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Old September 21st 04, 11:16 PM
Dave Platt
 
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In article ,
Me wrote:

Check to see if any or all of the pass transistors are shorted.


Bzzzt, wrong, would you like to try for what is behind Door #3?

If the Pass Transistors were shorted, you would see the voltage of the
filter capacitors and rectifiers on the output. He stated that he had
"No or little output voltage". This would indicate that the Pass
Transistors are OPEN, blown that way by the High Current when the output
was shorted, or the rectifiers are blown OPEN and not producing any
DC to the filter caps.


It's still darned good advice. If there's a fuse or fusible component
between the DC filter caps and the pass transistor, it might very well
have blown if the pass transistor shorted during an overload.

From what I've heard, bipolar power transistors are as likely to fail
shorted as they are to fail open.

--
Dave Platt AE6EO
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