JVC RC-M71JW Play and FF stops after few seconds.
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Transistorized
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If it rewinds all day long (with a tape loaded) without stopping and only does it on play and FF there are 2 things likely to cause this.
Note: it is normal for it to stop in Rewind without a tape. Auto-stop engages whenever the counter stops due to a stalled take-up spindle.
1: worn/hardened idler tire on the take-up spindle and/or clutch wheel.
Note: I doubt the issue is a hardened or worn out clutch tire because according to your description rewind is fine. The same tire on the clutch is used for Rewind as FF. More likely the take-up tire.
2: Slipping counter belt
To see if it is the idler tire on the take-up spindle, open the door. Press fast forward with no tape. See of it will do that for a minute without stopping. If it does not stop, apply a slight drag on the spinning take-up spindle with your fingers. It should resist you and have a little bit of torque. If you can stop it easily the tire has hardened on the spindle. This should apply true in Play as well. Take up spindle should fight you a little to stop it...not easily stop.
In essence what is happening is the take-up spindle is stalling during tape play which, in turn, is stopping the counter belt from moving the counter wheel causing the auto-stop circuitry to engage. Thats a good thing because this keeps your tape from getting eaten. In a worn take up tire, the closer to the end of the tape you get, the more likely it will stop due to the increased drag from a fully or nearly full take-up spool.
So how do you fix it? Well, you would need to take the box apart, remove the deck. Go ahead and remove belts (they'll need replacement anyway). Inspect idler tire on the FF/Rew clutch wheel. Clean with isopropyl alcohol if not cracked and hardened or replace if it is cracked or hardened. Inspect the tires on both front spindles. Replace any cracked or hardened tires. Sometimes you can clean them and they will work for a while longer but if you've gone through this much trouble you'll likely not want to revisit this issue again anytime soon. I doubt you will find tires anymore but some have found o'rings or know someone on here that is able to make or has found what will work good on this deck.
Finally install new belts (main drive and counter belt). Adjust tape speed and put back together.
It will play like new.
99.9% of all auto-stop issues in these decks are due to slippage as a result from worn out rubber components.
Note: it is normal for it to stop in Rewind without a tape. Auto-stop engages whenever the counter stops due to a stalled take-up spindle.
1: worn/hardened idler tire on the take-up spindle and/or clutch wheel.
Note: I doubt the issue is a hardened or worn out clutch tire because according to your description rewind is fine. The same tire on the clutch is used for Rewind as FF. More likely the take-up tire.
2: Slipping counter belt
To see if it is the idler tire on the take-up spindle, open the door. Press fast forward with no tape. See of it will do that for a minute without stopping. If it does not stop, apply a slight drag on the spinning take-up spindle with your fingers. It should resist you and have a little bit of torque. If you can stop it easily the tire has hardened on the spindle. This should apply true in Play as well. Take up spindle should fight you a little to stop it...not easily stop.
In essence what is happening is the take-up spindle is stalling during tape play which, in turn, is stopping the counter belt from moving the counter wheel causing the auto-stop circuitry to engage. Thats a good thing because this keeps your tape from getting eaten. In a worn take up tire, the closer to the end of the tape you get, the more likely it will stop due to the increased drag from a fully or nearly full take-up spool.
So how do you fix it? Well, you would need to take the box apart, remove the deck. Go ahead and remove belts (they'll need replacement anyway). Inspect idler tire on the FF/Rew clutch wheel. Clean with isopropyl alcohol if not cracked and hardened or replace if it is cracked or hardened. Inspect the tires on both front spindles. Replace any cracked or hardened tires. Sometimes you can clean them and they will work for a while longer but if you've gone through this much trouble you'll likely not want to revisit this issue again anytime soon. I doubt you will find tires anymore but some have found o'rings or know someone on here that is able to make or has found what will work good on this deck.
Finally install new belts (main drive and counter belt). Adjust tape speed and put back together.
It will play like new.
99.9% of all auto-stop issues in these decks are due to slippage as a result from worn out rubber components.
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Many thanks for that level of detail.
Looked at it further. The tape counter wasn’t turning when the unit keeps shutting off. I can reset the counter to zeroes and it gets slightly better, with the counter moving sporadically.
