According to the data I have (from my DEC PSE days) - 15-12782-00 was a BUY69A http://www.digikey.com/product-search/en?x=11&y=17&lang=en&site… rds=BUY69A Phil -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Brian Knittel Sent: Sunday, June 16, 2013 7:19 PM To: cctalk at classiccmp.org Subject: Decwriter power supply transistors R3004 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