TEAC A-4070 from Estate Sale

[RayParkhurst]

I found another TEAC R2R at an estate sale today, this time an A-4070. Overall it looks great, with all the original docs, original accessory box, even the box with spare capstan/lights/reel holders. It powers-up with panel lights, and all the motors seem to work OK, but the capstan pinch roller does not turn or move up/down when changing directions in forward/reverse play. The takeup motors both run "fast". I assume this means I need a new belt, and to lubricate the pinch roller and/or capstan mechanism, correct? I don't see any videos to help me with this like I did with the X-10R. Would appreciate any advice on my simple diagnosis and if there is a repair video available. I downloaded the service manual but it is not very easy to follow, and the instruction manual that came with the deck has no info on belt replacement. Thanks in advance.

 

[SCompRacer]

Does the service manual include the parts list? Some service manual downloads do not include a separate parts list. They can help by showing exploded views but you won't get step by step instructions. Take pics, poke small holes in cardboard for screws and label location to help with reassembly. Use JIS or Japanese Industry Standard drivers. Our Phillips head want to cam out and you can strip the head of a tight screw. You can pick up an inexpensive set of five Hozan JIS drivers on Amazon for ~ $32 which are more than adequate for occasional use. JIS screws have a dimple in the head.

A common issue is hardened grease on pinch roller linkage. #43 in the diagram. If you cannot move pinch roller manually, the grease is dry and frozen. Sometimes you have to heat an arm to get it off, then clean and re-lube. I use synthetic grease on Teac pinch roller arm linkage, some like Lubriplate 105. Reel tables will spin fast with no reels on and tape not routed.

The pinch roller only rotates when in contact with the capstan, which is belt driven. Yes to a new belt, clean and lube. Ensure new belt is routed on correct motor pulley, 60Hz or the smaller motor pulley in US. Operating manual will show basic oiling maintenance. You may need a new pinch roller if old one is hard. Terry's Rubber Rollers in MI can replace the tire for you. The felt brake lining can be hard, or the glue dried out and lining loose on backing straps.

You can try searching youtube for videos of the 4070.

Found one with a quick search, there may be more.

 

[RayParkhurst]

Thanks for the info. The pinch roller was not moving, but with a bit of force it moved down, but it's very gummy feeling. It is still soft and seems in good shape, so I think I can just replace the belt and do some lubrication. The "Spare Parts" kit has an extra NOS pinch roller so I have a backup.

Will report back once I get it running.

 

[ARC Tech-109]

That has to be the best explanation between the USA and JIS Philips differences that I've seen so far. I work with Japanese motorcycles and I run into stripped out philips heads all the time because someone used a substandard or inferior screwdriver on a stuck screw.

You also nailed it on the stuck grease issues with the TEAC decks. I have a A4010S that I've had since middle school (1982) and it got a little groggy when the grease used for the capstan pivot post dried out. Asian grease tends to use more "aromatic" hydrocarbons that evaporate and leave a thick base behind that binds everything up. I use a small glass syringe full of naphtha to drip a small amount to the groggy joints, this softens the thick base grease enough to get moving again so I can disassemble without using a lot of force.

 

[SCompRacer]

@ARC Tech-109 I mention this often and you're the first to second the JIS motion! I learned the hard way many years on a Honda motorcycle. You can feel the difference between a Phillips driver and JIS driver in a JIS screw when applying torque to loosen/tighten. I also have a 4010SU (U=US 60Hz only) that was gifted to me and some of the screw heads had been stripped.

@RayParkhurst Good to hear it's just a lubrication issue! Based on the exploded parts view, the pinch roller should just pull out of the arm. The 4010 is like that.

 

[ARC Tech-109]

Yeah I made a mess of of the carb bowl screws on my Honda CBX Sport and this is where I learned the difference back in the early 90's.

 

[RayParkhurst]

It's actually rare that I find any piece of equipment that has been serviced where the phillips type screws are not messed up. Sometimes the screws are hardened, and those of course hold up better.

It appears this A-4070 has seen little use, with likely only one service by a pro to replace belts around 30 years ago. Docs show it was purchased by a US servicemember in Japan in 1972. The estate sale was family-run, and the sons (all in their 60's) said their dad had OCD and kept all his stuff in perfect shape. When I saw the deck at the sale, my first thought was "where are the tapes" since decks are usually in such bad shape they are not worth buying, but (gasp, wait for it...) the sons told me they took boxes and boxes of tapes to the recycler as they didn't think they were worth anything. And I don't think they were pulling my chain. I was a bit depressed after that.

So, how good or bad is the A4070 going to be once I get it running? Various reviews are mixed, but none speak very highly of it. I do have a new belt on the way as the NOS one in the spare parts box seems likely to crumble if I try to remove it, unlike the pinch roller which seems fresh and soft as new. My only comparison is the X-10R, which I have on a nightstand next to my bed and listen to happily on headphones.