Pioneer KP-500 Supertuner, only one channel has output to the speakers

[johnobub]

I have a Pioneer KP-500 Supertuner and only one channel has output to the speakers. I'd like to get it working again. I have the service manual but I was wondering if someone on here could identify what to check or replace first.
Thanks.
John

 

[DigitalJunkie]

I'll take a guess at it being the audio amplifier IC. Look up the datasheet for the amplifier IC it uses,and see if there's signal going in to the input pins. If not,the problem is somewhere further back.

 

[Perry Babin]

Some of these go for very high prices on eBay. One went for $500 (new in box). They regularly go for $250+ in good working order.

 

[johnobub]

I'll take a guess at it being the audio amplifier IC. Look up the datasheet for the amplifier IC it uses,and see if there's signal going in to the input pins. If not,the problem is somewhere further back.

Are you talking about checking the input at the AN214 or the HA1137 ?
Here is the manual.
http://retrocaraudio.servehttp.com/...SilverSeries/Pioneer KP-500 ServiceManual.pdf

 

[Perry Babin]

The link is dead (for me anyway).

The output IC is likely clamped to the outer casing or to a relatively large piece of metal. The HA1377 and 1398 were commonly used. The attached photo should help you find it.