Pioneer tx-6500 and HA1196

[eizner23]

Picked this tuner up for five bones. No sound from right channel except in AM mode. I have not repaired a tuner before. Poking around I find no signal with scope on Rout pin 5 of HA1196 demodulator. Pin Lout 4 shows signal. Did I get lucky and find the culprit? Looking for confirmation before ordering replacement IC.

Missing pot nut for tuner nob, manual shows 9 with line thru circle. Does that indicate the nut is 9mm?

 

[century tek]

Just quickly scanned your post and you might try deox on the selector switch or at least check out the selector switch. Could be an easy fix.

 

[eizner23]

That was my first thought too but cleaning switch with D5 had no affect in this case.

 

[eizner23]

update on this...
Replaced PLL FM Demod. HA1196 with no cure. Looked at HA1197, many of the test points (pins 2, 7,8,9,10,12) on the pins of the IC were off significantly. Checked components up stream, RF Amp Q1 readings were good, Q2 Mixer was good, Q3 local oscillator was good, Q4 IF amp was good.
Scratching my head...replaced IF amplifier chip HA1197 which is marked with a Pioneer logo with Hitachi HA1197. The unit was dead. Wonder why this didnt work? got chip from reputable source. Put back in original HA1197, unit came back to life and both channels work now.
Apparently I had a cold solder joint, although I inspected with magnify glass before removing HA1197.