Uher CR 210 Cassette Recorder Check Out

[DMcMahon]

After quite a struggle got the motor dis-assembled, the 2 brass pulleys were not keen to come off the motor shaft at all. Needed heat and leverage, think a very tight interférence fit, not looking forward to refitting the pulleys.

Found 2 of the 3 sprung contacts are stiff and feel graunchy when contact moved against its spring, hopefully with a good clean these will improve. The third contact is free to move, but its centrifugal weight fouls (stopping the contact full range of motion against its spring) a brass circular disc that sits on the motor shaft behind the contacts assembly. The disc was tilted over, I have now re-aligned it and the contact now does not foul.

The 3 segment copper contact plate that the 3 contacts make contact with needs a good clean.

David

[Uncle Bulgaria]

Well done David! It does look like in this case that the mechanics are to blame. Perhaps someone dropped it? I seem to remember pressing the pulley back on with a vice, or a hammer and block, and your mention of heat makes me remember (imagine?) playing a blowtorch around it.

There's quite a lot of slop in the motor on the CR 210 I have here, so I don't think the pulley location on the shaft is that critical. When it starts up, the belt pulls the shaft out of the motor housing a little way, presumably to align itself with the forces at play.

[DMcMahon]

I tried soldering iron heat without success, used hot hair drier.

David

[Uncle Bulgaria]

I've got some broken tiny wires on my CR 210 between the solenoid relays and board 600. You wouldn't happen to have a photograph or drawing of the arrangement of these wires, David? The actual switching links don't seem to be marked on the service sheets, but I could be wrong...

[DMcMahon]

I think Posts 34-40 is referencing the relay contacts connections not being shown in the service manual I have (but shown in large service sheet ?).

Tomorrow will try and get some photos.

David

[DMcMahon]

I think I can see at least 2 broken/cut wires in your photo Uncle Bulgaria, a brown wire going to the RHS relay and appearing broken/cut in lower middle of photo and a greeny yellow wire going to LHS relay and appearing broken/cut in the middle of the photo towards the right hand side.

Luckily due to lack of time have not yet progressed my 210 so the assembly in question is out of the machine, so easier to see/photo.

Photo attachment 1 and 2 show the brown wire connecting over to the lower middle contact of the LHS relay.

I cannot see where the greeny/yellow wire on your photo connects to, if you can identify which contact on the LHS relay it connects to, I can check mine again.

In your photo near top left above the right hand green Tantalum capacitor is a component that at first glance looks like a resistor ? On mine (Photo 3) it is a diode (BA181 on schematic and board layout), Photo 4 shows the same diode on the right hand hand side of my board.

Have you noticed any operational faults due to these wires being not connected ?

David

[DMcMahon]

On my photos 1 and 3 there are 2 wires (brown and black) connecting to solder pad to the left of the black connector. On your photo there possibly is only 1 wire so wondering if that could be connection point for your greeny/yellow wire ?

David

[DMcMahon]

Originally Posted by DMcMahon

In your photo near top left above the right hand green Tantalum capacitor is a component that at first glance looks like a resistor ? On mine (Photo 3) it is a diode (BA181 on schematic and board layout), Photo 4 shows the same diode on the right hand hand side of my board.
David

I have just realised that the colour code on your component is brown grey brown so 181 so must be the BA 181 diode.

David

[Uncle Bulgaria]

Thank you very much, David. I missed those earlier posts about the relays - I think the e-mail notification I got was subsequent to them.

Last night I put it all back together (having dismantled it back to the casting according to the manual - very handy to get the soldering iron in) and discovered the broken wires meant the solenoids didn't hold.

Further close inspection of the diagrams showed that they've included the two relays a2 and a3 on the "AF- and Power Supply Circuit Diagrams", over by the tape heads. Tracing those connections back to the Record switch S1 gave me some inkling, but Relay B is not shown anywhere as far as I can see.

Linking the green wire and the loose one from Relay B to the central lower contact on Relay A means the solenoids stay in, but Pause doesn't work. I took one of the golds back to the board 600 where it looked like there was a break.

I'll trace them further with your photos as reference now. Yours certainly has more protection built in, as the mass of wires is enclosed in a tube! Mine are loose, and seem to be mostly the same brownish colour and on some the insulation is peeling off entirely.

[DMcMahon]

Well done on finding the a2 and a3 contacts, I thought that there must be more contacts somewhere.

The Word section of my large schematic/service sheet in Post 34 shows both coils of relay a and both coils of relay b plus the a1 and b1 contacts circuitry/connections.

The Service manual in Post 39 does not appear to show the a1 and b1 contacts, actually is shown wired differently which I do not understand at all ?

I have not had time to look at Pause electrical control.

David

[DMcMahon]

Relay Rel. a & Rel. b contact positions and Magnet Control Electronic board connections.

