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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

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Old 22nd Jun 2021, 10:36 pm   #21
Uncle Bulgaria
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Default Re: Uher CR 210 Cassette Recorder Check Out

I've just tried putting the borked Record switch back in the one here and found I can get the motor to run. If you want a second opinion show me the contacts you're monitoring and I can see if they match. The motor here is silent and functioning well in FF and RW.
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Old 22nd Jun 2021, 10:46 pm   #22
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Default Re: Uher CR 210 Cassette Recorder Check Out

What happens to the rotating motor when FF & RW are selected, any change of speed/direction ?

David
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Old 22nd Jun 2021, 10:50 pm   #23
Uncle Bulgaria
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Default Re: Uher CR 210 Cassette Recorder Check Out

Yes, speed increases. No, it continues in the same direction. As I haven't yet replaced the belts, the relevant drive spool doesn't move, so it detects tape end and returns to idling speed within a second or two of selecting FF/RW.
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Old 22nd Jun 2021, 10:56 pm   #24
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Default Re: Uher CR 210 Cassette Recorder Check Out

Thank you, as I said in an earlier Post my motor speed does not change when FF & RW is selected, have not tried yet to investigate this, maybe it is a separate issue.

David
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Old 22nd Jun 2021, 11:01 pm   #25
Uncle Bulgaria
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Default Re: Uher CR 210 Cassette Recorder Check Out

Ah indeed. I'd forgotten that. I don't think you said whether you had the service booklet as well as the large diagram(s). On pages 13-14 is quite a lot of description of motor function and what the different transistors do.
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Old 22nd Jun 2021, 11:09 pm   #26
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Default Re: Uher CR 210 Cassette Recorder Check Out

At the time I did not have the Service Booklet but did purchase it (downloaded) a couple of days ago and earlier tonight started reading through it.

David
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Old 22nd Jun 2021, 11:12 pm   #27
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Default Re: Uher CR 210 Cassette Recorder Check Out

Quote:
Originally Posted by Uncle Bulgaria View Post
If you want a second opinion show me the contacts you're monitoring and I can see if they match. The motor here is silent and functioning well in FF and RW.
Still trying to find my CR 240 to do some comparative tests. Now that I have got the motor half out I will continue and see what the contacts are like inside.

David
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Old 23rd Jun 2021, 9:14 am   #28
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Default Re: Uher CR 210 Cassette Recorder Check Out

Uncle Bulgaria, is there any discernable motor speed difference between motor idling and forward/reverse play selected ?

David
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Old 23rd Jun 2021, 11:14 am   #29
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Default Re: Uher CR 210 Cassette Recorder Check Out

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Uncle Bulgaria, is there any discernable motor speed difference between motor idling and forward/reverse play selected ?
David
No. The solenoids on top of the tape mechanism just clack on or off in synchronisation, making the pinch rollers move towards and away from the relevant capstans alternately. The motor, and by extension the brass flywheels below continue rotating at the same speed and direction.

With the tape transport down, in 'Stop' the motor stops. It immediately restarts with the joystick in the neutral position.

In post #21 I meant if you uploaded a snapshot of the relevant board with the position you're monitoring that's causing confusion marked, I could see if I have the same result. Maybe the Uher coordinate number is sufficient if it's a known board contact point.
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Old 23rd Jun 2021, 11:38 am   #30
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Default Re: Uher CR 210 Cassette Recorder Check Out

Thank you Uncle Bulgaria, i thought that was the case, just wanted to be sure so that when I get the current motor issue resolved I know then what to expect operationally.

In the attached photo the 3 motor switch connections are the 3 solder pads near top right hand corner, the first pad is above the right hand securing screw for the board. Left to right they are motor connections 11, 12 & 13, the artwork tracks also connect these points to the right hand side of 3.3k resistors R914, R920 & R924 respectively (to the left of the 3 pads).

When I removed the 2 securing screws for the board as part of motor removal I found under the left hand screw a black insulated spacer (to insulate the underside of the board from motor housing metalwork but there appeared to be no spacer under the right screw, unless it has fallen out somewhere.

Talking about fallen out, when I originally removed the bottom cover one of the tiny securing screws fell inside, still trying to find it, it could have fallen out subsequently but may be stuck inside somewhere, a good shake has not
revealed it.

