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Pioneer RT 909 Capstan Motor Help??

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Does anyone know how to see if the capstan motor is working properly on my RT 909 unit? It part number RXM 062 with the gold pulley on the end to drive the flywheels. I replaced a lot of things on my dect and it still won't play. I fear the capstan motor may be burnt out but want to check it out first before trying to find a replacement of it. I know that search will be difficult to find as well.

Thanks for any assistance with this.
 
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Make sure the microswitches on the both tensioners are working too as they provide power to the capstan motor.
 
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link said:
Hi Mark. I recently replaced the belt, ball bearings and pinch rollers after sitting in the box for over 12 years. It played for about 5 minutes and then the tape stopped. I removed the capstan motor and took off the belt to see if the the gold pulley would continue to turn...it does but, when I hit play it stops. Can you help me with what the problem may be or guide me to a post or thread. I am the original owner and can't figure it out.

Thanks
Link
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I have seen this thread, and saw that both inductor and pustelniakr are responding. You couldn't be in better hands, IIAC inductor makes his living doing repairs in this arena (for a long time - he has plenty of experience, and I think it is HIS shop) and pustelniakr RESTORES equipment like that to a degree almost certainly unmatched on this planet, so if he is seconding checking the microswitches, do it and tell us about it.... I personally haven't laid hands on a Pioneer reel to reel deck ever - when I was doing dealer service, these babies NEVER came in - although I HAVE worked on high speed duplicators, but those are a different animal altogether.

I'm sure if you asked nice Rabbi Rich (pustelniakr) will tell you the source and parts numbers of some replacement microswitches. There is a pustelniakr thread on here of a pioneer reel to reel tape deck rebuild, but my memory fails me as to whether it is a 909 ot 707. I think it is in turntables and tape, although a search of the threads he has started will find it.

BY THE WAY, are you SURE that you have a tape on it, and that the tape is threaded properly?
 
Here ya go:
http://audiokarma.org/forums/showthread.php?t=93227

Don't be overwhelmed by the initial posts. Scroll down to the posts about rebuilding the tension roller assys. There is where you will find out how to access the switches in question. Whether or not they are the source of the problem, you will want to replace them. These switches have no wiping action to keep the contact surfaces clean and most, if not all, RT-909s have dirty contacts in there. The new ones I use have gold contacts, so this will not occur again.

I promise you, unless this unit has already had restoration ops performed, that the tension roller assys need the spec'd work. You won't be wasting your time. You do want a deck that does what it is supposed to do, right? Instead of just limping by...

Enjoy,
Rich P
 
Hi, I'm new here but have read a lot on this site previously, now time for help.

I recently replaced pinch wheels and belt hoping to get some drive out of capstan but no luck. When I press either direction of play button everything engages, pinch wheels, locks on wheel motor, play light comes on etc. Still capstan does not revolve. With these symptoms, could it still be these microswitches mentioned previously in this post?

Tim.
 
The microswitches in the tension rollers would keep the unit from going into 'PLAY' mode, or drop out of that mode intermittently.

If you put the unit in 'PLAY' with 'PAUSE' active, the pinch rollers should drop away from the capstans slightly, so the tape will stop. The capstans should continue turning. You should then be able to resist the turning of the capstans and feel that they have good torque. If not, the capstan belt, capstan motor, or capstan motor drive (incl. associated control logic) is bad.

Enjoy,
Rich P
 
So not the microswitches then because the play button light up and everything engages.

To note, I don't think it will go into pause mode.
like I say the capstan motor doesn't turn although I changed the capstan belt. How is best to check the motor and motor drive itself?
 
Load up the tape properly. Put it in play/pause. If it does not engage play/pause, you have a starting point. Fix that and go on to the next definitive symptom. Maybe your pause switch is drty or bad, maybe other control swtches are also needing some attention.

First thing...make sure you are threading the machine correctly.

If it does not go into pause, find out why. It is lilkely related to whatever else you are seeing...

Enjoy,
Rich P
 
OK, looking at the four important transistors on Control B board they look pretty burnt on the base, agreed?

76983_10150313322715455_855645454_15751587_5928373_n.jpg


Anyone know a replacement transistor for the b682 ? as this is the number printed on the four transistors that sit next to each other
 
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Darkening of the circuit board is normal, where the components are hot. If the solder connections get hot enough to melt, there you have a problem to fix, with regard to the ciruit board.

Any replacement transistor will also get hot. The only reason to replace any transistors will be if they are bad, not because of darkening of the circuit board. With respect to the driving H-bridge, replace one of the 4 transistors, because it is bad, you should replace all 4. This is because taking one out, will likely stress its mate. You also want to keep them matched in specs and performance. Note that, on occasion, it is the capstan motor, itself, that takes out its drivers. I to could have a shorted winding, or simply need cleaning and lubrication.

