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Problem with tape speed (no, its not the motor!)

beatbox - 2007-11-28 10:43

One of my J1's is having problems. Both the tapes play stupidly fast. I mean stupidly, as if high speed dubbing is on.

When I press high speed dubbing, it goes even faster. FF and RW are alos a hell of a lot faster. I have tried tape motors from my other J1, and its the same story. I have switched out the circuit board that connects to the tapes and same story.

So, my theory is that there is simply too much power getting through.

But I do not know this for sure and is really just a shot in the dark.

Please, somebody advise me on what this is and also how to go about fixing it.

I will be eternally grateful!

geoffhartwell - 2007-11-28 10:55

i had same prob when i was puttig new belts on my vz 2500(just playing way to fast only). turned out i had put the belts on wrong, dont know if this will be any help

beatbox - 2007-11-28 11:34

Thanks, but its much worse than that.

Frown

kittmaster - 2007-11-28 11:35

on the sharps, I've seen a transistor control the main power line to maintain 12 or 9 volts, I'm guessing that may be the case here also. Trace the positive lead to motor to the board to see where it lands. If its a 3 pin device, most likely that transistor is bad.

beatbox - 2007-11-28 12:08

Interesting. Thanks, I'll check it out!

beatbox - 2008-01-05 10:41

quote:
Originally posted by kittmaster:
on the sharps, I've seen a transistor control the main power line to maintain 12 or 9 volts, I'm guessing that may be the case here also. Trace the positive lead to motor to the board to see where it lands. If its a 3 pin device, most likely that transistor is bad.


Is there any chance you could possibly let me know what this may look like, just to help me locate it on the board? Thank you again for your help and time!

roddyradiohier - 2008-01-06 04:59

Hey Beatbox,

the J1 uses a 4 pin external regulation motor.The pins on the motor should read (A,B,+,-). What have you measured at the +,- terminals?

I can send you a photo of the motor regulator tomorrow, when I'm back at the workshop , if you can wait that long.

Cheers. Roddy

beatbox - 2008-01-06 07:30

Hey thanks!!!!!

That would be awesome if you could help.

Happy New Year to you too!

- 2008-01-28 18:09

Whell i must state that I HATE BELT PROBLEMS but when it comes to playing to fast it may mean that the belt is to loose or to tight iv never ownd that model b4 but all belts work relativly the same.had this problem with my PC-200 when it was involved in an automotive acsedent had to find a tigheter belt. good luck.

roddyradiohier - 2008-01-29 23:46

It's not the belts, I think there's an open circuit in the speed control feedback circuit. Hows it coming along beatbox, don't hear from you much..

Roddy

beatbox - 2008-01-30 12:29

Hey Roddy, well I haven't got very far at all. I don't really know where to start with trying to fix this and I have no equipment to measure any current or anything like that.

roddyradiohier - 2008-02-01 01:25

Man.. give me a call..!!!! I can call you back if your strapped for cash. Gotta get that beast up and going..

teamstress - 2008-02-02 11:58

I have a J-1 with a similar problem too. Deck "a" plays way too fast in normal mode, but in high-speed dub mode it slows down! Deck "b" played alright until I changed the belts, now it plays fast. arrgh!

roddyradiohier - 2008-02-03 07:18

Hey teamstress,

you have a fault in the motor speed control feedback circuit. The high switch is either faultly or has an open cicuit somewhere. When the motor feedback goes. ie. no feedback , open loop then the motor runs as fast as possible.

How fast does it run in high speed mode?? still faster that it would at normal speed?

Roddy

teamstress - 2008-02-09 10:01

Neither tape deck works now.

roddyradiohier - 2008-02-12 12:48

what did you do then. What do you mean they don't work?

- 2008-02-15 21:24

if the speed wasent right the 1st time and now its not moveing at all the motor is still doing something the only situation i can relate to is when i was oiling my cougar i got a little in the motor i thoght nothing of it untill it wouldent play some tapes or it played slower then normal it was minor at 1st and then it just quit one day. as far as i can see the only ansure i can think off if useing compressed air and trying to dry the motor if it has an opening most do that iv seen. hope something works.