UHER Report 4400 Monitor - No Sound

[binspaul]

Hello,

I received an UHER Report 4400 Monitor tape recorder from a friend. The system turns on and all the mechanical functionalities are working correctly (play, fwd, rewind etc). All the 4 speeds are also working correctly.

But, when in play mode, the system is unable to reproduce the sound. Also the VU meters are not moving when in play mode. What could be the possible cause for the issue?

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Best regards,
BP

 

[dotneck335]

Bad playback tape head
Bad playback preamp
Bad power supply

 

[binspaul]

Hi,

The first 2 can be a possible cause. If the power supply is bad, the system will not turn on. So, I am going to check the first 2 options.

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Best regards,
BP.

 

[dotneck335]

Hi, The first 2 can be a possible cause. If the power supply is bad, the system will not turn on. So, I am going to check the first 2 options. -- Best regards, BP.

The playback preamp power supply may be separate. Do the meters indicate audio level when monitoring source? The service manual is available here:
UHER 4000 4200 4400 REPORT MONITOR AV SM Service Manual download, schematics, eeprom, repair info for electronics experts

 

[Kay Pirinha]

Empty tape...
Best regards!

 

[binspaul]

UHER 4400 monitor playback issue.

Hi,

The machine is now able to play but is having some minor issue in playback. The audio output stops suddenly and resumes (a burst is noticed in VU meters and speakers). The burst is almost like tapping the mic while in REC mode.

I checked and seems no issues with the power supply or transport. Can some one help me to identify the possible causes of the problem.

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Best regards,
BP

 

[dotneck335]

Bad coupling capacitor? I would suggest replacing any & all electrolytics in such an old device.

 

[binspaul]

Bad coupling capacitor? I would suggest replacing any & all electrolytics in such an old device.

A possibility.

 

[dotneck335]

What solved the original playback problem?

 

[binspaul]

I don't know actually. Initially when I received the recorder, no sound was coming from it. But one day, I was checking whether the recording works correctly or not and suddenly to my surprise the device started to playback (but with some issues).

 

[Kay Pirinha]

That is, you recorded to tape, then playbacked this tape, and for a sudden the device worked? Remember my post #5...
Best regards!

 

[binspaul]

That is, you recorded to tape, then playbacked this tape, and for a sudden the device worked? Remember my post #5...
Best regards!

Hi,

I am not sure how it started working. May be after passing some current through the circuits for some time, it started. It was in storage for long time (since 1995-till). Not fully functional. Still having some issues with the output amplifier board. It is getting reset (on and off) after few seconds. Need to check and fix this.

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Best regards,
BP