Sony TC-377 Reel to Reel Restoration - Need Feedback

Marcham93

Marcham93

Active Member
Afternoon, everyone.

After discovering that the Sony TC-377 Reel to Reel machine does in fact work, I am excited to start tuning it up and having it back to its prime state. I have never done this before, so I want to lay out a few of my plans below and, hopefully, the more experienced can let me know if I'm going down the wrong (or right) path.

For starters, the volume knob on the side crackles a bit when turned. I went out and picked up an electronic contact cleaner. After removing the plastic knob, I believe all I must do is spray the potentiometer and turn it back and worth a few times to get it working then let it dry (for how long?). I want to make sure I am not damaging the unit when doing this procedure.

The second operation I have is to lubricate certain parts. In particular, the speed selector knob on my unit is very hard to turn. I have seen videos of this unit online and it appears that the knob should click between the three settings in an easy fashion. I intend to open the unit and lubricate the mechanism while also checking for any misaligned gears, etc. I picked up light machine oil to do the job, but I'm not sure how to remove the old gunky oil from the machine.

Lastly, something I don't need help with, I will be replacing the belts as they are currently slipping and are very loose.

I welcome any experienced advice and will keep this post updated with my progress.

Thanks, all!
 
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Spray the contact cleaner into the actual control housing from inside the deck, not through the shaft up front. You then have to vigorously work the control back and forth while it's wet with the contact cleaner to help wipe the corrosion and dirt away.

You should also clean the record slide switches (two long switches mounted on the record board, they are the ones operated by the two individual record buttons). All of your signals pass through these switch contacts and they are often the cause of all sorts of trouble. Thoroughly dry all contact cleaner with compressed air before powering it up.

The mechanism lever should click to all positions easily and hold there when a tape is loaded. With no tape under the head block it should spring back to the stop position no matter where you place it. There will probably be a lot of hardened up grease on the linkages here, so take your time and carefully clean out all of the old lube with a solvent such as alcohol, lighter fluid, WD-40 or some other kind of plastic safe gum cutter. Be careful not to get any on the meters and try not to get any on the circuit boards. Chase it with compressed air to get all the crud out of the linkages and use a little sewing machine oil on all of the pivot points, white lithium grease on anything that slides.

Be careful not to get any grease or dirt on the flywheel or the idler wheel. The idler will probably need to be resurfaced with some emery cloth and rubber rejuvenator to get its grip back. These are surprisingly good little tape decks when they are all fixed up and dialed in. Most of the information in the TC-366 manual applies to the TC-377 especially the mechanical stuff.
 
Hi Michael -

I went through this process a couple years ago and was rewarded with a great tape deck that I use several times a week.

One thing that threw me briefly was removing the front panel (so I could get to the mechanism). It turns out there are a couple screws disguised as the pins onto which the cover for the heads fits onto. Those screws have a 5 mm hex 'head' - I went to Home Depot and bought a 5mm x 1/4" deep socket to easily remove those screws! And when you're re-assembling the machine don't tighten those screw to tight - just beyond finger tight is probably adequate! Their small size can easily break off if to much force is applied!

Good luck and enjoy the results!

Dirty Al
 
Thanks everyone, I really appreciate the advice. Once I go home tonight I'll start taking apart the machine and seeing if I can fix the parts that need to be lubricated. Also I'm going to try and work on the crackling knows and switches. The belts should arrive by the end of this week so hopefully I can have this machine up and running for the weekend. If I have any questions I'll be sure to ask. All your help is seriously appreciated!
 
Update: Alright, so I replaced all the belts and the fast forward and rewind functions work great, along with the time counter. I also was able to lubricate behind the head mechanism properly so that the selector switch now works and will auto shut-off when the tape ends. As for the speed selector, I've done a lot of lubricating and spraying of it with contact cleaner and it has helped a bit, but is still a bit difficult to turn (although I could live with it).

audiojones said:
The idler will probably need to be resurfaced with some emery cloth and rubber rejuvenator to get its grip back. These are surprisingly good little tape decks when they are all fixed up and dialed in. Most of the information in the TC-366 manual applies to the TC-377 especially the mechanical stuff.
Click to expand...

