[Ham-Computers] Re Ground Loop Potential

[Duane Fischer]

Hi All, 	
	
This Compaq business machine model 5100 continues to destroy the integrated
sound chip on the mother board. The last MB replacement lasted 17 days!
Thus far, none of the "technicians" dispatched here on site seemed to have
a clue about measuring the resistance between the sound output jack and the
external amplified system.  	
	
The external speakers are by Lab Tech, no woof woof, just one with the
amplifier and the other slave speaker. The main unit has on/off, volume,
bass, treble and headphone jack. I paid $80 for them about eight years ago
and they perform well enough.	
	
For some unknown reason the sound chip suddenly fails. Since I only use
this super computer for e-mail, with firewall and anti-virus software kept
current, it gets little use. I do not surf with it. There is much I could
do with it, "if" it were reliable!	
	
I use a dialup connection. I use MSIE and Outlook Express version 6.0 The
OS is Windows XP Home Edition.	
	
I have a UPC and two surge protectors before it! The system, including
monitor and speakers, run off the battery of the UPC. Thus I should not be
getting voltage spikes etc.	
	
Could this failure be caused by a ground loop existing between the sound
chip and the external powered speakers?	
	
Gentlemen, I am desperate! This is a fabulous system, but useless to me as
is. I am sick of repair people showing up, replacing the MB and saying "it
is cured!". Something is wrong somewhere and they are not finding the guy
with the gun shooting my sound chip! I need suggestions, I need solutions.
Ideas?	
	
Thank you.	
	
Duane Fischer, W8DBF	
dfischer at usol.com	
	
P.S. I am on emergency backup laptop for e-mail.