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Old 09-11-2018, 10:02 PM
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bgadow bgadow is offline
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Join Date: Oct 2003
Location: Federalsburg, MD
Posts: 5,814
Funny that fuses would get mentioned-get a load of this:
I tested the fuses and they were all fine, which was encouraging. I did power the set up briefly only to find a light show inside the 5U4-whoops! While studying the schematic I was trying to figure out why no fuses blew. Well...somebody long, long ago (they were covered with a thick layer of dust) replaced 2 of the three with 2 amp fuses and the third with 1.5 amp! Yep, well, think of the cold, hard cash they saved on all those fuses they once had to buy!

I have a handy dandy Sencore "Fuse Safe" circuit tester which clips in place of a fuse & has a meter to test current draw. It's the HV circuit that's causing issues. It took me some digging to figure out which circuit due to some confusion: Sams has the diagram mislabeled on their drawing as to which is which, plus there seem to have been some running changes as to what Philco specified for each one. I'm not the best diagnostician but I'll pluck away at it...if I keep disconnecting stuff I'm bound to figure it out! Oh, one more thing-when I powered up I let a nice puff of smoke (and a sharp bang) out of something. I was quite concerned, but less so after I spotted the culprit. It seems that yours truly, in a boneheaded move, picked up a 10v capacitor and wired it in where a 50v (IIRC) was called for. Poor little thing didn't stand a chance!
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