SONY KV-8100 Portable

[SirVette]

I have a SONY KV-8100 Trinitron 1982 bought new as a backup TV. It has very little use & has never been repaired. It has electronic tuning & 14 presets. It is currently set to all channels in this area & remembers it's settings. Everything works as new except when I checked the tuning function. The tuning lights come on however it's like the the 2 switches (up & down) are not making contact & also Channel clear acts like no contact. These switches have both a removeable cover & an external flip down cover.

The owner manual is currently MIA as I may not have looked at it since 82- it's here somewhere. I have the Sony schematic included w/ the TV.
The Sony schematic shows these 3 switches NO to connect points on
IC 002 CX 760C & a red (on schematic) wire to ground.

Primarily I work on cars including modifications & the electrical. I can pretty much fix anything except electronics at the component level & have never fixed a TV. I have a VOM & soldering iron.

Normally I would shoot some contact cleaner into the 3 switches.
So do you think it just needs the 3 switches cleaned?

Evidently you guys are very good & fixing many TVs w/o the Service manuals. While a Service manual would have limited if any help for me, would it be worthwhile to buy a Service manual for it though probably not needed for this issue?