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JVC TD-W301 dual cassette no output signal?

I picked up a JVC TD-W301 dual cassette (for free) because the transport worked on initial testing. There is no output from the deck though, either through the line outs or the 1/4" stereo jack. Both side work, low and high speed dubbing work, belts seem OK-- the transport mechanism appears to be fine.

When playing either deck (or in synchro dubbing mode) there is no signal at either output and no display on the LED meter above the power on segment. All other front panel indicators work as expected.

I've done the obvious, i.e. applied contact cleaner to the switches, checked the belts, visually examined for damaged parts on the board, adjusted the output pots, etc. I have a service manual for a similar model so have complete schematics. Any ideas where I should start troubleshooting? Any common failure points for decks of this era?

This came from a smoker's house unfortunately, and while it looks clean enough inside some of the other gear I picked up was filthy.


JVC TD-W301 dual cassette no output signal?

Do the heads fully contact the tape when in play mode?
Do the meters function with an external signal input in record mode?

In the first case, the head stack may not be moving freely. Could be a normal lubrication problem.

In the second case, if no audio is registering in play or record, then you may have a power supply problem.

JVC TD-W301 dual cassette no output signal?

Thanks for the reply.

Heads in both wells seem to be contacting tape and transport works. I just fed it an external signal in record mode and still nothing on the meters...appears no audio in either mode. I can engage the dubbing function (both normal and high speed) and the two transports work in sync and will runt through the entire tape in the play well, but still no signal.

Any ideas where to start looking at the power supply? I have a schematic and a DMM. Haven't gone through the board to check all the caps/resistors yet either.


JVC TD-W301 dual cassette no output signal?

I don't have a schematic, but you can look at the amplifier section that the heads are connected to; look for a voltage line (maybe 12 volts) and trace it back to the power supply. There may be a 12 volt regulator IC (3 pins--looks like a transistor). Could be an open IC or just poor connections in the power supply. Could be shorted capacitors; look for burnt resistors.
The power supply will have larger capacitors for filtering and rectifiers or a bridge rectifier.
Edit: I just looked at the 271 manual and it uses an 11 volt supply that is regulated to 7 volts; it may be close to yours. It is fused (2 fuses). You might have a bad zener diode or open regulator transistor, or open resistor. Many circuit boards have voltages listed at the power supply and at wired plugs that connect to other boards. You can make tests at these points.