[Uncle Bulgaria]

Hmm. None of my sheets have that a and b relay drawing, nor are they in the two colour overlay shown in your photographs. My sheets are valid from serial number 164241000, but the unit here is 164201375, so possibly there was a relay change later in production. If your drawings are the earlier ones then they'll be for my model more than the sheets I have!

Can I prevail upon you to compare your relay connections with the ones I've drawn in post #49? Looking at your photographs, like mine some of the wires have faded, and combined with them being bundled into the tube, I can't quite see which ones go to which contact.

[DMcMahon]

My downloaded manual (as per Post 30) Circuit Diagram says from serial number 164241000, so possibly the same as your sheets.

My large Service sheet/circuit diagram with the two colour overlay says from serial number 164201001 so is earlier than the manual version.

My CR 210 serial number is 164206876.

I will compare my relay connections, this will take some time, as you know it is not easy to do properly and will be a real test for my eyesight.

David

[Uncle Bulgaria]

Thank you David, that's very kind. It was a lot easier for me to trace them without the protective sleeve featured on yours - some fine tweezers, and despite the variable colours they were quite easily separated.

I hadn't realised your PDF manual included the sheets - my physical copy has the booklet as one entity, which finishes with the list of component reference numbers. That booklet has no serial number indication, but the two separate folded sheets do and they look exactly the same as your PDF.

Your two colour one must be the "AF- and Power Supply Circuit Diagrams", and would seem to be the definitive edition for both our models.

I still can't find b1 anywhere on the sheets. The relays marked in the board 600 'magnet control electronic' diagram only feature the three wires that connect to the far left and right of the physical board 600. I think as these have resistance values in, and remembering my investigations with the CR 240, they are the coil connections, rather than anything to do with the switched relay connections.

I'll try to trace the a2 and a3 tape head connections in case that sheds light on my solenoid issues. Some of the connections are wrong, as playing in reverse works, but attempting forwards causes the reverse solenoid to oscillate, and pause doesn't work either. Fast forward and rewind don't mute the output (perhaps this is normal behaviour) so are quite noisy in the headphones. This latter could be something to do with faulty decoupling capacitors, I suppose.

[DMcMahon]

Attached drawing section shows the a1 and b1 contacts on the right hand side.

David

[DMcMahon]

In early stage of checking out the relay contact wiring.

Where you indicate BLACK 2/GOLD 2/GREEN 2 are these single wires you are identifying as # 2 or 2 wires of that colour ? I am asking this because for example on your drawing on the top left of Relay A you indicate "GREEN 2" but on mine there are 2 green wires there.

Other observations so far:-

Top right 4 pin socket connector (grey on mine) you identify the right hand pin as 614, on the drawing it is 612.

On the black 4 pin socket connector you identify the right hand pin as 608, whereas on the drawing 608 is the left hand pin with the right hand pin being 605.

David

[Uncle Bulgaria]

Thank you, David. I think your coloured sheet is the one to use. Those board 600 connection socket numbers are from the 164241000 sheet I have, which doesn't show relay b1 in the location your post #55 does, and has a different board 700 layout with other components than what I have in the unit, too. I bet there are more differences if you compare the green sheet to the one in your PDF earlier.

However, be aware that the pin layout of the black/red/grey sockets does not correspond with the four contacts laid out next to them. The leftmost contact on the black socket is connected to the rightmost of the neighbouring four pcb connections, for example.

The numbering I've used is for #2: green goes to green, and green 2 goes to green 2. If there are two wires I've shown them both coming from the same connection.

[DMcMahon]

Sorry it is in dribs and drabs, finding it quite hard and trying not to beak my wires off.

Your green wire at bottom contact of relay A A1 should connect to the middle contact (A1) of relay B, this is shown on my photos 1 and 2 of Post 46 (looks like a brown wire in the photo but is actually violet). There is another wire connected to this bottom contact of Relay A (black in my case), this connects back to 602 via the third solder pad to the left of the Red 4 way connector. On your drawing you identify this as "Black to tape heads ? " This is the ground connection at 602 shown going to A1 as shown in Post 55 attachment.

David

[DMcMahon]

Originally Posted by Uncle Bulgaria

Thank you, David. I think your coloured sheet is the one to use. Those board 600 connection socket numbers are from the 164241000 sheet I have, which doesn't show relay b1 in the location your post #55 does, and has a different board 700 layout with other components than what I have in the unit, too. I bet there are more differences if you compare the green sheet to the one in your PDF earlier.

Quite possibly.

However, be aware that the pin layout of the black/red/grey sockets does not correspond with the four contacts laid out next to them. The leftmost contact on the black socket is connected to the rightmost of the neighbouring four pcb connections, for example.

Yes noticed that.

The numbering I've used is for #2: green goes to green, and green 2 goes to green 2. If there are two wires I've shown them both coming from the same connection.

OK clear, you only show 1 green wire, whereas I have 2 green wires in the example quoted.

David

[DMcMahon]

When you say "twined with" what that does that mean ? e.g. yellow to tape heads twined with black 3.

David