Please help me diagnose the following problem, or suggest what the
problem may be.
Any and all suggestions and advice greatly appreciated!
Respond to the newsgroup only. Thanks!

I have Alpine cassette radio TDA-7548 in 1999 Subaru Outback. Installed
it myself in 1999, worked flawlessly till now (except for occassional
bad contact of the removable faceplate).

The unit went dead a few days ago. When I turn the power on, and the
unit "source" is radio, I hear a faint noise from the speakers. The
noise can be controlled by the volume knob -- at 0 volume, the noise
ceases, and increases with adding volume. No other sound whatsoever. The
station presets and tuning works normally, I can see the frequency on
the display, but switching the stations does not chnage the noise sound.

When I switch the source to "tape", the noise stops completely -- no
sound at all.

When I switch the source to"CD" ( I have an AI-Net changer attached), I
can see on the display that the CD is playing (showing the track and
time counter), but no sound comes out.

So, the noise is heard only on radio, the controls work fine, and there
is no sound.

A local store employee suggested that the amplifier may be dead.

I would like to know what the problem might be, and if it's worth
sending the unit for repair to Alpine. I was told it's about $80-$100 to
fix it.

I also considered buying a new deck, but there don't seem to be any
available Alpine cassette radios compatible with AI-Net (I'd like to
keep my CD changer).

Thanks for help!

AS in Seattle

It could be the radio, the amp if there is a separate amp or a bad speaker.
I would disconnect your speakers and reconnect them one at a time until the
problem comes back. I'll bet it's a bad
speaker(s).


Paul Vina



wrote in message ...
Please help me diagnose the following problem, or suggest what the
problem may be.
Any and all suggestions and advice greatly appreciated!
Respond to the newsgroup only. Thanks!

I have Alpine cassette radio TDA-7548 in 1999 Subaru Outback. Installed
it myself in 1999, worked flawlessly till now (except for occassional
bad contact of the removable faceplate).

The unit went dead a few days ago. When I turn the power on, and the
unit "source" is radio, I hear a faint noise from the speakers. The
noise can be controlled by the volume knob -- at 0 volume, the noise
ceases, and increases with adding volume. No other sound whatsoever. The
station presets and tuning works normally, I can see the frequency on
the display, but switching the stations does not chnage the noise sound.

When I switch the source to "tape", the noise stops completely -- no
sound at all.

When I switch the source to"CD" ( I have an AI-Net changer attached), I
can see on the display that the CD is playing (showing the track and
time counter), but no sound comes out.

So, the noise is heard only on radio, the controls work fine, and there
is no sound.

A local store employee suggested that the amplifier may be dead.

I would like to know what the problem might be, and if it's worth
sending the unit for repair to Alpine. I was told it's about $80-$100 to
fix it.

I also considered buying a new deck, but there don't seem to be any
available Alpine cassette radios compatible with AI-Net (I'd like to
keep my CD changer).

Thanks for help!

AS in Seattle

I would guess it may be a bad amp.
Alpine has one cassette deck left in there line of products. You could go
with that (TDM-7582) and get a KCA-130B (I think this is the model number)
adaptor so that you can still utilize your CD changer.

"Paul Vina" wrote in message
news:lqiqb.87693$ao4.268727@attbi_s51...
It could be the radio, the amp if there is a separate amp or a bad
speaker.
I would disconnect your speakers and reconnect them one at a time until
the
problem comes back. I'll bet it's a bad
speaker(s).


Paul Vina



wrote in message ...
Please help me diagnose the following problem, or suggest what the
problem may be.
Any and all suggestions and advice greatly appreciated!
Respond to the newsgroup only. Thanks!

I have Alpine cassette radio TDA-7548 in 1999 Subaru Outback. Installed
it myself in 1999, worked flawlessly till now (except for occassional
bad contact of the removable faceplate).

The unit went dead a few days ago. When I turn the power on, and the
unit "source" is radio, I hear a faint noise from the speakers. The
noise can be controlled by the volume knob -- at 0 volume, the noise
ceases, and increases with adding volume. No other sound whatsoever. The
station presets and tuning works normally, I can see the frequency on
the display, but switching the stations does not chnage the noise sound.

When I switch the source to "tape", the noise stops completely -- no
sound at all.

When I switch the source to"CD" ( I have an AI-Net changer attached), I
can see on the display that the CD is playing (showing the track and
time counter), but no sound comes out.

So, the noise is heard only on radio, the controls work fine, and there
is no sound.

A local store employee suggested that the amplifier may be dead.

I would like to know what the problem might be, and if it's worth
sending the unit for repair to Alpine. I was told it's about $80-$100 to
fix it.

I also considered buying a new deck, but there don't seem to be any
available Alpine cassette radios compatible with AI-Net (I'd like to
keep my CD changer).

Thanks for help!

AS in Seattle

What is the model number of your existing changer?

but there don't seem to be any available Alpine cassette
radios compatible with AI-Net (I'd like to keep my CD changer).

Thanks everyone for helpful suggestions!

My changer is CHAS-614, which should be M-Bus compatible, so the suggested
replacement combination TDM-7582 and KCA-130B should work.

