Aiwa ST-R30 tuner with possible faulty HA12016

[stofbj]

Hi,
I have an aiwa ST-R30 with a suspected faulty HA12016 decoder or something around it, When I listen to the signal coming in on pin 2 it sounds fine, but listening on outputs(pin 4 & 7) its muffled and very low output. My voltage measurements are as follows with reference to ground on the chip, which seem all over the place.
Pin1=11.85
Pin2=0.53
Pin3=7.63
Pin4=11.73
Pin5=11.81
Pin6=11.81
Pin7=11.75
Pin8=0
Pin9=3.87
Pin10=0
Pin11=0
Pin12=10.81 (ok for mono)
Pin13=0
Pin14=0
Pin15=0
Pin16=0

Going to take some more voltage measurements around the circuit board, around Q23, anyone have any suggestions?

 

[rayma]

There's USA located, reasonably priced ones here:
https://www.ebay.com/itm/203239819192

 

[stofbj]

HI, I will order one of the chips, My voltages seem fairly wrong according to the diagram, but my supply voltage on pin 1 of 11.85Volts seems ok, I tried to download the datasheets but hard to see what the supply voltage should be, but 12V seems fairly reasonable. I checked all the caps with ESR meter and they all seem ok. Will take a chance on replacing the chip. Do these break a lot?

 

[rayma]

Not likely, but at least they are readily available from a good source in the USA.
Take static precautions when handling and replacing the IC.

 

[stofbj]

ok thanks for advise, yes I will discharge my hands against earth and not touch the pins, no carpet in the house helps too

 

[rayma]

If you have no static mat/wristband, try to keep one hand on the bare chassis.

 

[stofbj]

Got a NOS chip in post from france today for 10 euro including shipping, installed and working perfect, strange how the voltages on nearly all the pins were off due to the faulty chip, must have been fairly messed up what ever happened it

 

[rayma]

Good work.

 

[stofbj]

Thanks for help, did not realize they would be that static sensitive, better safe than sorry anyway.

 

[rayma]

In the winter you can zap about anything with the 10kV static charges.