Hi all,
The LA-120 Decwriter that I got off Craigslist a couple of weeks ago has a dead H7150
power supply. Transistors Q1 and Q2 are open and shorted, respectively, and fusible
resistor R4 is open. I'd guess that failure of Q2 led to the other two parts going.
Q1 and Q2 are high voltage NPN power transistors in TO-3 cans, labeled
__
81 [ti logo] 41 (or maybe 4I but I'm guessing for a date code, 41)
R3004
BRITAIN
DEC part number appears to be 15-12782-00. The printset identifies them as "NPN 100W
S1325 15". I can't find any substitution info online. There is a NOS pair for
sale on eBay. So that's one option. Does anyone know what the modern equivalent(s)
are? And what if you do, where did you find the reference?
Thanks,
Brian