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
the failure of Q2 took out the other two parts.
Q1 and Q2 are high voltage NPN power transistors in TO-3 cans, labeled
__
81 [ti logo] 41 (or maybe 4I, no matter, it's a date code)
R3004
BRITAIN
The DEC part number is 15-12782-00. The printset identifies them as
"NPN 100W S1325 15". I can't find any substitutions online for either
R3004 or S1325. (Or 15-12782-00 for that matter).
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