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Old 10-24-2016, 02:14 PM
Zenith26kc20's Avatar
Zenith26kc20 Zenith26kc20 is offline
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Join Date: Apr 2009
Location: New Orleans
Posts: 760
Sencore SG165

Finally got it fixed! First, the piece was intermittant. Try to do an alignment and suddenly no output! Then, no output at all. All functions dead. A bit of troubleshooting (and a lot of disassembly) showed TR316, TR318, TR320 and TR321 bad. Replaced them and started to reassemble the unit... no output but the output jack on the board was active. Remove the cable going to the front jack. Checked output there. Suddenly, output! Then no output. More disassembly! There is a switch and poteniometer between the output jack on the housing and another cable feeding the switch. Touching the cable made output and then none. A bit more digging and the problem that has been driving me nuts for a long time showed itself! The pin on the RCA plug feeding the cable to the output switch had a cold solder joint! When the unit was flexed just right, signal! Then, none. I soldered it! It's been running for hours now! This weekend I am looking forward to playing with an old Harmon Kardon FM tuner and checking it's IF alignment! I know there is a lot of good and bad written about Sencore. Their manual is great for troubleshooting! Loke I said, can't wait!
Oh, I replaced the 2000 mfd with a 220 mfd on the output. It only goes to 400 hz as a low on output. I think I popped the four transistors when disconnecting the piece from a tuner and accidently may have touched B+. 2000 MFD is, to me a bit of overlill. I think even the 220 mfd is too large.
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