drmini Posted December 21, 2015 Posted December 21, 2015 Years ago, I dry stored my 331 receiver as we went surround sound. Now that I have another use for it, it doesn't work. There seems to be no power from the power supply, no lights come on. A quick look by an ex-TV tech mate showed the 4 diodes on the power board are now open circuit. There are 3 fuses, none are blown. I have downloaded a 331 service manual, but I'm not into electronics repair. Can someone here please recommend a repairer? I don't want a concours restoration, I just want it going again. Cheers, Kevin
skippy124 Posted December 21, 2015 Posted December 21, 2015 Hi Kevin, Did your ex TV tech friend replace the diodes? It is unusual for all four diodes to go open. It could be the amplifier module has a problem, and if so these are not easy to get. I would be happy to have a quick look at it, let me know if you want to call in. I am located in Guildford Cheers John
drmini Posted December 21, 2015 Author Posted December 21, 2015 Thanks John, can you please msg me your address and I'll drop it in. I'm not far from there. Diodes not replaced yet. My friend is in his mid 70s (and me too almost), it's been a zillion years since he had any repair gear. I had to loan him my meter to check with! Cheers, Kevin
N1TRO Posted December 21, 2015 Posted December 21, 2015 Good luck with the repair, good thing about older amplifiers is they are more simple!
drmini Posted December 22, 2015 Author Posted December 22, 2015 All fixed now! Was hardly anything wrong.... I would sincerely like to thank Skippy124 for his time and trouble today, he's a legend. Cheers, Kevin 2
skippy124 Posted December 22, 2015 Posted December 22, 2015 Hi Kevin, It was nice to meet you today, and it was fortunate that the 331 was an easy fix. Cheers John
niss_man Posted December 22, 2015 Posted December 22, 2015 What ended up.being the cause of the problem?
N1TRO Posted December 22, 2015 Posted December 22, 2015 What ended up.being the cause of the problem? Id like to know to
drmini Posted December 22, 2015 Author Posted December 22, 2015 (edited) Well.... It wasn't really dead, was it....! I had stored it 10 or 15 years, when I plugged the power in a year or so ago there were no lights on, so I assumed it had carked it. Fast forward to last week, I dragged it out, my mate looked at it but didn't power it up as he thought with no speakers it might blow something. He used my meter on the diodes and pronounced them open, so that's when I jumped on the forum. Repairs that John did today- Had a good look inside, then plugged 2 speakers and FM antenna in and away it went, Changed both the blown front panel lamps, Tested power board output voltage- found it a bit high (it was shipped with 220V tapped when new) so he changed it to 240V. Cleaned the front panel up, sprayed the control pots, put it back together. Good to go. This is to play my old vinyl again in the bedroom. I'll plug my antique Thorens TD160 and Wharfedale Denton 2 XPs in tomorrow and give it a blast. [edit] I dragged my old Sennheiser HD414 headphones out of the cupboard and the foam pads had self destructed. Surprise (not). For anybody that buys these things, I found Sennheiser Australia the cheapest by far. $7.52 a pair, some eBay places wanted 2x this. Post $10. Edited December 22, 2015 by drmini 1
drmini Posted December 24, 2015 Author Posted December 24, 2015 (edited) Update- It's up and running fine. For a small system in a small room, I'm impressed. The Wharfedale Denton 2 XP speakers cost me $50 the pair 5 years ago, I'd never hooked them up. The Thorens TD 160 + Shure V15-111 is still OK. I've also plugged my old Sansui D-350M direct drive cassette deck into it, it's working fine too after 10+ years of non-use. I like Sansui stuff. Edited December 24, 2015 by drmini
drmini Posted December 26, 2015 Author Posted December 26, 2015 (edited) I spoke too soon...! FM & AM tuners worked fine for a day, then their signal levels dropped, then both disappeared. Phono & tape inputs still work fine. Skippy now has it back on his operating table to see what is the problem. [edit] Problem found was a crook transistor in the power supply, now fixed. [edit 2] All good now, running well. Thanks Skippy! Edited December 28, 2015 by drmini
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