Tuner broken in Denon DRA-335R Stereo Receiver

[JS]

Hi,
Everythings works except the tuner - it suddenly broke a few days ago.
When I set the receiver to search for radio stations in its "automatic
tuning mode", its frequency counter just counts continuously through all FM
(and AM) stations and doesn't seem to find any RF signals at all. An
external FM antennae is attached, and has been working in those location for
a year. A walkman in the same room picks up all these stations now. So it
looks like the digital computer portion of the receiver is working fine, but
the RF Front End seems to be broken. I've got the service manual, but didn't
see anything obviously wrong when I poked around with a voltmeter. The
interior was very much dust-covered - I cleaned off much of the dust with
some q-tips. A few days later, i.e., right now, the tuner started working
again. But now I know it's flaky - it didn't work for almost a week.
Any ideas?

thanks,
js.

 

[Jean-Yves]

Hi,
Everythings works except the tuner - it suddenly broke a few days ago.
When I set the receiver to search for radio stations in its "automatic
tuning mode", its frequency counter just counts continuously through all FM
(and AM) stations and doesn't seem to find any RF signals at all. An
external FM antennae is attached, and has been working in those location for
a year. A walkman in the same room picks up all these stations now. So it
looks like the digital computer portion of the receiver is working fine, but
the RF Front End seems to be broken. I've got the service manual, but didn't
see anything obviously wrong when I poked around with a voltmeter. The
interior was very much dust-covered - I cleaned off much of the dust with
some q-tips. A few days later, i.e., right now, the tuner started working
again. But now I know it's flaky - it didn't work for almost a week.
Any ideas?

thanks,
js.

bad contact on some switch (like the power switch... )
it was that on my proton tuner, the power switch has multiple pole, and
one pole was not making a good contact.

check also all the connectors inside.

good luck.

 

[Mark D. Zacharias]

Probably bad solder connections, either at the antenna inputs at the main
board, or in the front-end pack itself. It happens.

Mark Z.

 

[Jerry G.]

The first things to look for are loose or broken connections, cold solder
connections, bad switches, and anything else obvious. The next step is to
verify in the tuner section if the front end RF stage is functioning, if the
local oscillator in the tuner section is working, if the mixer stage is
working, and then on to the IF amplifiers, detector, and then the audio
buffer stages. Some techs like to do the reverse and start at the output end
and work forward. To check the front end you will need a scope, and
preferably an RF test generator set to a reference frequency and level.

If you are not experienced and equipped for this type of service, you would
be best off to send the unit out for service.

--

Jerry G.
==========================


Hi,
Everythings works except the tuner - it suddenly broke a few days ago.
When I set the receiver to search for radio stations in its "automatic
tuning mode", its frequency counter just counts continuously through all FM
(and AM) stations and doesn't seem to find any RF signals at all. An
external FM antennae is attached, and has been working in those location for
a year. A walkman in the same room picks up all these stations now. So it
looks like the digital computer portion of the receiver is working fine, but
the RF Front End seems to be broken. I've got the service manual, but didn't
see anything obviously wrong when I poked around with a voltmeter. The
interior was very much dust-covered - I cleaned off much of the dust with
some q-tips. A few days later, i.e., right now, the tuner started working
again. But now I know it's flaky - it didn't work for almost a week.
Any ideas?

thanks,
js.