Solved! Asus ROG 750J, Partially defect after a fall. Looking for help with troubleshooting

Jan 7, 2020
5
2
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Hello Users and Experts.
I apologise for my long post, in advance.
I will try to keep it as sharp and on point as possible.

I am in the unlucky situation where my laptop took a fall from a chair, to a concrete floor. Luckily 'protected' by a premium bag..

After the incident I plugged the laptop to AC through the charger, (as i have removed the battery a long time ago) and turned it on to see if anything took any damage.
I honestly didnt think anything had happend to it, as it was in its bag, which is of good quality, and the distance it fell wasnt noteworthy, (30-40cm) but i was wrong.

The laptop does not power on the monitor, but also not the logo on the back of the monitor. The rightside fan does not spin on startup as usual, while the left one does. The Keyboard, and status lights, light as normal.

I've tried taking it apart so much that everything is still connected, and see if a piece of plastic or something else was blocking the fan, and check for loose connectors to the screen, but i found none of those issues.

While the laptop was still in a state of whole, but taken apart, I plugged in a HDMI connected to my TV.
The tv registered there was power on the HDMI, and thus selected that, but it did never recieve a signal.
Here i gave up on it, and reassembled it, and put it on the shelf for a few weeks,
until today where i got the guts again to properly take it apart and look at it.
I've dissassembled it, so i can have a good look on all circuit boards;

I can see i have a small 'Surface mounted inductor of 150microhenry' where the shell is cracked, but asking a friend who knows about components (he told me what component it is) says that, that component is not the issue, though i should get it replaced.
He mentions something about a fuse, or fuse circuit, that might have taken damage, but even he is not sure..

Im now beginning to fear that the issue is something i cannot fix myself.
But before I give up the piece of technology whos been my best buddy everyday for almost 6 years, I turn my hopes to you..

I humbly ask for pieces of advice, troubleshooting methods, and even the occasional cheer,
as this beautiful old lady of mine, deserves an honest attempt of resurrection

Heres a picture of the broken component, just for good measure: View: https://imgur.com/0jUjaev


I hope you have a good day, and thank you for reading this far.
Best regards from Denmark
- Jack (Digital_Beast)
 
Solution
Did you try reseating the RAM (unplug and replug it into the slot) and removing the HDDs and the DVD drive, unplug the display and then powering on?

check the correct seating of the GPU (remove it and reinstall it)
the right side fan is for the GPU, might be something odd with the GPU connection or the GPU PCB itself

Could be a connection of a ribbon cable not tighlty connected anymore or a crack somewhere else

replace the inductor if possible

reset the cmos by removing the cmos battery for about 5minutes

eventually you can get a cheap motherboard for this laptop
Did you try reseating the RAM (unplug and replug it into the slot) and removing the HDDs and the DVD drive, unplug the display and then powering on?

check the correct seating of the GPU (remove it and reinstall it)
the right side fan is for the GPU, might be something odd with the GPU connection or the GPU PCB itself

Could be a connection of a ribbon cable not tighlty connected anymore or a crack somewhere else

replace the inductor if possible

reset the cmos by removing the cmos battery for about 5minutes

eventually you can get a cheap motherboard for this laptop
 
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Solution
Jan 7, 2020
5
2
15
Hello Helpstar

No i did not try reseating the RAM, while it was still in one piece, and I did not unplug anything.
I merely checked for loose cables and objects obstructing the fan, and testing if it worked with an HDMI.

I took it completely apart yesterday, it is currently, evenly spread across my dinnertable.


That will at least upon reassembly get me across the following steps:

  • Reseating the RAM
  • Reseat the GPU
  • Reset the CMOS
  • Re-installing all cables to ensure they have perfect connection

I wonder if i will need to complete your initial suggestion, about removing HDD's and DVD drive, and keep the display unplugged, when i power it on again, when its been taken apart completely? I am asking, so that I dont end up putting it all together and then realize I have to take it apart again :)

You mention i can find cheap motherboard for this model, Do you happen to know if replacing the motherboard will affect anything? Also another question if you dont mind, the laptops CPU is overclocked, from the assemblyline, will a new motherboard also be overclocked?

Thank you for taking your time to read and answer my post, I appreciate it a lot!
Have a nice day!
- Jack (Digital-Beast)
 
resetting the CMOS could set the overclocking to its default values as well

by "cheap" I mean luck that someone sells it´s own working one because of other issues on craigslist or ebay

If the HDDs and DVD drive is unplugged already and it still doesn´t power on to at least the BIOS screen, it shouldn´t make any difference.
 
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Jan 7, 2020
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Alright :)

I will try to reassemble it to a state where I can power up the motherboard,
and see if the bios will work at least, and work from there.

If I learn anything new, I'll post it here.

Thank you very much for your time, and help.
 
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Jan 7, 2020
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Hello again :)

After reassembling the Laptop it actually started up, screen turned on and it started up just as it used to :) (YAY!).
I did not change the cooling paste, when i assembled it, so i will have to take it apart again to replace it, and the cracked inductor, or maybe take it to a professional, since I dont have any sort of ESD protection equipment, other than touching my heaters, before operating on it.

The Startup being a success is limited a bit, because...
In the few minutes I had it turned on, I could not see the CPU usage in task manager and temperature with speedfan as I have been able to before the accident, and I did not feel the righthand fan blow, which is connected to the GPU. The GPU was registered perfectly fine in the Devicemanager, so theres still a bit of issues left with that.

My question now is, would the missing CPU temp and usage be something i did wrong when i reassembled it?
(i never dismounted the CPU Cooling pad from the Motherboard), but i reset the CMOS by pulling out the small battery for about 10minutes.
And can I safely measure the output voltage to the fan, with a multimeter, with the PC on, since I dont have a spare fan to test with?

As always i wish you all a good day and thank you for reading :)
- Jack (Digital_Beast)
 
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Jan 7, 2020
5
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Update.

I challenged destiny, and booted the pc up once again, this time i stayed for a bit longer, allowing the pc to update what needed to be updated etc, after a few weeks on the shelf.

I noticed that the readouts of temperature on the CPU came online, and the readings on the usage came back aswell.
I also noticed that the fan began spinning, when i opened a program, that required a tiny bit more, so it should be working nicely, again..

Using CPU-Z I could read that the overclocking was not reset, from the 10minutes without the battery for the CMOS, which is good news indeed!

The only thing left thats currently not working, is the backlight of the keyboard, and im almost certain that is an error on my part when assembling it, as I was struggling to get the keyboard cable in just right, and it will most likely be fixed when I assemble it after repasting :D

Now the only thing thats left to do, is to take it apart again, and repaste it, and replace the component :)
Then im back in business! :D

Thanks to all of you who read this post, and thanks to @helpstar for pointing me in the right direction!
I wish everybody a day that is just as great as mine!

Wouldnt cheat you for a few pics of my process:
View: https://imgur.com/gallery/XQgOj3L


Cheers
- Jack (Digital_Beast)
 
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