Asus ROG laptop no power

[stevo1210]

Hi Everyone,

Just cleaning the house today and I found an Asus G550J ROG laptop. It was in a laptop bag behind a door collecting dust. Asked my brother about it and he said it’s been there for two years plus. His friend dropped it off to get it going again as it just died one day all of a sudden. My brother said he thinks the motherboard is dead because it has no lights on at all.

I decided to tinker with it. First thing I measured was the power supply, it shows zero volts. No output power at all! I’m guessing this is why the laptop isn’t showing any signs of life.

I advised my brother of this but he said he tried the power supply from his Asus ultrabook 2 years ago, and it didn’t boot at all either. Checked the PSU he tested it with and it’s a tiny 45w thing - although it is still 19V and same connector and polarity. I decided to try the PSU from one of my other laptops, a 65w unit this time at 19v 3.42A. Still no lights or anything.

The Asus ROG requires a 120W power supply. Thats 19V and a whopping 6.5A or so! My question is... is it possible the laptop isn’t showing any signs of life since the power Im feeding it is inadequate?

Thanks.

[caspian]

I have seen such a stay-off mechanism in desktop gaming mainboards, but not in laptops. at least, something will be displayed on the screen. try turning it on using a lab power supply. In addition, check whether the 19v rail on the laptop is shorted.

[zpi]

Best thing would be with lab power supply as mentioned before. Than you could see if it is even trying to start and how many A is using. If laptop is still with battery, try to leave it for charging for few hours, maybe battery will come to life.

[sparrow2719]

Originally Posted by caspian

I have seen such a stay-off mechanism in desktop gaming mainboards, but not in laptops. at least, something will be displayed on the screen. try turning it on using a lab power supply. In addition, check whether the 19v rail on the laptop is shorted.

Agreed, it will display anything if it is still a live, even under low ampere charger, at least the asus rog logo on boot.

Been try it before ...

[stevo1210]

I take that back. The Asus charger actually does have 19V coming out of it after I re-measured it - something is dead in the laptop, not the PSU as first thought.

[myth77]

its hard to tell this way without looking...
First, i think this charger doesnt have a light on it? to see if its on or off?
If so... maybe the laptop is shorting charger (thats why at the first you didnt find any voltage on charger). then later the charger turns off safety measures and bring voltage on. So, first, put the charger in the laptop, take it out and then quickly measure voltage on charger. If voltage is ok then charger is ok, and motherboard high voltage nets are ok...If so you have to look forward, find the schematic, boardview.... and start looking where is the problem....
If voltage is not ok, then your laptop is shorting motherboard, this could be a good thing, meaning that maybe some high level mosfet is dead, and it needs replacement, but its not always the case...

[SMDFlea]

check the CMOS battery voltage and the connector for corrosion .

[jasko_jacker]

I fixed a motherboard of the same type last week. These cards have a common problem concerning the PCH SR17E. There are no controls on the power of the power supply, however you must start by checking the two mosfets near the power supply jack, are they drived correctly by the charge manager ic?

[Francisamd1]

Help pls.. Bios for GL552VXK Rev. 2.0 tanx