Replacing belts on a Realistic SCT-7

81vee

New member
G'day guys,

I have recently plunged into the world of cassette tape decks with a relic from my great-grandfather: an old Realistic SCT-7 from the mid 70's. Unfortunately, due to age and unuse, it seems that both the drive belt as well as the belt that drives the cassette tape heads (not sure what you would call it) have failed. Completely. I took the rear cover off of it to discover a shriveled up peice of rubber half he length of the replacement belt I have ordered. I want to replace these belts, but I'm not a qualified electrician or any of the sort. Any suggestions for what to remove to access what I need? Thanks!

-81vee

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I don't know the machine at all (American?) but there are some basic principles.

Have a clean, non slip work surface, a white sheet is good.
Take copious photos AS YOU GO.
Make a note of any screws or circlips of different sizes and where they go.
Get the RIGHT TOOL for circlips and screws
Grease is anathema to tape belts, have ISOPROPA on hand to de-grease belts and drive surface.

Dave.
 
Thanks for the advice. It is indeed an American model. Reason why I was asking is because none of the original belts were on the machine when I got it. They were completely gone due to age and use. Therefore, I don't know the pattern of the track of the belts, and some of the screws that hold it together seem permanent, like they are glued, and I don't want to strip anything.
 
Thanks for the advice. It is indeed an American model. Reason why I was asking is because none of the original belts were on the machine when I got it. They were completely gone due to age and use. Therefore, I don't know the pattern of the track of the belts, and some of the screws that hold it together seem permanent, like they are glued, and I don't want to strip anything.

Ah! The Green ***t! The Japanese loved that stuff, it is a weak locking glue. You can pick it off the surfacw and the screw head with a scalpel then, using the DEAD RIGHT driver, apply steady pressure then SNAP! the screw to start it. Often easier with a mate.

The belt pattern should be fairly obvious (not an AMG Merc' twin cam with AC and a blower!) but otherwise you will have to search the infernalnet for a service (not 'user') manual or failing that, a like minded bod with a good one who will send pics. You will probably have to sing up to a few grimy websites!

BTW that LOOKS like a 'capacitor start and run' induction motor (with the fan) maybe look as well for the capacitor for it. Known failure in EU Grundigs of the era.

Dave.
 
Ah! The Green ***t! The Japanese loved that stuff, it is a weak locking glue. You can pick it off the surfacw and the screw head with a scalpel then, using the DEAD RIGHT driver, apply steady pressure then SNAP! the screw to start it. Often easier with a mate.

Update. I've tried and tried to saw as much of that green stuff off, but it's proven to be difficult. No matter how much I get off and how hard I push and turn counter clockwise with a screwdriver, I get nada. I really don't want to strip the heads of the screws any more if I can help it.

The belt pattern should be fairly obvious (not an AMG Merc' twin cam with AC and a blower!) but otherwise you will have to search the infernalnet for a service (not 'user') manual or failing that, a like minded bod with a good one who will send pics. You will probably have to sing up to a few grimy websites!

Yeah, it's going to be tough. Apparently 99% of the Internet hasn't heard of this particular model, so I got barely anything.

BTW that LOOKS like a 'capacitor start and run' induction motor (with the fan) maybe look as well for the capacitor for it. Known failure in EU Grundigs of the era.

Dave.
The fan is working just fine. Maybe a little noisy, but it's okay so far.
 
Alright, got the main belt installed! Took me about two hours of fiddling and running it through its bowels, but it's hooked up. Unfortunately, I'm still unsure what the big fat band is for. Tried running it, but doesn't play when I try. It just auto-reverses like the tape was at the end of its track :facepalm: . I'm gonna have to tinker more or something.

**Update**

Pulled the drive motor, and it looks like it's toast. :(
Played it with it taken out, and the thing didn't even make a noise. It isn't seized either. If you spin the belt by hand, it won't auto-reverse F.Y.I. I gather parts might be hard to find for a mid 70's Realistic cassette player.

Tested the "pause" switch for the motor. Nothing of note.
 
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Is it a multi-motor deck? I assumed that it would be single-motor, and the main drive pulley would be just below the fan.
EDIT: Also, if it is a capacitor-start motor, that could be the problem rather than the motor itself.
 
Is it a multi-motor deck? I assumed that it would be single-motor, and the main drive pulley would be just below the fan.
EDIT: Also, if it is a capacitor-start motor, that could be the problem rather than the motor itself.

I do not believe that this is a multi-motor deck. Attached is a diagram of what I know and don't know. In terms of whether if it is a capacitor-start motor, I am uncertain. My guess would be... maybe? Is there a way to tell? If it helps, there are two leads coming off the motor. One is for the "pause" function, which leads to a switch that opens a circuit, leading to somewhere across the unit. The other runs underneath the main board.


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In grey, I drew the approximate path of the new drive belt I installed.

*Update*
Manually moving the drive belt by hand while the unit is in "Play" mode yields no result. The unit doesn't seem to be reading the tape either.
 
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Are you absolutely sure that there's no drive pulley under the fan? I would wager that that's the drive motor for your 'unknown belt' on the right. Often on tape decks there's a fan attached to the main motor to keep it cool - it really doesn't look like an ordinary fan motor.
 
Mate, you're a genius. All of a sudden, everything works! I guess the "motor" was just a sensor for the auto-reverse. The real one was the "fan". After fiddling with the position of the drive belt, it seems to be okay now. More fiddling will probably be necessary. Thanks a bunch!
 
Mate, you're a genius. All of a sudden, everything works! I guess the "motor" was just a sensor for the auto-reverse. The real one was the "fan". After fiddling with the position of the drive belt, it seems to be okay now. More fiddling will probably be necessary. Thanks a bunch!

Glad that's got it going! I don't know what the small motor thing is either, it might be some kind of 70s rotary encoder or something, but it did look a bit too anaemic to run a deck like this all by itself.
 
Glad that's got it going! I don't know what the small motor thing is either, it might be some kind of 70s rotary encoder or something, but it did look a bit too anaemic to run a deck like this all by itself.

It ends up that the "motor" is just a sensor that lets the tape deck know when the tape has reached the end of its reel and auto-reverses it based on the user-selected setting.
 
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