Just because your monitor can show non-red colors does not mean it is not suspect.
Your computer crashing every 5 minutes makes your monitor not suspect.
This is a way off guess considering you didnt post your system specs, but it wouldn't be surprising if you have a heat problem. And taking a fan off of something which comes with a fan, in my experience, voids the warantee. Run the computer with the case open and see:
Do the problems continue (crashing i mean, the red may be actual damage to the video card, which processes the info the computer gives it to provide a display). with the case open (letting heat vent if it is a heat problem).
Are any other fans in your system no longer spinning?
On the vid card, or any motherboard components, are thier darker spots which may show evidence of burn/heat?
Right after a crash, go into BIOS, and check your temps if you do not have a desktop temperature monitoring program. (The temps should show next on the same page where you set the shutdown temp limits)
Is the board, chip, or any motherboard components or fans covered in dust?
Checking the big dangerous stuff is good to get it out of the way. If opening the case while running does not help, and there are no signs of burning anywhere physically or in the BIOS, then you may not have a heat problem, which is progress towards a solution. The quickest heat test will be opening the case and not seeing your symptoms anymore (except for the red, which would possibly be perm damage).
Keep in mind, a steak doesn't cook through in a minute, and overcooking it may not burn it, but it would be dry and unappealing. It is possible that you fried something... But the symptoms seem like seperate faults... So you may have more than one problem, and heat (especially with a cooling problem like a fan stopping) would affect memory, hard drives, pci cards, and other electronic eq.