GPU 0 Die Temp Sensor ERROR on a MacBook Pro. Can anybody help?

Question

Hello.
My wife has a 15-inch, 2.4GHz MacBook Pro model 3.1 laptop.
All of sudden the screen started to flicker, and after that,  it could no longer be booted. Applelogo visible but the timewheel stops and nothing happens.
I managed to get hold of a copy of ASD (Apple Service Diagnostic) for her computer, and I found out what was wrong:
There is a test called "Temp Sensor - GPU 0 Die Temp" that fails. I get the following message:
"Temp sensor GPU 0 Die Temp test 1 - Sensor Reads Within Operating Range
- Check to ensure that sensor reads within operating range.
ERROR - Unable to read sensor
- TEST FAILED -
Temp sensor GPU 0 Die Temp test 8 - Sensor Noise Test
- Checks that sensor Noise is within spec.
ERROR - Unable to read sensor
- TEST FAILED -"
If I look in the "Hardware Profile" under "sensor" I find the following:
"Sensor
type:            Temperature
location:            TG0D
low-limit:            15
high-limit:        85
reading:            1.0
description:        GPU 0 Heatsink Temp
noise-tolerance:    1.0"
The thing is that the problem seems to be intermittent. It comes and goes. All of a sudden the test passes and I can boot the computer. Some days the computer can  work for a whole day, so it doesn´t  seem to be related to temperature.
What do you guys and girls think? Is this fixable by myself? Does anybody know where this sensor is located? Maybe it´s just a bad connection, since it´s intermittent?
I feel I have come a little bit on the way to be able to solve this issue, and it would feel like a failure to be forced to leave the computer at an Apple Service Center, if it´s even worth it to do that. There is a risk that the computer is not worth a repair.
Could someone please chime in here for a clever advice?
Thanks.
Bo Reimer.

Answer 1

Welcome Bo!
It may be related to a known problem with MBPs 3,1 and 4,1. Some had a bad Nvidea Geforce 8600M GT video chipset that could fail under high heat cpnditions. There is an Apple Repair Extension Program (REP) that will fix the defect at no charge for up to four years from date of purchase:
http://support.apple.com/kb/TS2377
You'll need to have an Apple retail store or an authorized service provider check the computer with a special test gadget for positive ID of the problem to qualify. If it does, you get a new logic board. Reported turnaround for the fix is from same day to three days.
If their test does not turn up the Nvideo curse, you still have an affordable repair option if you live in North America (It would he helpful if you fill in the "Geographic Information" field in your profile--at this point I'm having to assume you're in N. America)).
The option is a depot repair. Apple sends your computer to their central refurbishment facility and bascially fixes anything outside of cosmetic damage for a flat fee of about US$315--much cheaper that a new computer. Taxes and shipping may apply.
People who have used this option are reporting excellent results and a turnaround of about one business week.