Resistor/Fuse replacement (DEC H7104-D)
derschjo at gmail.com
Thu Mar 17 17:34:05 CDT 2016
Hi all --
Yesterday I replaced the dead 2N6547 transistor in the H7104 and fired
'er up again. Same exact results. (The timbre of the power supply
whine may have changed slightly, it's hard to tell). So, back to the
drawing board. I tested the replacement transistor after power-up and
it was still good, so at least it wasn't a casualty.
On closer inspection, I found what appears to be a large-ish (maybe
2.5-3mm in diameter) resistor with a hairline crack down the middle.
Testing reveals it to be open-circuit, and looking at the print set
reveals it to be connected to a leg of the transistor I just replaced,
so that seems suspect. I noted no smoke or odor during any of the times
I've powered this thing up (the resistor is on the outside edge of the
supply and I was watching pretty closely at all times) so I assume it
was dead long before I got ahold of this machine and I just overlooked it.
It's listed in the print set as a 1 Ohm, 2 Watt resistor, with a "FUSE"
designation. I'm not entirely sure what I should be searching for for a
replacement; clearly the "fuse" part of the designation is important but
I'm not sure what a modern equivalent is. I've browsed around Mouser
for awhile and I'm not seeing anything obvious. I'm sure this is
obvious to anyone with experience -- can you point me in the right
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