Kenwood KT-747L Tuner

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- Brasto
  
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posted
16 years ago

Sat, Apr 26, 2008 7:56 PM

This Tuner does not have any audio output. Probing its ckts with the Oscilloscope showed that at two identical IC's marked 5223 5711 the audio is present at one pin only. It looks like the system is in a MUTE mode or the signal is not switched to the output-jacks. The front- End and Tuning ckts are OK. I cannot find any data on the IC's , schematic of the KT-747L would be very helpfull......... Is there anybody out here who has some knowledge on this receiver? TY Bram

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- Chuck
  
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posted
15 years ago

Mon, Apr 28, 2008 4:49 PM

The ics are probably M5223 op amps. Check the pinout of a NTE778A for the operating parameters. I don't know if this is your problem but Kenwoods of this era had a problem with electrolytic caps shorting out in audio circuits. Chuck

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posted
15 years ago

Wed, May 28, 2008 8:53 AM

Hi Chuck TY for your response, My problem is solved, close examination showed a solderbridge which did not make sense looking at the PCB trace and landings. I removed the excessive solder and PRESTO....the set worked as advertised again. It's owner failed to explain who made the previous repair attempt........