P68xxFX to P78xx/P79xx Conversion for those who want to know...

Hello Everyone,

At the request of forumite Hydra, I have decided to detail my conversion story. I will highlight the differences between the major revisions and where potential stumbling blocks are for anyone wanting to do the same thing.

Background
I found a great deal on a P6831FX that was bone stock. DDR2, 8800m GTS, T5450 and 200gb drive. The only problem with it was that the GPU had the typical over heating/unsoldering issues that most P68xx users experience eventually. Everything works fine except video. Heck, you can even hear the darned thing get past the Windows 7 starting theme.

All the cooling help and cleaning will not stop the ultimate demise of these boards which is the 8800m GTS being a hot GPU, a poorly designed (insufficient) heat sink, and the RoHS switch to lead free solder.

My initial solution was the typical baking in the oven process. Set the board in there at 400 degrees F for 10 minutes, let it cool, reassemble and enjoy...for a while. This worked great and made my $120 investment in the P6831FX the steal of the century.

But, you will have to repeat the process for 3-4 more times over the course of 2 years before a full reball is needed. That price alone puts you at half the cost of a newer revision of this board from a P78xx or P79xx.

Eventually, I gave up with the P68xx board and decided to explore my options. The chipset was only good for 800mhz FSB and used DDR2.

P68xx conversion Mk I
Fellow forumite psyauto hooked me up with his old P7811fx board for a great price and work began to figure out exactly what was needed to get it to work natively with no issues.

First off, the P68xx boards have DDR2 and the PM965 chipset. The P78xx has the PM45 chipset and it is common among all the P78xx and P79xx boards. This allows the system bus to run at 1066 MHz as opposed to 800 MHz like the PM965 of the P68xx. This requires DDR3.

[*]To get to 1066 Mhz front side bus, you also need a CPU that is capable. But the board did run with my T5450 which was 667 MHz so this is not a requirement.
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The P68xx also have a separate lead on the media bar that runs to the board for the power switch as well as a switch on the media bar for "Windows Hot Start." The P78xx & P79xx do not. They use the same ribbon cable for the media connector, but the power switch connection on the board is not there. You can start it without the newer media bar sometimes with the hot start switch. But...it's not ideal. When I was waiting on my newer media bar, I just used a screwdriver to short it. I DO NOT ADVISE THIS THOUGH!

The P68xx series have a DVD drive interface that is not mini SATA or whatever its called. It's the older style. I presume the switch over in the industry happened in 2009 or so as the P7811FX board and the P7908u board use the mini SATA connection while the P68xx do not.

Except for those differences, the boards from any generation FX will fit perfectly. Same layout, same mounting spots, etc. Even the GPU heat sink will mount up without issue. No, it doesn't cover all the RAM modules like it did in the P68xx because the new GPU has a different RAM layout. But it works.

For any user jumping from P68xx to either P78xx or P79xx boards, here is what you will need at a minimum.

• DDR3 (10666 speed preferred) - No more than $20 if you are cheap like me
• P78xx or P79xx Media Bar with the media bar boards working and ribbon cables connecting them - found mine in Canada for $20 shipped, complete; lots of these are stripped apart, be careful!!!
• Newer style DVD drive with traditional SATA interface arranged for laptop use - was patient and found mine for $9.99 shipped on the evilBay

The P7811FX board worked great once these components were put together. The performance of the 9800m GTS was much better than the 8800m GTS in the older board. Could be the DDR3 system ram, or the GDDR3 ram, or some voodoo in the actual GPU. Not sure.

My main issue was that even with good thermal compound, my GPU was heating up to the low 90 degree Celsius region under gaming with low settings. It peaked at 100 degrees Celsius. That and the fan controller was whacky. Constantly modulated up and down and when gaming was very loud. No big deal, but my temps were unacceptable.

I tried undervolting the GPU but found out the P7811FX is a step child in the 9800m GTS series and the GPU BIOS can't be separated from the system BIOS. So no undervolting for the 7811FX. I know the other 78xx boards don't have this issue. Plus they have 1 GB of GDDR3 ram as opposed to 512 MB GDDR3 in the P68xx & P78xx. Better performance is to be expected.

My next step was to simply upgrade the GPU heat sink with one from a P79xx system since comparing the two side by side, you could easily tell it was superior. Use eBay to compare pictures of the two. I was hoping this would do the trick and get my temps down.

P68xx conversion Mk II
So I found a decent deal on the P79xx GPU heat sink locally and as it turns out, they were an Acer/Gateway parts dealer. They essentially bought systems that were brand new and parted them out. Typically, they had contracts with the Geek Squad for plastics and other parts but they also had a side business on eBay which is how I found them.

