Ashdown MAG 300 amp, 2004
"Arfa Daily" wrote in message
...
"N_Cook" wrote in message
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Both 6.3amp fuses blown, 2 diodes of the bridge rectifier s/c. Internal
failure of this bridge, dodgey looking splodge logo, presumably Fronter
logo and 8amp rating, marked
AC BP8-04
or something else to change as well?
Main caps look ok and ESR (for what its worth in such cases) ok
The 2 failed diodes are
-ve to AC
+ve to other AC
Suspiciously 2 solder points look like crazed PbF solder but all is SnPb,
melted and reformed? the 2 points are at the -ve terminal and the AC
terminal of the other failed diode. Output devices DVM-D cold test as
expected. No heated traces or even obvious gaseous eruptions from the
bridge or anything out of the normal. No reported preceeding noises prior
to failure.
I've replaced a few bridges on various Trashdowns. Maybe just not very
good quality ones used by them ? Bad snubber caps across the bridge diodes
? Maybe none at all ? Power surge at a 'village hall' gig maybe ? Bear in
mind that there's been a lot of lightning around the last few days ...
I've just had a mixer come in dead. It apparently failed during a storm
when there was a power surge due to the cellar at the venue where they
were playing, flooding ... :-\
Arfa
I have had 3 Ashdown Electric Blue 180 amps with failed mains transformers
so far. (Shorted primary)
The replacement toroid Ashdown supply is a lot bigger.
Gareth.
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