Asus N550JK-DB74T Powers up, fans, DVD Drive spins, single HD Indicator, Asus splash screen logo then hangs on a black screen.

[StewartA89]

So I have scoured the forum intensley for a solution here is the problem:

I have an Asus N550JK-DB74T which when I try to boot get's passed the Asus splash logo then hangs.

The responsiveness of keys which indicate if they are switched on or off tells me the system hangs (When I press the Cap locks key; If press it quick enough it responds to that light on and off, then nothing, it either sticks on or off)
The hard drive has been tested by myself and seems to have no issues, like I said the disc drive spins but to no avail.

here is the list of things I have attempted so far:

- I have reseated the RAM one by one, also checking operation in another computer (OK)

- Next was trying to boot with a LinuxLive USB/DVD/CD (FAILED)

- I then proceeded to break the laptop down into bare bones connecting to external monitor and no battery installed. Asus splash logo appeared and same as before (FAILED)

- I then proceeded to remove the CMOS Battery leaving it out for a day (FAILED

- I took the computer completely apart, cleaned it reapplying thermal pads or any thermal paste in specific areas where they were previously.

- I tried looking for any physical or visual damage on the motherboard, corroded areas or broken parts. But nothing looked wrong (FAILED)

- Attempted to use a PCMIA/USB Diagnostic card for post codes, vaguely understood parts of what was being outputted but I am uncertain whether this piece of hardware is useful or rubbish (FAILED)

- All key combinations known to man kind but laptop keeps hanging after splash logo (FAILED)

So I am pretty much at the end of any ideas bar one which would be my final resort.
It is worth mentioning this is a laptop which ironically operated on my desk as more of a desktop than a laptop so no physical damage in terms of knocking could happen. I would 9/10 put my laptop into hibernation mode and the laptop itself would be plugged all the time. It's running Windows 10 64Bit.
Again I don't use this for anything intensive other than heavy web browsing video streaming simultaneously etc. To add also I had it hooked up to two identical monitors one via HDMI and another via the Display port.

Here is the important part; I really don't want to RMA it purely for the intensive purpose of LEARNING how to fix things myself. I have struggled to find any schematics on this particular model so if anyone has them that would be greatly appreciated.
Also if anyone has any specific ideas on how to test parts on the motherboard for the process of diagnosing failed chips etc would be even better.

Please only serious responses.

Thanks

*Something else just popped into my head, but I vaguely remember when I tried installing new RAM modules on my friends lenovo laptop that it was locked down to specific hardware approved by lenovo. Could this be the cause? I fail to see how purely for the fact there is no POST message but then again it wouldn't surprise me if a vendor didn't add this. Lets say if for some unknown reason a driver for specific hardware in the laptop became corrupted? But surely it would go off the PID's of the device...I'm stuck

 

[W Fallon]

Asus N550JK-DB74T came with 8.1. Revert to it, then reinstall 10. Can be done through Safe Mode.

Or, if you want to play with it, get it to start in safe mode with networking (Shift key and restart). click Troubleshoot, should be clear from there.

You have an Nvidia graphics card and they do not play well with Win 10. Download the latest driver from ASUS, if that doesn't work, get the latest from Nvidia.

If still stuck use the 8.1 driver.

You're are going to have to sift through the drivers until you find one that works. Once you do, clean install it.

Bill

 

[StewartA89]

Asus N550JK-DB74T came with 8.1. Revert to it, then reinstall 10. Can be done through Safe Mode.

Or, if you want to play with it, get it to start in safe mode with networking (Shift key and restart). click Troubleshoot, should be clear from there.

You have an Nvidia graphics card and they do not play well with Win 10. Download the latest driver from ASUS, if that doesn't work, get the latest from Nvidia.

If still stuck use the 8.1 driver.

You're are going to have to sift through the drivers until you find one that works. Once you do, clean install it.

Bill

Sorry I think you have misunderstood or I haven't explained properly. It gets passed the Asus splash logo then the screen goes blank (backlight still on but its as if it crashes) I can't access safe mode, bios or anything

 

[StewartA89]

Asus N550JK-DB74T came with 8.1. Revert to it, then reinstall 10. Can be done through Safe Mode.

Or, if you want to play with it, get it to start in safe mode with networking (Shift key and restart). click Troubleshoot, should be clear from there.

You have an Nvidia graphics card and they do not play well with Win 10. Download the latest driver from ASUS, if that doesn't work, get the latest from Nvidia.

If still stuck use the 8.1 driver.

You're are going to have to sift through the drivers until you find one that works. Once you do, clean install it.

Bill

Another thing to add as well, the setup of the laptop served predominantly more as a desktop than an actual laptop. I rarely moved it as I have it hooked up to two other monitors.
Possible things which I think could have affected it are:
- I bough a cheap ish laptop cooler that sits underneath, has 3 fans and two back feet to aid in air flow. What I have been thinking with this is that, due to rarely moving it, could it have been possible that it built up a static charge from the fans going round (It sits on one of those heavy duty plastic work benches) and potentially caused static build up blowing a chip?

- I rarely shut the laptop down, instead I would put it into hibernation mode (I fail to see this as having any direct conflict in the boot up process)

- I have scanned the hard drive on my linux machine for any bad malware or viruses but nothing showed up. I also looked for the Windows logs just before it stopped working, again nothing of such notable use to help me.

- I have inspected the Mainboard too intensively (Although not knowing what to look for specifically is a bit of an issue) and can't see any scorch marks, degraded traces on the PCB or anything which would look to be an issue.

- If I may if anyone knows or has a copy of this machines schematics it would be very useful, I have looked absolutely everywhere; All I can seem to find is two pictures of the board view which again are useless really, and a few other bits.

