hitachi 8290 fast high pitch pulsing

[geoffhartwell]

i have an hitachi 8290 , but its got a real fast high pitch pulsing noise, ive had it apart and ive done all the usual cleaning of switches and record play backs, all in input ports , but if i unplug the deck heads it stops, if i pug the head back in and cross left or right positive with any neg it stops but that only knocks a channel out, any ideas, thanks Geoff

 

[hopey]

Hard to tell what you mean. I think your saying it's an audioble noise and not mechanical?

The first thing I would check is your pinch roller because if it's slipping the take up spool clutch may be cutting in and out which will affect the sound.

 

[geoffhartwell]

it dose it on radio to, but not as loud, its def not the pinch roller, its a real hi pitch beep beep beep real fast to

 

[hopey]

Sounds like a noisey capacitor in the power supply. Have you trying using battery or DC supply?

 

[baddboybill]

I would check the connections on head and also check for pinched insulated head wire

 

[geoffhartwell]

still doing it on dc , head connection is good , even changed the head, it also recorded the high pitch beeping onto a tape , with out pressing record, could it be a bad record playback switch

 

[baddboybill]

Possibly a bad insulated wire to head or maybe a bad ground on deck too