Please help me fix an FX-7808u

Last year I bought a used FX-7808u from a friend who was going to throw it out because he thought it was bricked. He even sent it to Gateway to have them fix it, but they sent it back saying it couldn't be fixed. I took a look at it and realized what an absolute mess it was on a software side. He had so many programs loading at start up that it was just a clogged mess. I reset the hard drive to the factory defaults, and cleaned it all up using the Windows Vista Tweak Guide from TweakGuides.com, and everything seemed to be working great.

I gave it to my brother and loaded it up with a bunch of games for his Christmas present in 2010. He got about 9 solid months of performance out of it, but then it started to freeze with sound skipping and a black screen and the only way to power down was to hold the power button for several seconds. Initially, these crashes only happened at the end of the day after playing a game for several hours. But as the weeks went by, this crash would happen sooner, and sooner, and sooner. Now it will crash after only a couple minutes of playing anything that uses polygonal graphics, however, it NEVER crashes if he is just browsing the web or using a word processor.

I thought it might be a heat issue, so I decided to take the machine apart completely and apply ICD7 to the processor, North Bridge, and graphics card. I had done that to my FX-7811 a few months ago and had a rather drastic drop in temps, so I thought it couldn't hurt.

Well, when I got inside my brother's laptop and removed the heat sink from the processor and the North Bridge, there was no TIM Pad on it at all!

ABSOLUTELY NOTHING!



There was some kind of TIM on the processor, but there was nothing on the North Bridge at all. As I got further into the laptop, I also noticed that all 5 of the screws at the top of the keyboard were completely missing as well. I talked to the friend I bought it from and he said he never opened it, so I guess I have Gateway tech support to thank for the 5 missing screws and the missing TIM pad...

I replaced everything with ICD7, but it doesn't help. It still crashes after just a couple minutes. Using CPUID, the temps never get very high except for the TZS0 temp which is stuck at 91C from the moment it is turned on while plugged in and it only changes when I'm running from a battery. Then it is a normal 46C. In fact, the temp jumps between 91C and 46C when I plug in and remove the power supply cord.

Obviously, I think the North Bridge is fried because it didn't have any TIM on it for the past year, but I have a couple questions:

1. If that is indeed the problem, why didn't it show up earlier? Why was my brother able to play anything and everything for hours on end for several months before there were any issues?

2. Wouldn't the laptop crash at other times if it was the North Bridge? Why only after loading up a game for a couple minutes? 3DMark also freezes the computer after a couple minutes.

3. Is there a way to replace the North Bridge, or do I need a whole new motherboard?

4. Is there a cheap place to get a replacement motherboard for my brother, if that is indeed what I need to do?

Thank you for all your help, and if you would like any more information that could be helpful in solving this issue, please ask and I will reply as soon as I'm able.

 

1. The NB may have been originally pretty healthy but overheating has caused issues.

2. Games still cause alot of data to transfer from the CPU throught the NB.

3. my guess here is a qulified person could with proper equipment but it would be hard and expensive.

4. The best bet is a P79xx board as they are quad capable.

If you could try undervolting the CPU that may help. My Q9200 goes to 1.0050 v core to run at 2.66 GHz. This keep the TSZx much cooler. Also is your fan running properly on the CPU?

 

I think I've narrowed down the issue. While running CPUID, if the computer is plugged in the temp for TZS0 is 91C, but the moment I unplug the computer and just start running off the battery, the temp for TZS0 drops suddenly down to 46C. When I plug it in again it jumps back up to 91C after just a second or two.

I was able to play Skyrim for several minutes on battery power, but after just a minute of plugging it in again it froze.

There is another issue with the power connector on this particular laptop, too. The battery doesn't charge when it is plugged in. Rather, I just take the battery out and snap it into my 7811 in order to charge it.

It isn't an issue with the power brick itself, as I can use either one and it has the same effect on the 7808u, and either one works just fine with my 7811. Thus, it must be something wrong with the power connector on the motherboard. Any idea how to go about fixing this? Or will I just need an entirely new motherboard?

 

"Someting wrong with power connector" can't cause CPU or GPU overheating... And there are so many unknowns in your equation, so I'd suggest buying a new MB.

 

The powere noard is actually a daughter board but not sure if this will fix your issue with battery charging.

When you have battery only the board goes into power saver also most likely lower cpu clocks and NB stress. Also too thosgh battey only sticks the 9800m video memory into 2d mode. AC the video memory switches between 2D and 3D memory speeds causing a known issue with our systems.

first step is under volt and see if you can keep the NB temp down...............

 

The switch between 3d and 2d mode caused a lot of errors for me in the past until I came up with this solution. You might want to give it a try, since I the 7808u uses the same GPU, make sure before flashing vbios http://forum.notebookreview.com/gat...solution-nvlddmkm-video-crash-p-7805u-14.html (9800m gts 1gb)

 

will a p-79 quad work with the p 7808?....what actually needs to be done to do this?

did you ever get your laptop up and running?...i have the same one and im currious what you did to it.

 

A q9000 that is in the P7808 will work with the P79xx main board..................