Dear people,
I suddenly have a problem with my beloved Sony STR-DB 840 QS receiver.
One of the front speakers (left) will only start after 5-15 minutes.
I have already opened the receiver and have taken out the various circuits. Soldering of the plates viewed, but not seen crack or bad connections.
I measured the wiring / plugs from the "motherboard" to the speakers and they seem to be ok.
I hear a relais giving a click when I turn on the receiver.
With the speaker selector A / B / AB / off I hear a relais click.
But I totally do not know where to start to solve the cause.
Does anyone have an idea where I should search first?
With greetings Frits
I suddenly have a problem with my beloved Sony STR-DB 840 QS receiver.
One of the front speakers (left) will only start after 5-15 minutes.
I have already opened the receiver and have taken out the various circuits. Soldering of the plates viewed, but not seen crack or bad connections.
I measured the wiring / plugs from the "motherboard" to the speakers and they seem to be ok.
I hear a relais giving a click when I turn on the receiver.
With the speaker selector A / B / AB / off I hear a relais click.
But I totally do not know where to start to solve the cause.
Does anyone have an idea where I should search first?
With greetings Frits
Since nothing major seems to be amiss, I'd guess it's either
a) bad output relay contacts (not an unusual fault in older amps)
or
b) a problem with the muting circuit for that channel (possibly a leaky electrolytic).
Problematic relays can be identified by tapping them with an insulated screwdriver handle and listening for noises in the loudspeakers.
Another indication would be whether the "wakeup time" depends upon output level at all. Can you let the amp sit for, say, half an hour with nothing at all playing and then get a perfectly fine left channel? If that channel is still dead, it's probably the relay.
a) bad output relay contacts (not an unusual fault in older amps)
or
b) a problem with the muting circuit for that channel (possibly a leaky electrolytic).
Problematic relays can be identified by tapping them with an insulated screwdriver handle and listening for noises in the loudspeakers.
Another indication would be whether the "wakeup time" depends upon output level at all. Can you let the amp sit for, say, half an hour with nothing at all playing and then get a perfectly fine left channel? If that channel is still dead, it's probably the relay.
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