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Sony TC-377 Parts Help

M

Mrnoname

New Member
Hi All,

I've come across a Sony TC-377 tape deck which is cosmetically in superb condition.

I am familiar with these decks and have serviced them before. It looks as if someone was part way through servicing the unit when it was abandoned for whatever reason. All parts are there except for the following (you guessed it)...

Motor Pulley
Rubber idler wheel that goes between the pulley and flywheel.

I've looked everywhere for these parts online but they seem to be near impossible to obtain. Nobody seems to sell reconditioned, second hand or even reproductions!

Can anyone offer any advice or help before I look in to purchasing another deck as spares (seems a waste to do that for just two parts!)


Regards,
Max.
 
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There’s a (supposedly) good used idler tire on eBay from a TC-377 that someone is parting out, perhaps they have the 60hz motor pulley too (assuming you are in the US or Canada). The idler tire may or may not need redressing or a complete rebuild depending on its condition and what was done by the seller. There were a number of speed error correcting pulleys used on these decks from +3 to -3 too so who knows what the original was, but whatever you can get should be close enough.
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Thanks for the reply. I am in the UK so would need a 50hz pulley. Could you link to the idler that you discovered?

Very interesting about the different pulleys, I had no idea. Would you happen to have a part number for the idler wheel? That might help in my search :)

I am wondering if I could get hold of a motor pulley temporarily off of another deck if I could look at getting one machined. No doubt it would be expensive though. I wonder how a plastic 3D printed part would fare... I suspect it would wear down quickly and not be accurate enough?

If I can't obtain the parts I think my best option would be purchasing a poor conditioned deck as a parts unit. Something about parting one out feels wrong though.


Regards,
Max.
 
Sony idler for that deck is X-34720-33 and I believe it’s the same one used in many of them like the TC-353 etc. Since you’re in the UK you will need both capacitors for the motor phase correction too (though I’m sure you already know that). Interesting thought regarding the 3D printing, not sure how that would work. Guess it would depend on the hardness of the material it’s printed from. These decks are common as water here in the US, not sure about the UK but the 366 and 377 were extremely popular sellers here. Not sure I can link the eBay sale but I’ll give it a shot, it’s in the US though so the pulley (if he has one) won’t do much good. https://www.ebay.com/itm/254885778421

Agree about not liking to part them out. Every parts machine of these I’ve ever had I ended up restoring lol!
 
Thanks audiojones. The motor run cap is present, as is virtually every other part as far as I can tell. The odd washer and E clip was missing but I have been able to replace those fairly easily. The only major components missing are the idler and the pulley. Thanks for the link to the idler. Good spot.

I might delve in to having an existing motor pulley scanned and 3D printed or machined. I imagine that if you could get an accurate CAD file of the pulley the possibilities would be endless.


Regards,
Max.
 
You’re welcome and good luck with it! Do replace the motor run capacitor when you get everything together, they are very well known for going bad in all Sony single motor machines. I’ve lost count of how many I’ve had to replace over the years, nearly every one that’s come through here has needed one (and that’s quite a few). You will need a 2uf cap for 50hz operation (the stock cap is a 1.5uf and the 50hz switch adds .5uf for a total of 2uf). There are very inexpensive and reliable poly motor run caps that will do the job even better than the original.
 
Thanks, out of interest how would I definitively know if the motor run capacitor was bad? Would it be a case of the motor running slow? Is there an easy way to test the cap?

Could you link me to an example quality replacement?


Regards,
Max
 
Mrnoname said:
Thanks, out of interest how would I definitively know if the motor run capacitor was bad?
Click to expand...

Easy...if it’s a Sony single motor machine it’s bad lol! When it fails the motor will run hot, start to slow down as if the idler is slipping and often it will stall out altogether. I’ve run across machines that people have continued to use in spite of the fact that it’s running slower, that’s when the run capacitor overheats and spews wax all over the inside of the machine (really stinks too). I wouldn’t be surprised if that’s why yours was taken apart in the first place, often speed issues blamed on the idler turn out to be the run cap. They’re not worth testing as they usually test ok but fail under load anyway. If it’s the original run cap I would strongly suggest preemptive replacement; it’s inexpensive, very easy to do and the original is pretty much guaranteed to fail. I don’t generally recommend blind replacement of components but this is one case where I do.

I’ve always used poly motor run caps with the mounting tab and lead wires, that makes it nice and easy to do a professional job and mount the cap to the chassis instead of using wire ties to hold it down. In the case of your Sony you can just remove the 50/60hz switch plate, wiring and hardware and then just mount a 2uf poly cap in there if it won’t be used at 60hz. The two wire leads from the new cap get wire-nutted to the leads from the deck that went to the old cap, no polarity issues to worry about with poly caps. Here’s a link to what I’m talking about, been using them for years with great success.
 
Yep, that’ll do it, the 450vac is actually better than 250 volt rating. I’m not sure how Sony equipped machines for sale in the UK but if you have the style with a 50/60hz switch you can remove all that and set it up for 50hz only.
 
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