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Old 04-27-2004, 08:10 PM   #25
tw
Read? I only know how to write.
 
Join Date: Jan 2001
Posts: 11,933
Quote:
Originally posted by Undertoad
My Asus mainboard came with a utility that records the fan speeds and temperatures and voltages as measured by the mainboard. I have never seen these voltages waver one bit even under the maximum load I could manage to put on the system.
Only after calibrating that voltage monitor with a 3.5 digit mulitmeter will that motherboard monitor report anything useful. They are selling motherboards on the cheap. 5% resistors are far less expensive than 0.5% and 1 %. Did you notice that little descrepancy in the specs? Or did they just 'forget' to mention that critical information?

Now let's return to fundamentals of quality. There are good components, bad components, and unknown components. Three categories. Unknown components and good components both measure good voltages. Then a sudden failure with massive damage happens. Power supply failure also takes out disk drive, Ram, motherboard, CD Rom, etc. Where was a voltage measurement going to predict the crappy power supply from the unknown category?

Stable voltages only suggest a good supply. Bad voltages say, beyond a doubt, it was a crappy supply. No voltage measurement is going to detect a missing functions in that defective Sparkle supply.

3.5 digit multimeter can identify a failure. It cannot detect all design defects. Many conditions are necesary to define a minimally acceptable power supply. That Sparkle supply is the classic example of defective - even though it always measures good voltage.

Bad voltage measurements will explain why VSP's computer is failing. But a quality supply - the first of three possibilities - demands that the supply meet a long list of critieria. A stable voltage tells us nothing about a good supply. It only says the supply is not bad - today. That Sparkle quickly violates criteria for acceptable - even though its voltage measure OK today.

At this point I am appaulled I should even have to explain simple, fundamental technical concepts. PSU measures good voltage? Therefore it will never damage any computer? Where does this religion come from?

Once VSP has a meter, only then will we start a 'step by step' process to fix his machine. In the meantime, it would be nice to have specifications for his power supply - to avoid other future problems. Today, we need a few minutes of voltage measurements to only begin an analysis. Start by eliminating PSU as reason for failure - before even speculating on anything else.
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