There is a thread buried around here, showing how to test a transistor with a multimeter. However, there are more operational tests that can be performed, to narrow down the failure to a circuit, before component level checks and replacements are worth doing.

Enjoy,
Rich P
 
Hello there.
OK so I have got you some pics for the top of the board.
The one closest to us on the left (in first pic) looks to me like it's definately shot, but you no better than I do for sure.

149271_10150314186210455_855645454_15766010_5433533_n.jpg


155611_10150314186300455_855645454_15766012_6158646_n.jpg


148401_10150314186380455_855645454_15766013_1019793_n.jpg


When I replaced the belt the old one had literally melted round the capstan and I think.this put major stress on the motor, its now cleaned and well lubricated, but it still don't know if the motor itself even works

....also, what do you think of a KSA614 as replacement transistors?
I really appreciate your help.

P.s sorry about the other thread markthefixer, I thought that's what you were after, let's keep it to this one?
I'd delete the other if I could...
 
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Well, since you dug up my old thread as well, i'll let you know that i used the TIP 42Cs and have had no problem.

You can test your capstan motor with a 9V battery. Just connect the battery to the motor's power wires. It should spin freely if nothing is wrong. It may turn in a sort of lumpy or labored fashion if it is damaged. It won't turn at all if dead.
 
Numistrek09 said:
Well, since you dug up my old thread as well, i'll let you know that i used the TIP 42Cs and have had no problem.

You can test your capstan motor with a 9V battery. Just connect the battery to the motor's power wires. It should spin freely if nothing is wrong. It may turn in a sort of lumpy or labored fashion if it is damaged. It won't turn at all if dead.
Click to expand...

Are you using UK/Euro power supply? My concern is I need transistors that depend on the power source I.e 240v?

Also, when testing the motor, is it the grey wire that holds the dc connections? The brown wires are pulse?
 
Once your past the voltage selector on the back and the transformer, all voltages in the machine are the same whatever your voltage selector is on so if u get a transisor with the same spec it will all be fine.

Yes, the grey shielded wire on the motor is the power for the motor. The two brown ones are the frequency generator on the motor so dont put any current through the brown ones!

Hope you find that your motor isn't burnt out as new ones are hard to find!
 
QSilver said:
Once your past the voltage selector on the back and the transformer, all voltages in the machine are the same whatever your voltage selector is on so if u get a transisor with the same spec it will all be fine.

Yes, the grey shielded wire on the motor is the power for the motor. The two brown ones are the frequency generator on the motor so dont put any current through the brown ones!

Hope you find that your motor isn't burnt out as new ones are hard to find!
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Eeek, I'm confused...so basically it doesn't matter what the voltage selector is at the circuit boards will be treated as if it was the same power supply because of a transformer.

So basically if the TIP 42Cs are good for Numistrek09 they should be good for me?
 
Well, the mje's seem to handle that heat (no heat sinks on the transistors) better over the long term which is why I suggested it. ONSEMI makes tip42c's as well. Something about OnSemi's manufacturing process?

The darkening of the board suggests finding a better approach to shedding heat, but insulate any heat sinks, so an inadvertent touch (preventing a short circuit) isn't a disaster.
 
photosynth said:
Eeek, I'm confused...so basically it doesn't matter what the voltage selector is at the circuit boards will be treated as if it was the same power supply because of a transformer.

So basically if the TIP 42Cs are good for Numistrek09 they should be good for me?
Click to expand...

Yeah, you can use the 42c's even in Europe. The circuit boards all run on the same voltages no matter what country you are in. But if you are worried about heat, try the MJEs Mark suggests. You can't go wrong either way really.

There's very little room in there to add heat sinks unfortunately. I think there is only about 1/4 to 1/2 inch of space between the transistors and the back of the reel motor.
 
Great, thanks for all your help guys - I'll install some new transistors regardless, probably the mje's if I can get my hands on them.

However I will test the motor first with a 9v battery. My concern is that old belt that will have melted and wrapped itself around the pulley and caused unecessary stress on something, don't know if the stress would have gone mostly to the motor or the transistors?

Either way im away from the unit for a while at a family emergency. With any posts I make to any forums as usual I will keep you updated once I get back on it...step by step, so in the end hopefully we find a solution and it can help others in the future.

In the mean time anyone know a reliable place to buy a new motor?
Though I understand how rare they are...
I believe the Teac EM-1446 is the same as the RXM-062 - can anyone confirm or deny this?
 
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