This is the one issue that I believe I am having as when the unit plays it seems that the idler wheel is completely slipping and thus the machine won't play. Can you please explain this process a bit more? Do I attach emery cloth to the wheel and then add the rubber restoration spray? Bit confused... or do I sand it down first and then add the restoration spray?

Thanks again, all.
 
What I do is to remove the idler wheel from the machine and put it in a drill press. While it's revolving I gently press fine grit sandpaper evenly against it to get that layer of hardened rubber off of the surface. It's important that you do this evenly and gently, don't get it out of round. Then when the rubber edge is nice and supple I'll hit it with rubber renewer (on a cotton swab) to really get it to grip nicely. While the idler is out of the deck it's a great time to really super-clean the flywheel and motor pulley with alcohol. If the motor pulley and capstan flywheel are squeaky clean and the pinch roller is nice and supple that machine will come up to speed instantly.
 
Oh, one other thing...the linkage that carries the idler wheel is a two piece articulating linkage and both joints must be totally free so that it can snap into place between the motor pulley and the flywheel. It's not enough if it just pivots into place, the end of the linkage needs to free to flip into position once the main linkage moves it close to the flywheel. If the end of the linkage isn't pivoting (common problem) then you will have the same symptoms with drive speed that you are describing. Since you said your speed selector is still hard to move it sounds like you may still have a problem here.
 
audiojones said:
What I do is to remove the idler wheel from the machine and put it in a drill press. While it's revolving I gently press fine grit sandpaper evenly against it to get that layer of hardened rubber off of the surface. It's important that you do this evenly and gently, don't get it out of round. Then when the rubber edge is nice and supple I'll hit it with rubber renewer (on a cotton swab) to really get it to grip nicely. While the idler is out of the deck it's a great time to really super-clean the flywheel and motor pulley with alcohol. If the motor pulley and capstan flywheel are squeaky clean and the pinch roller is nice and supple that machine will come up to speed instantly.
Click to expand...

I cleaned everything up and sanded down the idler, although I don't have rubber renewal, everything works great now!

audiojones said:
Oh, one other thing...the linkage that carries the idler wheel is a two piece articulating linkage and both joints must be totally free so that it can snap into place between the motor pulley and the flywheel. It's not enough if it just pivots into place, the end of the linkage needs to free to flip into position once the main linkage moves it close to the flywheel. If the end of the linkage isn't pivoting (common problem) then you will have the same symptoms with drive speed that you are describing. Since you said your speed selector is still hard to move it sounds like you may still have a problem here.
Click to expand...

And yes. I think it has to be taken out and completely cleaned. I might old off on that for a bit as I've been oiling it and it gets easier to turn everyday. The idler mechanism needs a new spring as the current one is a bit weak, but for now it operates good enough for me.

---

New issue, I apparently moved something because the pause mechanism is no longer working. The pinch roller moves away, but the fly wheel keeps spinning - so nothing actually stops. Any ideas on this? I included a short YouTube video for more visuals. I can't seem to figure out how to get it working. Probably a small piece that I moved, but I can't figure out what.


Thanks, all.
 
That's actually how the pause control works. It doesn't stop the flywheel or the take up clutch under the take up reel table, all it does is lower the pinch roller and apply the brake on the feed reel. Make sure the linkage is properly attached to the feed reel brake mechanism and try it out with a tape loaded. If needed the pause linkage adjustment is the same as outlined in the TC-366 manual at HiFi Engine.
 
Evening.

I've been working the last few days and also planning a move to a new house, so it has been a bit crazy. Anyway, an update on what I've done: The rewind, fast forward, and play modes work perfectly after new belts and cleaning, the counter now works with a new belt, the tape shutoff mechanism has been lubed and works again.

