Take up spool not turning

[Matty]

Anyone have any knowledge regarding the tape mechanism on the Hitachi 8180? Think it’s the same mech as the 8080?

Replaced the three belts with brand new correct belts, re-assembled and tried a tape. It will play but the tape soon starts to bunch because the take up isn’t turning. RWD & FFWD work ok, capstan and pinch roller working ok. Took it apart again to check for anything obvious but I cannot figure what is wrong and not allowing the take up to turn when playing. Can’t figure out exactly what is meant to drive the take up spool? Any ideas?

The keys/buttons were quite stiff, due to years of non use and old grease, but managed to free them so they all now operate, but the two DRPS buttons don’t press in, could this be connected to the above take up issue?

 

[BoomboxLover48]

I had the same problem with TRK 8080H. I heard from a few experts here that it has to do with the belt tension.
I also struggled to figure out how the take up reel gets engaged.
I tried adjusting the tension with different size belts and had no success.

 

[Matty]

It’s a tricky one. I’m thinking it may be an idler tyre issue? The one you can see appears ok but maybe it isn’t good enough. Guess I shall have to strip it down some more to really try and work out how it should work and what is possibly causing it to not work correctly. Annoyingly no rubber O rings will fit good enough to act as a temporary fix.

50 is the take up arm assembly according to the service manual, so guess I should investigate that to work out what’s what.

 

[BoomboxLover48]

I spend lots of time to figure out how the whole thing works.

Finally, bought a spare deck assembly for this need.
Installed belts on it and that also had the same issue.

I've worked on so many cassette decks and decks on boomboxes in my collection and this one was very challenging.
It tested my patience a lot!

Feeback on one channel - 8080

After a what I thought was a successful restoration of a poorly 8080 it functioned perfectly for a few hours of tape playback and then threw a wobbly I cannot diagnose. When you press play, you get extremely loud feedback from the left channel (the VU needle kicks wildly over to show this), the...

www.boomboxery.com

 

[Matty]

I know what you mean.

I took it apart again and dug into it, especially that take up arm. You can see a bronze roller on the underside which makes contact with a rubber tyre under the plastic cog. When they touch, it then turns the take up spindle. I made sure they could make contact, which they do, when pressing them together but not when play is selected. In frustration I spun the take up spindle from the tape side whilst the unit was powered and play selected. I noticed that the take up then started to slowly start turning. Some more persuasion and it then began to turn as it should. So put a tape in a left it playing for 30 mins and all was working ok. So not entirely sure what fixed it, whether it was just a bit stuck, which is annoying because it would have been good to give a definitive answer for anyone else.

I did clean the rubber tyre on the take up with some IPA, but that’s about it. Attached a picture of the belt routing, just for future reference if anyone ever needs to know and also a picture of the take up arm and the point it contacts with the rubber tyre to drive the take up.

 

[Matty]

I spend lots of time to figure out how the whole thing works.

Finally, bought a spare deck assembly for this need.
Installed belts on it and that also had the same issue.

I've worked on so many cassette decks and decks on boomboxes in my collection and this one was very challenging.
It tested my patience a lot!

Feeback on one channel - 8080

After a what I thought was a successful restoration of a poorly 8080 it functioned perfectly for a few hours of tape playback and then threw a wobbly I cannot diagnose. When you press play, you get extremely loud feedback from the left channel (the VU needle kicks wildly over to show this), the...

www.boomboxery.com

Ha yes regarding his comment about the take up tyre in that thread, it does look tricky to replace. I did start to dismantle the whole mech but thought better of it as it was late and knew that springs would probably go flying Old enough now to know not to jump straight into dismantling things without fully understanding how they work, and then very slowly dismantle

I do think that the 2 square belts do have to be pretty bang on size wise for the whole thing to work properly. I actually switched out the new one driving against the take up and to the flywheel, for one slightly smaller length wise, which seemed better suited.

Auto stop doesn’t work on mine though, so not sure why, or the DRPS buttons.

 

[BoomboxLover48]

I was having some peace on this Saturday morning and now I will be so tempted to try what you did.

 

[Matty]

You know you want to

It may be that the rubber tyre just gets a bit stiffer after so many years, I don’t know. It certainly wasn’t worn as I don’t think the tape was really used much by the looks of things by the previous owner. Probably won’t work again next time I put a tape in it.

 

[BoomboxLover48]

Yes!
One of these days I will get my hands on it and see how it goes.
It's always a pain to work on these types of decks.

 

[Matty]

Shall strip it apart again as I need to work out why the auto stop and DPRS isn’t working. I think they are related.
The two DPRS buttons don’t engage, like something is stopping them from being depressed, like a lock plate. Don't really want to have to disassemble the whole tape mech though what with the amount of springs, but I may have to.

 

[Matty]

DRPS now works. Stripped the DPRS rwd/ffwd button section completely and found two of the sliding plates were completely stuck together by old grease. Cleaned and re-greased and they now work like new.

Need to fine tune the playback as it’s not quite as clear sounding as it could be, hopefully a tweak of the azimuth screw should help that. Speed is pretty good though at a smidge over the 3khz point. No noticeable speed adjustment on the motor, so I’m guessing it’s hidden away in the motor? But to be honest it’s pretty good as it is speed wise.