We’ve had a Dell Precision M90 laptop kicking around here for a fair while now with faulty Quadro FX 2500M graphics output. When the machine is powered on, the laptop’s LCD remains blank although the backlight is obviously powering up. If an external screen is connected, a picture is displayed at the POST screen but it is overlaid / disrupted by strings of what look like dots, commas or exclamation marks.
Since the machine is out of warranty and what we clearly have is a faulty graphics card, the question is now – why?
On extensive searching of the web, it seems that this problem is common to many of Dell’s high-end laptops with discrete GPUs and to date there does not seem to be a solid fix from Dell other than to change the graphics card (which may again fail) and update the machine’s BIOS to alter the fan’s duty cycle in the hope of reducing the thermal load.
This post and selection of comments on popey.com gives a little insight with people who have had warranty exchanges on their Dell laptop graphics cards reporting repeat failures later on. One interesting comment mentions the possibility of the components expanding significantly due to the heat and coming into contact with one-another where they shouldn’t causing an electrical short. Having looking at images and diagrams of the graphics card installation which attaches to a socket in the face of the motherboard, I’d be inclined to agree that it is a possibility.
I will hopefully know more once I have dismantled the M90 and gone fishing inside.