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Asus Rog G751JT Adapter Problems

Level 7
Hi all, I made a thread about this in the past but the problem has precipitously worsened since then. In the fall of 2018 my Rog G751JT would disconnect from AC power while gaming. My event viewer would be littered with 'power source' change notifications and gaming on AC was impossible because eventually the laptop would stop recognizing the adapter no matter what I did.

The "good" part about this issue was that it was only limited to high intensity gaming. I still had a usable laptop for low end/low intensity games, watching streams, Netflix, etc. While this was still an annoying problem given I bought this laptop for higher end gaming, I didn't do much to troubleshoot the problem and just used it as a 'regular' laptop to at least feel like I got some of my moneys worth out of it. It was already out of warranty and I couldn't find anywhere to send it or get a price for what it would take to cost to fix - and honestly reading the horror stories of it being sent to ASUS and STILL not fixed had me wondering if it was worth bothering with at I didn't.

However this past week the laptop started dropping its connection to the adapter under idle/light loads. Now as of last night, it won't recognize the charger at all...even off.

There are 3 likely culprits at play here, according to my research this is a notorious issue with these laptops:

The DC jack itself is broken.
The adapter is bad.
The battery is bad.

I do not think the battery would be bad - it is only at 3 percent wear level according to HWMonitor, though I do not know what that exactly entails. But the laptop has always been plugged in since I bought it in 2016. It was used for gaming with mobility being an afterthought, so the battery should theoretically be in impeccable health. Could it still have gone bad despite never being used or taxed?

The adapter could be the issue, but many posts I have read said that the adapter being replaced did nothing to rectify the issue. To compound to that problem, the OEM adapter for this model are not cheap. There are cheaper 3rd party models on Ebay, but I have not tested any new adapter out.

The DC replacement actually seems like by far the cheapest fix despite being one of the more technically challenging problems (anyone can replace an adapter but cracking open a laptop is always an adventure).

What is my recourse here? When the laptop is properly getting powered, it is still as fast as it was day 1. It still runs games at high FPS, and none of its components seem to be even remotely damaged or compromised in any way. Literally the only problem is the AC power...but obviously that is a big enough problem to render the computer completely useless.

Is it worth looking into fixing this? I love this laptop. Would it be worth sending it into Asus? What would the likely cost to fix it be? Are there any other possible culprits? I have found DOZENS of threads pertaining to this issue.

I will say I am likely going to be buying a Strix Scar series laptop soon, so cracking this laptop open and fixing it as a side project could be fun since it will no longer be my only laptop. I'd love to salvage this laptop because it is an amazing machine when working and still has relevant components three years after purchase. I just didn't want to sink money into it if it is a lost cause. Sadly it has no resale value (the working units still fetch a pretty decent price on Ebay) due to its issues and I'd never knowingly sell an item that has issues.

I would love to fix it though, and am willing to spend money to do so. Any advice would be greatly appreciated.

Received the part, but it's the wrong type for my rig: G751JT.

Since I had it apart, I decided to re-paste the CPU and video. Here are the pics:

I removed all the old junk and applied new thermal paste using MX-4, and I noticed my temperatures are higher than before. I also noticed that the compound that is not on the cpu/video looked like a different type as it was soft and not hard. I used MX-4 on all the same places after I cleaned the areas. Not sure if MX-4 is the right stuff to use, but I've used it on my desktop with excellent results.

Level 7
I finally got around to trying to fix this laptop. I ended up using Thank you to JD for pointing it out many years ago. I had actually known about it prior due to his Youtube videos repairing my same model.

I sent it to PJR on Thursday, 7/8/22. He received it today and replaced the power jack. Seems to be holding a charge now with the adapter I had sent alongside with him.

I highly recommend Power Jack Repair for your power port repair needs. The business owner is a stand up guy who sacrificed his personal time on his weekend to wait for my package to arrive, sign for it, and ended up working on my machine immediately.

He did not see any visible damage on the jack but I do not find it to be coincidental that as soon as he replaces that part the laptop suddenly can be plugged into again/hold a charge. On the old jack I could not get a light / charge no matter what I did. It was dead. Tried it at 3 different houses/outlets with the same result.

I will add something important to anyone revisiting this thread though - I never did end up testing a new adapter. I am not sure if I am fully out of the woods yet. I still have the original PCB so if it's a PCB problem and not a jack problem then I will probably get the same issues - same if its a motherboard or battery issue - but hopefully it was just a jack problem. Or hopefully it is an adapter problem if not a jack because in 2022 those are much less costly to replace than they were a few years ago.

But the PCB/Jack is almost always the culprit with this model I am finding. As I stated originally, the battery had almost no wear on it. The voltages from the adapter were all copacetic. But it went from losing power while gaming to losing power completely. I am confident it was the jack that was broken, I'm just hoping it wasn't also the PCB - as again we only replaced the jack itself.

The correct PCB part does seem like a pain to find in 2022. But I'm sure with some detective work it can be found.

If anyone has any questions, don't hesitate to ask.

When I receive the laptop back in a few days, I will run some tests and report my findings. I am just thrilled that it can at least hold a charge again. I have since upgraded so it working at full capacity is not a neccessity, but it would still be nice to get a few years yet out of this laptop.

Level 7
This is really strange. I could not get it to charge the battery after several attempts of plugging and un-plugging the charging brick. There was no orange light indicating charging. That was yesterday. This morning, I plugged in the charger and the orange light is lit indicating charging. WTF? So I'm not sure what the problem could be, but I did order a new jack from NewEgg as a last ditch effort. Not sure what would be causing this intermittent charging issue.