asus g74sx disassembly and cleaned no longer posting

[Danteu]

my girlfriend and I took apart her asus g74sx because it was idling at 80c. when we took it apart it became apparent to us that the thermal paste had been completely dried out.

We then reapplied thermal paste to the cpu and gpu and put it back together.
The fans are spinning and working but the screen is blank. We're wondering if maybe the CPU isn't seated correctly or what it could be.

We could really use some help trying to fix this. we've been at this for over 6 hours today. We're thinking about taking out the hdd's and cd drive to see if we get any error beeps.

 

[C12Friedman]

If you are fairly positive it was reassembled properly, I'll suggest attempting a reset - with battery removed and power adapter unplugged, press and hold the power button for ~30 second. Put battery back in, plug in adapter and try powering on

 

[Danteu]

If you are fairly positive it was reassembled properly, I'll suggest attempting a reset - with battery removed and power adapter unplugged, press and hold the power button for ~30 second. Put battery back in, plug in adapter and try powering on

We did that but only the fans came on. Do you think resetting the cmos might fix this? We really do appreciate any replies. we watched numerous videos on how to disassemble the notebook and followed them 100% its quite shocking to us that its not working. we were expecting to reduce the internal temperatures by 30c or more not have a notebook that doesn't work

 

[C12Friedman]

You can reset CMOS, it shouldn't hurt anything and it may work. If it doesn't, it may be that it needs to rest a few hours to allow any poly-fuses to reset themselves. I'll suggest checking the graphics connector inside since I found those to be tricky at times and more than once after I thought I had fully inserted one I found I didn't get it in properly. Another thing to try would be hooking up to an external monitor (or TV) and see if anything that way

 

[Danteu]

You can reset CMOS, it shouldn't hurt anything and it may work. If it doesn't, it may be that it needs to rest a few hours to allow any poly-fuses to reset themselves. I'll suggest checking the graphics connector inside since I found those to be tricky at times and more than once after I thought I had fully inserted one I found I didn't get it in properly. Another thing to try would be hooking up to an external monitor (or TV) and see if anything that way

Thanks for replying! we have no way to hook it up to an external monitor, no HDMI cord and the laptop doesn't have a VGA out sadly. we're going to take a break for now and try again later. Any chance you could find a picture of what the graphics connector looks like? We will reply with any changes.
Again Thank you for taking the time to reply to our problem!

 

[C12Friedman]

In this image it is listed as the LVDS cable

found here http/btoforums.com/showthread.php?p=18113

 

[Danteu]

So we cmos reset. the fans and hard drives are spinning but no display on the screen, we shined a light on the screen to see if the backlight was dead but still no image no error beeps. no clue why its not posting =( we're pretty desperate to get it up and running. does anyone have any idea why its not posting? everything is in its right place.

 

[C12Friedman]

Check that the CMOS battery is at 3V - on some PC's the CMOS battery being bad can cause strangeness.

 

[Danteu]

Check that the CMOS battery is at 3V - on some PC's the CMOS battery being bad can cause strangeness.

I imagine the battery isnt bad as it was working prior to us reapplying thermal compound.

*UPDATE* we plugged it into an external monitor but no video came up and we also tried FN+F5 and FN+f8

 

[Danteu]

Was told via btotech that you should never reapply thermal paste to a laptop can anyone verify if that's true?

 

[C12Friedman]

Was told via btotech that you should never reapply thermal paste to a laptop can anyone verify if that's true?

That's about the silliest thing I have heard in 30+ years of working inside PC's and sounds to be someone's personal opinion. Did they elaborate why or provide any reference?

 

[Danteu]

Was told via btotech that you should never reapply thermal paste to a laptop can anyone verify if that's true?

That's about the silliest thing I have heard in 30+ years of working inside PC's and sounds to be someone's personal opinion. Did they elaborate why or provide any reference?

Thats what me and my gf thought! and we asked another tech forum and they were such dunces...they thought the thermal compound pictures was us applying the thermal paste ~_~

I'll quote them "Someone on forums gave you advice to repaste. That is the worst advice one can give you. Its ine thing to clean the radiators its very bad to repaste this notebook and most other notebooks made after 2007. It doesnt help core temps and it opens the possibility that the notebook will never turn on again."

 

[Danteu]

we checked the cpu pins and none of them were bent, all the LED's light up when power is added(like when the battery is added or HD's). So very confused as to why its not posting. everything is as it should be =/

 

[C12Friedman]

Wow, I'm stumped at this point - I might suggest a few things that have worked for me in the past for like issues.
1) Steam clean the board with distilled water - there may be oils or dirt on the board causing issues. Electronics cleaner can also work but my preference is steam - need to wait 3-5 days for board to dry thoroughly afterwards if steam cleaned
2) Check the legs of all IC's for foreign matter which can cause IC's not not function properly (and sometimes gets very stubborn about leaving). I've found that a plastic toothpick is good for cleaning between IC legs - you'll likely need some magnification to look those over

That's all I've got at this point

 

[MrJak]

Out of curiosity, did you use a metal based thermal paste?
Because, while the chance of permanent damage from this kind is minimal to none, there's a small chance that it can cause some issues.
I, for one, applied some to a GPU with a bare die, as your laptop appears to be.
Almost immediately after, when testing the temperatures, it was crashing the PC, until I reapplied it, and made sure to keep it from overflowing any at all -- after that, it was fine.