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Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
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7th Sep 2015, 4:49 pm | #1 |
Nonode
Join Date: Aug 2007
Location: South Bradford, West Yorkshire, UK.
Posts: 2,571
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Nikko Beta 40 Pre amp
Following the service request in this thread https://www.vintage-radio.net/forum/...d.php?t=119138 Rich brought the preamp up today.
There is a muting relay on the output which turns the outputs on a few seconds after power up. This relay wasn't being turned on. The investigation showed the 12V supply to the relay had a significant 50Hz component due to a short circuit rectifier. Replacing that with a 1N4007 (I have a lot of these diodes) brought the 12V supply back to normal and the correct relay operation. The input switching was checked and after reassembly and rechecking Rich went home a happy man. Keith |
9th Sep 2015, 7:19 pm | #2 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
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Re: Nikko Beta 40 Pre amp
Nice to hear of a happy outcome, Keith. Thanks for letting us know.
N. |