David
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Old 23rd Jun 2021, 2:49 pm   #31
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Default Re: Uher CR 210 Cassette Recorder Check Out

Found the missing insulated spacer, must have fallen out when RHS screw removed from the Motor Drive board.

While trying to find the missing cover screw found a diode on the main board with one end not connected, on the board layout it looks like D13 but not yet seen it on the schematic.

Motor removal slowly ongoing.

David
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Old 23rd Jun 2021, 5:59 pm   #32
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Default Re: Uher CR 210 Cassette Recorder Check Out

Motor now removed. Rechecked the 3 switches continuity to terminal 4, all still not correct.

Struggling at the moment getting inside the motor as cannot remove the motor pulley or the pulley off the other end of the motor shaft, both feel solid on the shaft. Motor is quite delicate so cannot be too heavy handed, do not want to bend the motor shaft.

David
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Old 23rd Jun 2021, 6:57 pm   #33
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Default Re: Uher CR 210 Cassette Recorder Check Out

Quote:
Originally Posted by DMcMahon View Post
While trying to find the missing cover screw found a diode on the main board with one end not connected, on the board layout it looks like D13 but not yet seen it on the schematic.

The copy schematic I have is what I would call poor but so far as I can make out D13 is connected back to back (anodes) with D12, their cathodes being connect to two switches and the diode outputs from the reverse sensor receiver light detectors, the diode is shown on an imaginary line drawn upwards from F10 in the component location strip at the bottom of the schematic.

Lawrence.

Last edited by ms660; 23rd Jun 2021 at 7:04 pm. Reason: extra info
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Old 23rd Jun 2021, 7:46 pm   #34
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Default Re: Uher CR 210 Cassette Recorder Check Out

Thank you Lawrence, I can now see it.

There appears to be some differences depending upon which schematic is checked.

My original large service sheet/schematic that came with the CR 210 shows the 2 switches (relay contacts rel. b1 and rel. a1) but the schematic in the Service booklet manual that I downloaded does not appear to show these relay contacts (at least not connected to the diode cathodes) what it shows is direct connections from the cathodes, D12 cathode to the bottom end of Rel. B coil (s) D13 cathode to the bottom end of Rel. A coil (s) ?. As shown on schematic section attached.

David
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Old 23rd Jun 2021, 8:04 pm   #35
ms660
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Default Re: Uher CR 210 Cassette Recorder Check Out

Yes it's different for sure.

Lawrence.
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Old 23rd Jun 2021, 8:06 pm   #36
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Default Re: Uher CR 210 Cassette Recorder Check Out

Cannot see any Rel. A or Rel. B contacts on the schematic in the Service manual I must be missing something.

David
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Old 23rd Jun 2021, 8:56 pm   #37
ms660
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Default Re: Uher CR 210 Cassette Recorder Check Out

Quote:
Originally Posted by DMcMahon View Post
Cannot see any Rel. A or Rel. B contacts on the schematic in the Service manual I must be missing something.
Transistor T701 or T703 might perform the same function as the b1 and a1 contacts, that's to say grounding one of the clamp diodes (D801, D802) from the auto reverse detector outputs depending how the flip flop is set (T702 and T704) Is there any circuit description in your manual?

Lawrence.

Last edited by ms660; 23rd Jun 2021 at 9:06 pm. Reason: extra info
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Old 23rd Jun 2021, 10:54 pm   #38
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Default Re: Uher CR 210 Cassette Recorder Check Out

Yes it does, I will extract and attach the relevant pages tomorrow.

Confusingly (for me at least) it references the relay contacts but I cannot see them on the schematic in that manual ?

David
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Old 24th Jun 2021, 8:26 am   #39
DMcMahon
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Default Re: Uher CR 210 Cassette Recorder Check Out

Unable to extract pages, so complete manual is attached.

Page 4 covers mechanical control aspects of relays A and B.

Pages 10-14 covers relevant electronics. Page 11 references relay contact rel.b1 and somewhere rel.a1 is also referenced.

David
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Old 24th Jun 2021, 11:35 am   #40
ms660
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Default Re: Uher CR 210 Cassette Recorder Check Out

Thanks for the link to that schematic, yes, the contacts seem to have disappeared...

Lawrence.
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