I did not have time to check the speakers & wires, but interestingly, the
radio came back intermittently for a few seconds at a time. Sometimes, when
I turn it on with its Power button, it plays clearly for 2-6 seconds, and
then it goes quiet (just the noise) or starts completely garbling the sound.
Any more ideas?

Thanks!

Someone correct me if I'm wrong....but....

the 614 doesnt have a selector switch next to the
eject button, to allow for m-bus operation.

You will find this switch, if its there, by sliding open
the cartridge door, and finding it under the eject button.

the A in the model number means its an AI net changer.
I bet the switch is not there, and therefor will not work
with an M-bus radio.





Thanks everyone for helpful suggestions!

My changer is CHAS-614, which should be M-Bus compatible, so the suggested
replacement combination TDM-7582 and KCA-130B should work.

I did not have time to check the speakers & wires, but interestingly, the
radio came back intermittently for a few seconds at a time. Sometimes,
when
I turn it on with its Power button, it plays clearly for 2-6 seconds, and
then it goes quiet (just the noise) or starts completely garbling the
sound.
Any more ideas?

Thanks!

Miraculously, the radio came back to life after I removed the left rear speaker:
While checking the wires and everything, I noticed that the left rear speaker
sounds much weaker than the right rear one. I unplugged it, and all the garbling
and noise disappeared. The radio/CD/tape now plays fine on the front speakers.

I thought that it was the left rear speaker that caused the problem, so I had it
checked at a local car audio store, and they confirmed that it was fried. I
bought a replacement pair of rear speakers and thought that my problem was
solved. However, when I connected the new speaker to the left rear channel, no
sound came out (the old rear right speaker still plays fine). While attaching
the new speaker, I noticed little sparks when the wires touched the connectors
on the speaker. So, there must be some current going through the wires, however
the channel is silent. I wonder if the channel in the amplifier is bad after
all, and fried the old speaker initially.

Any suggestions how to diagnose this or determine if the radio/amp is at fault?

Any help greatly appreciated. Please respond to the group. Thanks!

AS

Well, I was right about the speaker. Now you need to check the speaker
wiring and make sure it hasn't rubbed through and shorted to ground
anywhere. Other than that it could be the amp channel but that's rare.
Usually it'll activate the protection cicuits or kill all the outputs.


Paul Vina



wrote in message
...
Miraculously, the radio came back to life after I removed the left rear
speaker:
While checking the wires and everything, I noticed that the left rear
speaker
sounds much weaker than the right rear one. I unplugged it, and all the
garbling
and noise disappeared. The radio/CD/tape now plays fine on the front
speakers.

I thought that it was the left rear speaker that caused the problem, so I
had it
checked at a local car audio store, and they confirmed that it was fried.
I
bought a replacement pair of rear speakers and thought that my problem was
solved. However, when I connected the new speaker to the left rear
channel, no
sound came out (the old rear right speaker still plays fine). While
attaching
the new speaker, I noticed little sparks when the wires touched the
connectors
on the speaker. So, there must be some current going through the wires,
however
the channel is silent. I wonder if the channel in the amplifier is bad
after
all, and fried the old speaker initially.

Any suggestions how to diagnose this or determine if the radio/amp is at
fault?

Any help greatly appreciated. Please respond to the group. Thanks!

AS

Thanks Paul! Any suggestions how to easily check that the speaker wires are
getting the proper signal at the end? I can see disconnecting the speaker wires
at the radio end, and checking that neither is shorted using a battery and a
bulb. But if they are not shorted, how can I easily tell that it's amp channel
that's faulty? Connecting the speaker right at the radio output wires?

One other weird thing -- the whole problem started with the following symptom:
One morning I opened the car, and without even putting the key into ignition
(i.e., not turning on the power to the radio) I already heard the faint noise
coming from the speakers. It eventually stopped when I turned the radio on and
off couple of times, but it's not clear to me why the speakers made the noise if
the radio was off and without power!

AS

Paul Vina wrote:

Well, I was right about the speaker. Now you need to check the speaker
wiring and make sure it hasn't rubbed through and shorted to ground
anywhere. Other than that it could be the amp channel but that's rare.
Usually it'll activate the protection cicuits or kill all the outputs.

Paul Vina

Miraculously, the radio came back to life after I removed the left rear speaker:

While checking the wires and everything, I noticed that the left rear speaker
sounds much weaker than the right rear one. I unplugged it, and all the garbling

and noise disappeared. The radio/CD/tape now plays fine on the front speakers.

I thought that it was the left rear speaker that caused the problem, so I had it

checked at a local car audio store, and they confirmed that it was fried. I
bought a replacement pair of rear speakers and thought that my problem was
solved. However, when I connected the new speaker to the left rear channel, no
sound came out (the old rear right speaker still plays fine). While attaching
the new speaker, I noticed little sparks when the wires touched the connectors
on the speaker. So, there must be some current going through the wires, however
the channel is silent. I wonder if the channel in the amplifier is bad after
all, and fried the old speaker initially.

Any suggestions how to diagnose this or determine if the radio/amp is at fault?

Any help greatly appreciated. Please respond to the group. Thanks!

AS