Where can I find a repair manual to replace belts on my Onkyo Stereo Cassette Tape Deck TA-630d

Take it to a local audio repair engineer. There may be a broken drive belt. Or take the case of and take a look.

NEW 2 Replacement BELT SET* ONKYO TA-RW414 TA- ...

West Coast Belts https://westcoastbelts.com > Electronics

*NEW 2 Replacement BELT SET* ONKYO TA-RW414 TA-RW400 TA-RW470 DUAL CASSETTE Player ; Easy Returns. Quick & Hassle Free ; Dimensions, 6 × 6 × 1 in ; Compatible ...
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https://www.google.com/search?q=Onkyo+TARW470+tape+deck

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https://www.idealspace.net/onkyo/onkyo-surround-sound-systems

Stretched belt, or worn rubber tyres... you need to open it up and replace.

cassette tape stops 5 seconds

Sounds like the cassette tape itself is too tight to play, try fast forwarding or rewinding the tape in the deck all the way to the end of tape several times before trying to play. This may solve the problem

HELLO

By the fault you describe this sounds very much like a belt problem. Take the case off the deck and check the belt(s). Some decks can use more than one belt and you need to look at their condition.

Are they too slack around pulleys maybe? Belts don't last forever and I'm not too sure of the age of your deck. But personally, I would change them all.

Make sure the tape path is clean as well, clean heads, pinch roller and capstan.

i bought some today from **** smith electronic store , i paid $7.97 for a pack of ten assorted sizes

The best cleaner for heads is Servisol Video 40. You can get it from Maplin's UK or Amazon.

Hi Chris..

It's not worth repairing. I would find something else in good condition

Sounds like the belt that drives the capstan is too slack or decomposed, The capstan(s) which are connected to a geared flywheel, also drives the transport mechanism. There can also be tarnish on the sensor leaf switches, preventing contact. You might try to repair it yourself but, it is not an easy or simple job