- I ultimately want to try and test this board on a chip level (Yes I know I may need specialist equipment but I really would like to learn overall)

 

[Buck041]

I'm assuming the ASUS logo is hard-coded during boot (pure guesswork on my part), but if you hit F2 (BIOS) or F9 (recovery) and get nothing .. then it's very possible your BIOS is corrupt, and you are going to get your wish about learning down to the chip level. In the old days, you could buy a new EEPROM chip for roughly $10 USD ..pull out the old and install the new. I don't know if that is still possible today or not. If you aren't hearing any system beep codes, it's hard to say that your memory is the issue.

What I would do 1st, would be to "pretend" the PC is booting up, and go through the 'log in' prompts, then the 'microsoft' keys to shut down the PC. You'll need to practice this on another PC with the same OS, and write down the process, including your password entry. For example, on my Windows 10 machine, I would give my computer enough time to boot up to the Windows welcome screen... then hit ENTER, put in my login password, hit Enter again. After that, give it a few seconds to finish logging me in, then hit the Microsoft key.. then arrow UP 2 times, hit Enter, arrow UP 2 times, and hit Enter. If the laptop shuts down.. then you know the system is ok.

Keep in mind, I have no idea if your computer would be booting up directly, or going to the 'your computer did not start correctly' screen from your previous errors... I'm just trying to give another option.

GL

 

[StewartA89]

I'm assuming the ASUS logo is hard-coded during boot (pure guesswork on my part), but if you hit F2 (BIOS) or F9 (recovery) and get nothing .. then it's very possible your BIOS is corrupt, and you are going to get your wish about learning down to the chip level. In the old days, you could buy a new EEPROM chip for roughly $10 USD ..pull out the old and install the new. I don't know if that is still possible today or not. If you aren't hearing any system beep codes, it's hard to say that your memory is the issue.

What I would do 1st, would be to "pretend" the PC is booting up, and go through the 'log in' prompts, then the 'microsoft' keys to shut down the PC. You'll need to practice this on another PC with the same OS, and write down the process, including your password entry. For example, on my Windows 10 machine, I would give my computer enough time to boot up to the Windows welcome screen... then hit ENTER, put in my login password, hit Enter again. After that, give it a few seconds to finish logging me in, then hit the Microsoft key.. then arrow UP 2 times, hit Enter, arrow UP 2 times, and hit Enter. If the laptop shuts down.. then you know the system is ok.

Keep in mind, I have no idea if your computer would be booting up directly, or going to the 'your computer did not start correctly' screen from your previous errors... I'm just trying to give another option.

GL

I have tried that that was one of my first thoughts, but as there is no display on an external monitor, and after around 2/3 seconds the caps lock indicator either sticks to "on" position or "off" depending on what the system last receieved before it crashes.
I am writing this reply from my linux machine with the ram that was in the Asus machine and thats perfectly fine. I do think it is somewhere at chip level, but the issue there is knowing specifically what to do without messing up the whole board. I contacted a website that had a whole boat load of shematics, due to them not having my model and they said they couldn't get it, which makes this a little more of a problem.

Specifically the machine doesn't respond to any fn sequence apart from the fact like I said with the Caps lock keys.
It would be better if I could even boot from one of 3 devices I have tried, SSD (System one), Live USB (Tried all ports, CD/DVD Drive (Spins up for 5 seconds then stops), And a floppy disk drive.

 

[Buck041]

All things considered, it's most likely a CPU thermal meltdown.

 

[StewartA89]

All things considered, it's most likely a CPU thermal meltdown.

The CPU is still giving off heat on the heatsink along with the GPU, and integrated GPU. Would that still occur if it was the problem?

 

[Buck041]

You are still putting electricity to the MB.. the CPU and GPU are still connected. I'm not an computer engineer, I'm just basing my answer on the "possibility" that your CPU is toast, it's just still in the toaster.

 

[StewartA89]

I know that I wasn't criticising merely just trying to trouble shoot specific components that may be at fault.

 

[StewartA89]

I mean I have even gone as far as using a UV-Blacklight to see if there are any specific things that stand out, corrosion, moisture etc which could be short circuiting, but nothing. The only other thing on my mind is a corrupt bios of sorts. As to how to specifically flash the Winbond chip I am uncertain of.

 

[Buck041]

I know that I wasn't criticising merely just trying to trouble shoot specific components that may be at fault.

I never took it that way. I'm just being as practical as I can.

 

[StewartA89]

I know that I wasn't criticising merely just trying to trouble shoot specific components that may be at fault.

I never took it that way. I'm just being as practical as I can.

Fair enough. This one is stumping me really, I've tested a few resistors on the board and checked for any other broken traces but still nothing. I don't understand what has happened, if there was no power whatsoever then that would be understandable. The diagnostic card I have that connects a 25 pin parallel port to usb then outputs codes looks like its going through everything then nothing. It's worth mentioning as well I tried mounting the OS SSD in linux but i can only get it as read only, I'm wondering if the hibernate file is causing issue or is corrupt. It might be worthwhile seeing if I can wipe the SSD as trying a different hard drive maybe an issue also.

 

[Buck041]

The fact that you get nothing from the bios during boot, suggests (to me) that the issue is motherboard or cpu based. Based on all your info on previous posts, that's about the only conclusion I can draw.

 

[StewartA89]

I think I may need to look at how to reflash the bios physically, I've been looking into this prior to your messages and found one of two ways. The first I think requires a piece of hardware specifically a cable which latches on to the bios chip (not sure this is viable) the other is desoldering the chip and replacing it. Does anyone know of how to force flash when you can't boot or get access to the bios? I keep seeing so many conflicting ways to do it like download bios to CD, floppy disk, rename it to a ROM file etc