Asus Rog GL502VM Rev 2.0 - Power button LED on as soon as plugged in but no video or fans

[zwect]

I have this Asus ROG laptop (the 1060 + 6700HQ variant) which lights up the power button's LED when i plug the charger in but does nothing else. Opening up there are no signs of any burnt or corroded components, i've checked the resistance of both CPU and GPU's cores on the caps underside them, the CPU's VCCCORE's caps read 1.2ohm and the GPU's NVVDD read about 0.5 to 0.6ohm. I then tried to check any voltages while the laptop is plugged in (without any of the removable parts) and the GPU's core voltage instantly goes to 0.8v when plugged then getting slowly warm, the PCH does so too (not so warm as the GPU) but the CPU doesn't, also without any voltage going into it.

I'm not sure where to check next since the resistances are this low (even though i've heard about Skylake and Pascal having low resistances but i don't think they should be this low, right?)

[zwect]

zwect. I know it's an old post but did you end up knowing what the issue was? I am having same symptoms with my ASUS ROG GL502VS

shorted cpu.
I desoldered the inductors and the resistance outside the CPU area got normal, CPU itself kept 1.2Ohm and when i injected voltage on the caps below, only a specific portion of the CPU would heat up.

[mcplslg123]

Resistance to GND on Vcore at 1.2 ohms is too low in my opinion .However, the same is fine for GPU.
However, its too early to conclude. You need to give more details of the rails that are coming up and the missing rails.

[zwect]

Resistance to GND on Vcore at 1.2 ohms is too low in my opinion .However, the same is fine for GPU.
However, its too early to conclude. You need to give more details of the rails that are coming up and the missing rails.

thanks for the direction, here, and also, tell me if im missing something

+5VS_PWR is present at PU8100, PU8101 and PU8102 on pin 4 (but they don't seem to be switching on?)
+12V reading 13.8V (measured on PR8806 and PQ8806's 4th pin)
+VCCST reading 1V (from PQ8806)
+1.0VSUS is present (read from PCE8302)
+1.2V is present (read from cpu's caps below it)
+VCCSA is present (read from cpu's caps below it)
+VCCIO reads 0.9V on cpu's caps
+3VS is present, read from R7858
+3VA is present, read from R5701
+2.5V is present, read from C1608
+5VSUS present, read from PC9242
+1V8_AON is present, read from R7871
CPU's +1.0V_VCCPLL and +1.0V_VCCST_CPU are present below it
+VDDQ_CLK reads 1.2V

[zwect]

Hello?

[mcplslg123]

Link the schematic if already posted on this forum.

[zwect]

Link the schematic if already posted on this forum.

there's this one but i can't download the files https://www.badcaps.net/forum/troubl...atic-boardview
i do have the boardview and the schematic but i don't know if i can share them

[mon2]

Raised the alert to restore the links. Check back tomorrow.

[zwect]

Link the schematic if already posted on this forum.

https://www.badcaps.net/forum/troubl...ew#post1709160

[jasko_jacker]

There could be many causes, however I would check the PCH (the fact that it doesn't heat makes me think that the card doesn't post) and I would check the voltages of the two lines on the battery connector and if the ITE receives power. If there are no obvious shorts and these voltages are present I would try reprogramming the bios. Obviously a professional repair has a different approach....

[zwect]

There could be many causes, however I would check the PCH (the fact that it doesn't heat makes me think that the card doesn't post) and I would check the voltages of the two lines on the battery connector and if the ITE receives power. If there are no obvious shorts and these voltages are present I would try reprogramming the bios. Obviously a professional repair has a different approach....

SMB0_DAT_BAT_CON has 3.3V so does SMB0_DAT_CLK_CON

PCH's to GND has 68 to 70 Ohms

the +3VA_EC pin shown on the arrow also has 3.3V

[zwect]

I also tried flashing the BIOS again but nothing changed although the symptom of powering on by itself did disappear when the BIOS chip was absent.

[zwect]

Any clues?

[Sephir0th]

Everything comes up except +VCC_CORE. Also the resistance to GND of the Core is low. These are at least two indications for a dead CPU as mcplslg123 already assumed. You may want to check whether something.is wrong with or around the VRM Controller, like SVID communication for example. Other than that that's a dead end at this point.

[jasko_jacker]

1.2 Ohms may be few but you also need to understand how accurate the reading is. I would try installing a rebuilt bios.Furthermore, to understand the situation well, all the signals should be checked following the power sequence list or use the jdebug port. I have found myself in situations where the CPU was damaged and the card was not powered,

[zwect]

1.2 Ohms may be few but you also need to understand how accurate the reading is. I would try installing a rebuilt bios.Furthermore, to understand the situation well, all the signals should be checked following the power sequence list or use the jdebug port. I have found myself in situations where the CPU was damaged and the card was not powered,

Could you recommend me a good / the right device for using the debug port?
Would this one work for that? (seems like it works on the RAM slot instead of using the dedicated port.

[jasko_jacker]

if you need it for Asus systems, there is a DDR2/3 card (which can also be connected to the DDR4 via cables) and now also DDR4 which uses the RAM port, see www.bvg-group.ru (I don't know if they still exist) while to use the jdebug port there are many devices that are fine but you have to solder the cables or create a connector. they are only useful if the bios works and hangs on a specific code they are not like a jtag system

[waakye]

zwect. I know it's an old post but did you end up knowing what the issue was? I am having same symptoms with my ASUS ROG GL502VS

[zwect]

zwect. I know it's an old post but did you end up knowing what the issue was? I am having same symptoms with my ASUS ROG GL502VS

shorted cpu.
I desoldered the inductors and the resistance outside the CPU area got normal, CPU itself kept 1.2Ohm and when i injected voltage on the caps below, only a specific portion of the CPU would heat up.

[waakye]

Thank you so much zwect for replying. I guess I am in the same boat as you. Thanks again. The CPU inductors on mine measures 2.1Ohms and the GPU inductors measures 0.4Ohms.

[piernov]

https://www.badcaps.net/forum/troubl...es#post1459061

Re: Beginner's guidelines

2.2. Don't suspect that something is shorted with no reason
Shorted components are not the only failure mode of a laptop. Additionally, some places will measure low resistance to ground under normal operation. In general, high power low voltage (<2V) power rails will measure less than a few hundred ohms to ground. CPU VCore will measure a few ohms only. GPU VCore with newer NVidia GPU can even measure less than 1 ohm. It's normal. If you suspect a short to ground, always report your exact resistance to ground measurements.