hifi engine

Onkyo TA-2047 tape deck no left channel output

I have a Onkyo TA-2047 tape deck with no left channel output. Level meter for right works fine along with audio output, left channel, dead. Plugging in headphones results in left/right audio but still no movement on meters.

Any suggestions?

Re: Onkyo TA-2047 tape deck no left channel output

1st and most common problem is that the record-playback switch is dirty; a good test is to insert a tape for recording, put deck into record mode several times (to actuate the switch), then test with a pre-recorded tape. Without cleaning the switch the symptom will probably occur again sometime in the future.

Re: Onkyo TA-2047 tape deck no left channel output

Start with the simplest. If you playback a pre-recorded known good tape is the one channel still out? If so, the most common problems are bad head (open circuit), bad head to pc board cable (open or shorted). Bad Record/PB relay (poor contacts in one channel). Bad PB amp (could be a regular op-amp or a dolby IC) before the meter circuit.

Do a visual inspection of the unit first. Look at the cable that goes from head to pc board. Look for burned components or areas of the pc board that are darkened due to damage from heat. Look for poor or broken solder connections. While playing back a tape tap on the record/playback relay with the head of a screwdriver to see if you get any signs of life in the bad channel.

If you still are getting nowhere you will need a voltmeter and probably an oscilloscope to track down where the signal stops. In some cases you may be able to jumper the left and right channels together at the same point in the signal flow to see if you get any output on the bad channel. If so, the problem is before that point in the circuitry. Take a look at the block diagram on page 5 of the Service Manual to see how the signal flows.