Pinch roller causing tape to slip on capstan?

analogkid

I Bleed Analog!
My trusty (and very high mileage) Pioneer RT-707 has begun to act up badly, and while I am fortunate enough to have a spare, I would like to have this unit working as well. The symptoms are slow playback in the forward direction (the unit is 1/4" 1/4 track with auto-reverse) and most annoyingly the tape slips on the capstan when you first thread the tape, and specifically slips toward the face of the unit on the leader tape and twists up. The pinch roller has some wear, but swapping it to the spare deck none of the same problems occur. COuld this be a pinch roller tension issue? I do have the service manual available.


AK
 
Is the rubber on the pinch roller hard? I've had a couple of rollers go bad on me and it would throw the tape off the front of the deck, instead of the back like yours. I know you have probably already done this but have you cleaned the capstan and tape path?

I've only got a couple of RT-909 decks, so I'm not really familiar with the 707. Has yours always been like that or has it started recently?
 
Just started recently, as in last night. My second deck I got from Dad (which has WAY less mileage) doesn't do this... the roller is still soft not yet mushy. I did re-clean the tape path and heads, no dice. I am going to send the roller to terry Witt next week and let him fix that up... maybe that is all that is wrong. Has anyone tried this etching chemical to fix overly polished aka worn capstans? I am wondering if that isn't part of the problem.


AK
 
Just started recently, as in last night. My second deck I got from Dad (which has WAY less mileage) doesn't do this... the roller is still soft not yet mushy. I did re-clean the tape path and heads, no dice. I am going to send the roller to terry Witt next week and let him fix that up... maybe that is all that is wrong. Has anyone tried this etching chemical to fix overly polished aka worn capstans? I am wondering if that isn't part of the problem.


AK

I just had Terry rework a roller for me on my GX-230D (Akai) and he does AWESOME work.;) At least I have one deck up and running.

I can't imagine a deck (a consumer level one anyway) getting that much use to wear the guides that bad. Something that just occurred to me: can you reverse the rollers on the shafts? In other words, can you flip the roller over and see if it still does the same thing or if the tape slips off the front? If I remember correctly, the rollers on the 909 are symetrical so I can do that trick. Worth a shot.;)
 
The left side roller on the 707 is hard plastic so the answer is no. You have to understand that this deck his had somewhere very near 800 hours of use - I know that seems crazy but I have owned it since 1981 or so, and it was in daily use for 10 to 12 years. I'm thinking it is the pinch roller and the pinch roller tension... I will tear into the unit tomorrow and see if I can adjust the pinch roller tension - looking at the manual it isn't complciated but getting to it may be a real pain.


AK
 
Ok I have discovered that the take-up side tension arm has very little 'spring' left, and I believe this is teh actual source of the problem. I'll be taking it all apart today to see if I can fab a replacement - no replacement parts are available for the 707s any longer.





AK
 
Ok I have discovered that the take-up side tension arm has very little 'spring' left, and I believe this is teh actual source of the problem. I'll be taking it all apart today to see if I can fab a replacement - no replacement parts are available for the 707s any longer.





AK

Yeow. It's the little things that get you. I'm glad I have a spare unit for parts in case I do have to replace something. BTW, there is a 701 for sale not too terribly far from here. I know it's not an auto-reverse, but figured I would mention it anyway.
 
What are they asking for the 701? Likely I can't spend any more money at the moment, but guess it all depends on price.



AK
 
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