REW is just the same as FF or Play.
Definitely linked to the tape counter.
In Play the spindle can be stalled with my finger really easily. In REW it has a lot of torque. FF also has a lot of torque to stop.
So, seems we have diagnosed the take up spindle tire is worn out? I’m happy taking the unit apart to confirm.
When I find the offending tire I’ll figure out the best way to repair.
Is there a pack of regular belts easily available?
Appreciate your help.
Looked at it further. The tape counter wasn’t turning when the unit keeps shutting off. I can reset the counter to zeroes and it gets slightly better, with the counter moving sporadically.
REW is just the same as FF or Play.
Definitely linked to the tape counter.
In Play the spindle can be stalled with my finger really easily. In REW it has a lot of torque. FF also has a lot of torque to stop.
So, seems we have diagnosed the take up spindle tire is worn out? I’m happy taking the unit apart to confirm.
When I find the offending tire I’ll figure out the best way to repair.
Is there a pack of regular belts easily available?
Appreciate your help.
Transistorized
Member (SA)
Sounding more like belts. Possibly take up tire. The clutch that drives the take up spindle in play mode is different from FF/Rew clutch. It uses the back side of the 9.6 belt driven by the motor. If the FRM9.6 belt is stretched it will lower torque in play and stall easily. Also it sounds like your counter belt is stretched. If FF has plenty of torque then Possibly tire is fine. You won't really know until you take apart.
I wouldn't get belts from eBay. The counter belts don't seem to be as much of an issue but the main drive belts are usually too wide.
You need a FRM9.6 (main drive belt) and SCY7.0 (counter belt).
Main drive belt that will work is this one
A little tech tip for troubleshooting. While in play mode, if you press the pause button just enough to make the green pause light on the front to illuminate, it turns off auto-stop circuitry as long as the green light is lit.
^^^This should only be used for test purposes to see what is actually stopping while playing a tape. The take up spindle and counter or only the counter. If the take up is going when the counter stops, its the SCY7.0 belt....but replace both anyway. They're both worn. If the take up stops along with the counter it's main belt and possibly take up tire. It can also be an excessively slipping play drive clutch (which is adjustable) but that's another topic all in itself. I would focus on belt replacement and looking at spindle tire.
Keep in mind, that if you do this and bypass the auto-stop circuitry in this manner and the take up spindle is what is slipping, you will start to unravel your tape around the capstan. So do this at your own risk with a crappy tape for troubleshooting only.
I wouldn't get belts from eBay. The counter belts don't seem to be as much of an issue but the main drive belts are usually too wide.
You need a FRM9.6 (main drive belt) and SCY7.0 (counter belt).
Main drive belt that will work is this one
A little tech tip for troubleshooting. While in play mode, if you press the pause button just enough to make the green pause light on the front to illuminate, it turns off auto-stop circuitry as long as the green light is lit.
^^^This should only be used for test purposes to see what is actually stopping while playing a tape. The take up spindle and counter or only the counter. If the take up is going when the counter stops, its the SCY7.0 belt....but replace both anyway. They're both worn. If the take up stops along with the counter it's main belt and possibly take up tire. It can also be an excessively slipping play drive clutch (which is adjustable) but that's another topic all in itself. I would focus on belt replacement and looking at spindle tire.
Keep in mind, that if you do this and bypass the auto-stop circuitry in this manner and the take up spindle is what is slipping, you will start to unravel your tape around the capstan. So do this at your own risk with a crappy tape for troubleshooting only.
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The take up pulley and supply pulley tires seem to be in decent shape. They certainly have rubberyness to them, and arnt hard and really cracked. Same with the smaller tire on the slightly yellow wheel. Micro cracks maybe, which does indicate a level of hardness.
The counter belt isnt tight, but I read it shouldn’t be. When I manually turn the spindle the tape counter moves fine through the belt.
I‘ve cotton bud and alcohol swabbed everything. A quick test while the carcass is out is positive. FF and REW and Play like a champ.
I’m tempted to put it all back together and see how I go. Maybe things just got dirty over years.
One question. I unscrewed this spring plate unintentionally. Now can’t find how it goes back. Any diagrams of its location?
