 52.8K Ohms
Pin 4 (Gate): 52.8K Ohms
Pin 5-6-7-8 (Drain): 52.8K Ohms

[Vesko356]

Re: Asus GL503VD Not charging or powering on

Okay, I measured both mosfets. I set my multimeter to 200K for measuring resistance. This are the measurements i got.

Left Mosfet:

Pin 1-2-3 (Source): 52.8K Ohms
Pin 4 (Gate): 52.8K Ohms
Pin 5-6-7-8 (Drain): 0.6 Ohms

Right Mosfet:
Pin 1-2-3 (Source): 52.8K Ohms
Pin 4 (Gate): 52.8K Ohms
Pin 5-6-7-8 (Drain): 52.8K Ohms

Exactly as I told you, 0.6 Ohms is a dead short. Now you must find what is shorting your main power line.

[Jasonexe]

Re: Asus GL503VD Not charging or powering on

I checked the schematic of this laptop with boardview and i see that the drain from the left mosfet is connected to a other mosfet close to the battery charger IC. I removed the left mosfet but still had the short. After that i also decided to remove the one close to the battey charger IC but still the same problem, (i marked it with a red cross). You can see in the attachment that there are other components that are connected to it. I'm not sure which one i should check next.

[Vesko356]

Re: Asus GL503VD Not charging or powering on

I checked the schematic of this laptop with boardview and i see that the drain from the left mosfet is connected to a other mosfet close to the battery charger IC. I removed the left mosfet but still had the short. After that i also decided to remove the one close to the battey charger IC but still the same problem, (i marked it with a red cross). You can see in the attachment that there are other components that are connected to it. I'm not sure which one i should check next.

There is no point in removing components this way, this is your main power rail and the short could be anywhere. Look carefully around the entire board for a component that is darkened or visually different from normal, it is most likely a ceramic capacitor. If you find nothing, the only way out is to inject 1 volt/2 amps and see for a heating component with a thermal camera or if you don't have one just feel with your fingers what is heating up.

[Jasonexe]

Re: Asus GL503VD Not charging or powering on

There is no point in removing components this way, this is your main power rail and the short could be anywhere. Look carefully around the entire board for a component that is darkened or visually different from normal, it is most likely a ceramic capacitor. If you find nothing, the only way out is to inject 1 volt/2 amps and see for a heating component with a thermal camera or if you don't have one just feel with your fingers what is heating up.

I will take a look, if i want to inject voltage. From where can i do it ? I don't want to kill the motherboard.

[mon2]

Re: Asus GL503VD Not charging or powering on

If you truly have a 0.6 ohms resistance to ground, injecting with 1v (NOT higher!), then the defective part will heat up and pop or crack like a pimple. (Ok, I am grossed out by that as well).

Often caps that will split and you can smell it once they. Have seen tantalum caps do this as well as ceramic.

You will inject the voltage at the mosfet pin that reads this low resistance to ground.

Red DC power supply pin there, black to ground. Do not go higher than 1 volt - just in case this rail is directly reaching the CPU but if it is, then the CPU is likely already dead.

[Vesko356]

Re: Asus GL503VD Not charging or powering on

I will take a look, if i want to inject voltage. From where can i do it ? I don't want to kill the motherboard.

At any point of the power rail, but in order not to do something stupid, it's best to be let's say after the second mosfet, exactly where you measured 0.6 ohms.

[Jasonexe]

Re: Asus GL503VD Not charging or powering on

i tried injecting 1v but i didn't feel any components getting hot. When i try measure the voltage where the short is while injecting it drops to 0.080v

[mon2]

Re: Asus GL503VD Not charging or powering on

How much current was consumed?

Is the CPU with a heat sink?