my main board in my sons xbox 360 keeps giving error messages i.e e74 and 3/4 redlights . i've heard its a dry joint fault on main board and when i strip fans out and let it over heat then cool down it works fine for a few days then errors come back and i have to do it again. I'm worried about cooking cpu so i was wondering if i apllied fresh flux on joints and heated with a heat gun would this be a more perminent fix because the joints are so close to each other if i try to resolder i' might bridge the joints blowing the cpu

primey1, October 2010

No - you will destroy any functionality that already exists - very quickly and very easily.

A fine tipped soldering iron and very fine flux-cored solder is your only realistic approach.

Use a watchmakers glass to find dry joints - if there are any - often revealed by a faint "ring" around the component leg.

The common mistake of novice solders it too much solder and not enough heat - warm the joint until the existing solder melts - dab on the solder and after about one second - quickly remove the tip of the iron.

Do not be tempted to re-solder everything in sight - you are more likely to create dry joints. Only tidy up the known bad and very suspect joints.

Use Google - select Images - enter dry joint and see what a dry joint looks like. The bigger the solder "pad" the more likely there may be a bad joint - insufficient heat applied during manufacture.

Heat related faults can sometimes be diagnosed with a hair dryer and or a can of freezer spray - dry joints can sometimes be detected by tapping with the end of a wooden spoon.

Removing the cooling fan could be fatal for a CPU and I counsel against it.

Good luck...

Peccavi, October 2010