Dear mahmood Elnasser,
"vga signals isolation problem ( I think) ...."
Why 'I think'.There are standard procedures to pinpoint
a faulty stage,specially when ,as in your case,the problem is not intermittent.More on those standard
procedures later.
"My vga driver chips on the computer side keep exploding (60$ ea) very often."
This type of 'high level'description of the problem will never do.They say while trying to vividly describe a problem you often stand to have solved most of the problem itself.You,my dear mahmood Elnasser,are careless about details:
(1)schematic
(2)keep exploding - picture,sound,smell and if possible more.
(3)very often - exactly how often?
(a)is it repetetive?
(b)have you tried to connect an milliammeter in series with the power supply of the 'going to fail' chip?Results? You may spare a voltmeter right across the power supply pins of the 'going to fail' chip.
(c)does it fail after the period (a) even when nothing else is connected.Try to simulate the fault in varios conditions like no input,no output,no plus,no minus etc.Please try to start from the safest which you are sure should not fail and then keep on adding peripherals,strictly one by one,be sure that it is not failing even after prolonged period,keep record,and only then proceed to add more.
Are you game?
Incidentally how do one be sure that an earth is an earth?But on all those later.First let us isolate the culprit.
Trouble shooting,my dear,is more like assembly language and less like C.
Regards
A.S.Rudra