Walking into their warehouse was like a nerd's dream. CPUs, RAM, Hard Drives...strewn about like crazy. Just in the front office! The girl helping me knew all the model numbers I was throwing out by heart. Kind of sick really.

When waiting for the GPU heat sink, I asked her about having a P79xx series board available. Initial quote was $399. She knew that wasn't right so she called her boss and gave me the new price of $249 plus tax. Plus it was a brand new system pull. It took them 20 minutes to get it out of the system in the first place. (I could have pulled it in 15 min). Best part is that like the P78xx board, it shares the same PM45 chipset. No re-installation of Windows and everything should be very simple.

So on an impulse, I bought the P7908u board and walked out of the store with my newer style GPU heat sink. Swung by Fry's Electronics and picked up some Antec Formula 7. Got it home, installed everything and booted right up.

This happens to be one of those happy endings that aren't usually associated with impulse buys. My temps on the GPU never go above 65 degrees Celsius with medium settings on The Witcher. The performance of the 260m GTX is superior to both the 8800m GTS and the 9800m GTS as well as running a LOT cooler.

I also switched out my CPU for a P7350 which is a 2.0 GHz 45nm 3MB cache 1066 FSB chip. Just getting the bus speed consistent across the board really improved performance as well. My temps have reached 45 degrees Celsius once or twice. This is on the original P68xx CPU heat sink. I am not even sure there is a revised CPU cooler for this since I have had no need to look.

Words of caution: Be VERY careful with the ribbon cables. Do not be afraid of pulling the system apart. There is a great sticky at the top of the forum here for disassembling this laptop that can really help. But be VERY careful with the ribbon cables as stated before. Make sure there is no power connected to the laptop when pulling it apart. Those ribbon cables will burn up quick.

Also, be very careful with the LCD cable. I tore one up bad and had to get a new one.

I will post up some pics of the differences between the P68xx and the P7811fx boards at a later date.

EDIT: So here are the pics...I lied. The other board is a P79 (a busted up iPower board). The main physical difference is the CMOS battery connector, the mini SATA port for the DVD drive and the absence of the power button connector. The green board is the P6831FX and the blue is the P79xx.

 

OHH nice . Keep that gateway kicking some computer =). Also where is this located that you were explaining

 

The 260m is great compared to the 9800m. AS mentioned those ribbon cable are delicate........

 

Thanks for that! +1

 

Could you post pics of the new vs old heatsink? Thinking about upgrading a friend's fx laptop and she still only has a 9800m gts. Had to cut the rpm wire on the graphics heatsink to get good temps from it, wouldn't turn on until the card hit 70c, which in turn heated up the whole unit. So I just want to see if the heatsink would be a worthy upgrade

 

I am not totally sure if it is the cooler or the 260m gtx that makes the difference or not. But, I do like the idea of an integrated cooler. The metal is definitely attached to the heat sink and I think it helps dissipate heat better than the detached version.

 

Ah yes certainly more metal mass getting cooled with the newer revision. Since the fan housing is also metal the air movement from the fan would help it cool much better

 

$249 for MB+260m.

Marshallnoise, are the newer 7908 fan/heatpipes available from your source? What will these cost please.

Those fans are the same style as in my Tosh

 

I would expect, like anything, that the heatpipes would be available depending on what they bring in to part out. The company is called Adeal and I believe if you search either on eBay or the web, you would find the information. The cost for me was $27 bucks for a brand new one. Not bad.

 

hydra, i got the same one as marshallnoise. $25 + $9 shipping. part #60.4FE04.001 eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

 

Anyone have a place to get this mobo (new) at a reasonable price? Adeal is out of them

I currently have a p-172x FX with a defective gpu, the replacement board for this model is only 79.00. If i get this mobo and upgrade the gpu heatsink fan from the 7908 model will that fix the issue that current FX owners have with the gpu failing? Do we know if the problem for these models is the heat or the gpu chip or the thermal paste?

thanks in advance

 

The 260m does not seem to have the solder issue of the older nVidia GPU's. It is a costly fix though......

 

with the ability of the new GPU, and the fact you can go from Dual to Quad core processor's... $250 is rather cheap compared to buying a new system (desktop OR especially laptop)...

 

Don't bother with a quad core. They just are not as fast for most tasks as dual core. Clock for clock though with windows 8 the quads hold up for single threads but not in windows 7 and before.

Also the DVD and other components may need updating. The media bar on other than the P78 will definately need updating............