Edit: cassette door spring. Sorted that.
The counter belt isnt tight, but I read it shouldn’t be. When I manually turn the spindle the tape counter moves fine through the belt.
I‘ve cotton bud and alcohol swabbed everything. A quick test while the carcass is out is positive. FF and REW and Play like a champ.
I’m tempted to put it all back together and see how I go. Maybe things just got dirty over years.
One question. I unscrewed this spring plate unintentionally. Now can’t find how it goes back. Any diagrams of its location?
Edit: cassette door spring. Sorted that.
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Transistorized
Member (SA)
Glad it's working for now. Cleaning may help for a while. It doesn't take much rubber wear to induce issues.
To get to this point you seem mechanically inclined. My personal recommendation before you put it back together would be, if you feel comfortable with the task, to at least replace the counter belt. It's not supposed to be tight but there is a "just right" tension that when slightly stretched, even just a little, becomes problematic. I've seen them so slightly worn that the machine would run fine until the counter tried to turn all 3 digits (099 to 100, etc.) or a counter reset was performed. Then the belt would slip and engage auto-stop. With the deck in FF you should not be able to stall the belt or counter by lightly feathering your finger over the rotating numbers of the counter. It should have enough torque to overcome the light contact of feeling the counter wheel(s) rotating under your finger. If not, its too loose and will start stopping again periodically in short order.
I'm glad it appears to be working though. You have enough ammo here to get you going in the right direction. Good luck with your project and happy booming
Video of my last repair. Deck and treble potentiometer repair. Excuse the mess. It was after Christmas time and this room gets cluttered with gift wrap, bags, decorative doodads and such by the wife. I remember it adding to the frustration of getting the box working but I prevailed nonetheless. .
To get to this point you seem mechanically inclined. My personal recommendation before you put it back together would be, if you feel comfortable with the task, to at least replace the counter belt. It's not supposed to be tight but there is a "just right" tension that when slightly stretched, even just a little, becomes problematic. I've seen them so slightly worn that the machine would run fine until the counter tried to turn all 3 digits (099 to 100, etc.) or a counter reset was performed. Then the belt would slip and engage auto-stop. With the deck in FF you should not be able to stall the belt or counter by lightly feathering your finger over the rotating numbers of the counter. It should have enough torque to overcome the light contact of feeling the counter wheel(s) rotating under your finger. If not, its too loose and will start stopping again periodically in short order.
I'm glad it appears to be working though. You have enough ammo here to get you going in the right direction. Good luck with your project and happy booming
Video of my last repair. Deck and treble potentiometer repair. Excuse the mess. It was after Christmas time and this room gets cluttered with gift wrap, bags, decorative doodads and such by the wife. I remember it adding to the frustration of getting the box working but I prevailed nonetheless. .
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Thats a very sharp looking box.
What volume were you playing that clip at? My needles tend to barely move at regular listening volumes. They only get some life in them at a noise level that will annoy the neighbors.
It went back together before I thought to order belts. I think I will give it another couple of weeks of daily use and see how it performs.
Thanks for those belt images. I will get those in house now for when it comes to take it apart again.
My box, slightly scuffed, but nothing too serious.
What volume were you playing that clip at? My needles tend to barely move at regular listening volumes. They only get some life in them at a noise level that will annoy the neighbors.
It went back together before I thought to order belts. I think I will give it another couple of weeks of daily use and see how it performs.
Thanks for those belt images. I will get those in house now for when it comes to take it apart again.
My box, slightly scuffed, but nothing too serious.
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Transistorized
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Thank you for the kind words.
I think the volume was roughly 50%. I only used to annoy one neighbor but he is in a permanent care facility now so there is no one close around anymore.
All 3 that I have repaired. The far left is my parts box. It will be the one sacrificed if anything happens to the other two. But all 3 are fully functional with the parts box having one dead meter.
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Very nice trio. Not sure what’s so special about these boxes, but I’m so pleased I’ve got one.
And my needles move just fine around half volume so I’m good.
Appreciate the help. I’ll be back.
And my needles move just fine around half volume so I’m good.
Appreciate the help. I’ll be back.
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