Luxman Amp Problem

[memomat]

Hi,

I wanted to know if anybody could shed some light to my problem.
I have a Luxman R-115 receiver, bought used about 1 1/2 year ago. When turning on it has always turned the tuner section first and a few seconds later the amplifier section would come on (I think it uses a relay) and the output would begin.

Lately (past 2 weeks) there have been 3 ocassions where the amplifier section<goes off shortly (5-15 min) after being on. I have to turn it on and off several times and wait a few minutes before the amp clicks back on (though the tuner section comes on). I can then use it for the listening session without further problems.

What could be causing the problem? Could it be the relay (if it has
one)?

Any suggestions are extremely appreciated.

Thank you.

[EchoWars]

The relays are very reliable devices...the problem is probably elsewhere.

The Lux very likely has circuitry to monitor the DC offset of the amp. If offset is too high, the relay will dis-engage. In the same vein, if offset is very high on start-up, and slowly drifts down, the relay circuitry may be 'waiting' for it to fall before engaging. Measure the DC offset and see what you got (to measure at the speaker terminals, the relay will [of course] have to be engaged).

The more common problem is weak capacitors in the protection circuit, and a weak driver transistor for the relay. The transistor operates as a switch to turn on the relay, and over the years simply gets weak. In this case, you recap the protection board, and replace the driver transistor.

Oh...do NOT cycle power in an effort to force it to work properly. You'll turn a minor problem into a MAJOR one.

[anatech]

Hi memomat,
EchoWars has pretty much got that nailed down. You really should have a technician look at it.

-Chris