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

On Sat, 26 Apr 2008 12:56:40 -0700 (PDT), Brasto
wrote:

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


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

On 28 apr, 18:49, Chuck wrote:
On Sat, 26 Apr 2008 12:56:40 -0700 (PDT),Brasto

wrote:
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

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

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........