Compaq Presario F700 cycles on & off

computernerd62 · 06-22-2011, 02:54 AM

I have this Compaq laptop notebook that was given to me & had it apart all the way down to the mobo to check the Nvidia GPU & AMD 64 CPU cause the Fan & cooling fins were full of dust bunnies big time. Could not find any problems with the two chips except the GPU had no paste on it just a small brown sponge pad & the CPU did. It was cycling on & off once I powered it up. If I press the ESC or F10 buttons it would stay running but still no screen. The fan & lights would all function normaly. The HDD turned out to be bad mechanically & replaced it with a new 120 gb 1500 rpm. Has no bios screen come up either cause it won't stay on long enough to see one even when I press the ESC or F10 buttons.
All lights were illuminated & stayed on. DVD drive & HDD spins up normally. Has no screen illuminated. WIFI illuminates amber. Now i'm at a standstill & might have to take it all apart again after I cleaned all the dust bunnies out since cleaning it didn't help a bit.
Thought I might try the YouTube video's procedures by heating the GPU on the top & bottom of the MOBO to see if it might help but kind of skeptical about doing it.
Thank's for any support!

GZ · 06-22-2011, 12:01 PM

Hello computernerd62 and welome to TSF,

The most likely cause for the issue is the GPU. The F700 was one of many laptops affected by GPU issues. Basically what was happening was, the GPU would heat up and cause the solder that connects it to the motherboard to soften. Over time, repeated heating and cooling cycles, along with electromigration cause bad solder joints between the motherboard and the GPU.

The heating of the GPU, as you stated, is a way to attempt to "re-flow" the solder and restore the connection. This method is usually combined with steps to increase cooling to try and prolong the "fix".

The proper way to fix this issue is to have a professional with the proper equipment, remove the GPU from the board, clean and prep both surfaces, replace the solder with a higher quality solder and then use IR to reattach the GPU to the board. A BGA rework is expensive, and IMHO not worth it.

A home "reflow", when successful can prolong the useful life of the computer by a few months, but the issue will eventually re-occur.

computernerd62 · 06-23-2011, 01:56 AM

Thanks gavinzach for that infomation!
I think i'll just find another board & be done with it.
Less expensive that way don't you think?
Since I already had it tore down completely to the board the first time & wasn't that bad for my first time in.
Cost less for a new board than rather send it out to have it reflowed I think.
Again thank's!

Dave

GZ · 06-23-2011, 02:01 AM

If you can find a board that is inexpensive enough. Be aware that a large percentage of used and "refurbished" boards out there are boards that have had the same issue you are having now. I, honestly, think that your best bet is to cut your losses and run. Sell the rest of the computer as a parts machine and use the money towards a new laptop.

Just my humble opinion.

Whichever you decide, the best of luck to you!!!

computernerd62 · 06-24-2011, 02:23 AM

Didn't have to cut any loses on this laptop. It was given to me for nothing.
I might just use it for practice on the home reflow as you put it fix to get it going for a short time & be done with it. Wanted to fix it for my Nephew. I have my own M465E Gateway laptop & I wouldn't part with it for nothing. Alot better than a HP by far.
Thank's for the advice!