The two parts I still need to fix are the pause mechanism and the smoothness of the tape speed selector mechanism. I believe I found out what is wrong with the pause lever (it seems to be a spring in the unit that is simply too loose). As for the tape speed selector: the knob works smooth again, but the idler wheel mechanism doesn't move smoothly back and worth. It works with a few jiggles of the selector dial, but probably needs to be taken apart. I can't seem to just lube it while in the mechanism.

On a last note. I tried recording, but it seems the erase head does not function at all. The record head works, but it won't erase what was previously on the tape. I'm going to check the wiring, but I assume it might just be the head itself unless anyone has any ideas.

Thanks, all. And especially you, Matt.

-Michael
 
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Glad you're making progress! Regarding that erasing problem, is it possible that the tape you're using was recorded on a different machine with a different format? Your Sony is what's known as a 1/4 track stereo deck, meaning that 1/4 of the tape is used for each track (left & right side 1, left & right side 2). If you try to record over a tape that was recorded on a 1/2 track mono deck (typical of very old tube recorders or small portable machines) or a full two track deck (typical studio and broadcast recorders) your Sony's erase head won't line up with the previously recorded material and it will always play through. That's why it is always best to bulk erase old used tape before recording on it, you never know what machine was used to record on it.

Also make sure the heads are 100% clean, no oxide or crud on them at all. Finally make sure the back tension is set properly, if there isn't a slight drag from the feed reel during play / record then the tape will pull away from the erase head since it's the first one in the line. The procedure should be in the TC-366 manual for that adjustment if needed. Since you are having pause issues this might be related because the back tension (like the pause function) relies on the supply reel brake linkage functioning properly.
 
Alright, so I finally got almost everything working! I had to purchase a few new springs for the machine as the older ones had worn out. Now, erasing, recording, and playing all work great! I also ran over everything with a demagnetizer and it sounds quite nice. As per your comment above, Matt, sadly I don't have a bulk eraser, but maybe one day in the future.

The last issue that remains is the speed selector which sticks a bit when you increase the tape speed. I've tried using light machine oil and simple contact cleaner; oddly, the light machine oil doesn't seem to do much, but the contact cleaner helps a bit. Not sure if I am using the wrong solution or if I just need to really break the machine down to the core.

Everything is looking good though!
 
Yep, it's petty hard to get all of the hardened grease out without total tear down unfortunately. If everything is working properly I'd just enjoy it for now, sounds like you're pretty busy these days.

Bulk erasers are on flea bay all the time and they will always be around so you can pick one up whenever get around to it. The little Radio Shack handheld ones work just fine, no need for anything bigger than that.

BTW - you probably know this but the speed on that machine should only be changed when it's in the stop mode, never while it's running.

Glad you got 'er working, enjoy!
 
While a pretty basic deck, the TC377 is an excellent performer and well worth the effort to restore it to 100%.

Cheers!
 
Everything is sounding good!

I had to adjust the motor torque and tension arm, but I followed the service guide and enjoying some pre-recorded albums that I picked up. I don't have the tools to tune it 'perfectly', but it feels close. Also, are newer machines easier to tune up than these older ones? The idea of needing to have the exact load on certain springs, etc is a bit of a pain. Thinking in the future it might be better to pick up a later solid state model.
 
Yes, solenoid operated three motor machines are going to be a step up for sure but what you've got there is a really decent entry level machine capable of very good results when it's all dialed in properly (and actually it's an updated modern version of an older machine, it's not as old as you might think). To get all of the bugs out it's really got to be torn down and properly cleaned/relubed rather than lubricated over old dried up lube but it's a process that you'd have to go through on any machine that hasn't been serviced recently.
 
Oh, yes. I plan on enjoying this unit for quite a bit. Just thinking about the future. I always wanted a R2R machine but found them expensive; I was lucky to find this unit in a thrift shop for only $20. When I have the money, I would, of course, love to upgrade.

In the meantime, it seems to be working great and I'm quite happy!
 
I have just got the same deck and I need to change the belts. Do I need to remove the L and R reel holders for the two belts on the left side (looking at the front)?
 
Michael...
You have done a great job resurrecting that TC-377.
These are one of the nicer single-motor decks.
Good luck.
Graham
 
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