No sound out of the left channel? Soldering iron time! Sony K661S (another one!) 

Use the calibration feature with the bias and volume dials at 12. It shouldn't be far off correct with a good type 1 tape in if it's setup properly.

Certainly is, the calibration stage is about the same. No dry solder on your deck though!

The interesting thing is although it also has Dolby S it wasn't part of the plan when designing the decks. That's why some of them shipped with a huge Dolby S sticker on them. People give them a bit of grief and call them old clunky. Their loss.

@@pwrestoration For me, it’s much like Dolby C, I would try it on a few tapes but when recording for myself, always using Dolby B. It would be great having the calibration mode (even if it doesn’t support calibrating the left and right level separately) rather than using what I use on a two head Denon DRM-550 connected to an oscilloscope and having test tones ran into it.

don't hang about prices of these are going up fast

This is interesting!

No audio at all on the left channel, including on the display bars would need tracing from the head using an oscilloscope. You may be lucky and find a component failure that isn't the playback head, but there could also be a point of failure at the solder points for the head plug on the mainboard.

Thank you for the reply. You have given me some pointers. I don't have a scope, but I did a continuity test on the heads at the connector end; they are showing 310 and 320 ohms (or was it 210 and 220?). It was a few weeks ago that I checked that. I will check the plugs and solder joints.@@pwrestoration

Thanks I'm really trying to get my video quality up, with a tripod. I think lighting is my next push to improve. Thanks for the positive comments! Paul

It's the bias pots that need adjusting. I would avoid the FE tapes the decks don't like them. Try a Sony type 1 and see how it does

Also I believe it's not the spindle jumping around during playback, it's the actual hubs slipping around the spindle like the teeth are slipping and causing the bumping around... Any advice would be most appreciated.

Yes you don't even need to remove the transport, just the black plate with the light on, and then pull the reel off. There isn't anything to go wrong really though

are you aware of the supply reel bumping around on these decks?. in most cases, it doesnt affect the audio, but i have noticed spikes in the Wow & flutter on some cassettes@@pwrestoration

btw, well done for getting £176 for this deck on ebay, i was watching the bid over the last few days

@@matthewchakera8366 ​@matthewchakera8366 unfortunately, again, gonna have to relist it. eBy is turning into a circus at the moment. Guy didn't pay.

I can confidently say now I am a UK based expert in these decks. I service or repair one at least every week, mostly through emails or context through here and eBay. In total I think I've repaired or serviced maybe 60 of them in total, have two myself and a box full of spares. I don't think I'll be doing more videos of this unit type for the channel (simply as I have about five now) but the convenience of them now being my bread and butter and being able to film the work is easy. Some clients don't want their gear recorded. Don't panic though, I have two Nakamichis and a JVC video coming very soon!