Technics RS858 not recording

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Rixter

New member
Joined
Jan 30, 2024
Messages
5
Location
England
Hi my Technics will engage the record button, cartridge will insert and the record light illuminates. But nothing is recorded and the tape does not erase. Tried in 2 ch and 4 ch mode. Removing the case the mechanism seems to operate everything when the record button is pressed. What components tell the head to record rather than play? Thanks Rick.
 
The head is actually switched from being an input to an output In addition, a high frequency bias oscillator is needed to put the signal on the tape.
 
"What components tell the head to record rather than play?"

A record/play switch. Sometimes noted on a schematic as R/P.
I'm not familiar with the model but most often in 8-track decks it is a mechanical switch. A long linear switch mounted on a PCB and driven mechanically by a push of the record button. The contacts inside can oxidize over time. They can often be cleaned. This might not be the problem causing no record, but it is one of the possibilities.

The R/P switch connects the head for playback through the playback circuit. Or connects it to the drive signal from the record circuit for recording. The switch can also have other functions such as enabling meters or lights.
 
With schematic from par4ken and advice from quadsearcher I located the mechanical switch(es), cleaned up with contact cleaner. Hey presto I can now record. Thanks guys.
 
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