Uher CR 210 Cassette Recorder Check Out
 

Just quickly looking at this CR 210 which is a smaller and simpler sibling to my CR 240.

Sold as not working, with status that powers up but no drive and on/off push button stuck in/down. No AC/DC adapter/charger but did come with a Uher Z 215 NiCad rechargeable battery (fully flat). Came with a somewhat tatty leather case and a bunch of cables plus useful User manual and the very useful large service/schematic sheet.

Found that the stuck down push button is the on/off switch for the internal loudspeaker, have managed to get this moving a little.

Using my Z 131 power adapter from my CR 240 (the 210 uses the same adapter) got it to power up, although somewhat intermittently. Like the CR 240 the cassette tape has to be fitted and lowered down for the unit to power up.

The motor tries to rotate and the main drive belt does move but no sign of the cassette tape moving. Motor speed/direction does not change with FFD, RWD, FWD or Reverse selected. Very difficult to tell properly without a strip down but the 4 belts look intact.

Presently charging the Z 215 battery to see if it will take and hold a good charge.

Will need to do a strip down to check out the belts properly which I am not looking forward to, everything is crammed in so tightly and very delicate.

Re: Uher CR 210 Cassette Recorder Check Out
 

I've got a CR 210 in bits here so can provide cross-checking on the internals if necessary. The battery's intriguing - I've never seen one and have wondered if one could be re-engineered or re-stuffed with new cells. It would be a little more convenient than a load of C cells, as mine has when it's on walkabout..

Re: Uher CR 210 Cassette Recorder Check Out
 

The Z 215 battery appears to have charged OK. Off load it currently measures 8.3V, in the machine the VU/battery strength meter indicates half way (7V), with only the Z 131 (24V) adapter plugged in the meter indicates full scale (> 8V).

Will see how the battery lasts out.

David

Re: Uher CR 210 Cassette Recorder Check Out
 

Removed the cassette carriage assembly. Now can see that the belts from the 2 flywheels to the 2 spool clutches are quite slack, also the main drive belt from motor pulley to the flywheels, so will get a set of new belts.

With main belt slipped off the motor pulley can see that motor pulley basically just oscillates (sometimes is just stationary) when unit is powered up and by touching the motor drive board can sometimes get the motor to spin at high speed. Looks like some sort of bad connection on the board maybe.

Cannot remember from my previous CR 240 work if the motor normally rotates/spins when unit is powered up (with no tape transport demand), if I could only find my 240 then I could check it out.

Since removing the cassette carriage, now have some control of the play and reverse pinch roller arms moving to the respective capstan shafts when Play or Reverse is selected. This control is intermittent and once again looks like bad connection/contact somewhere.

David

Re: Uher CR 210 Cassette Recorder Check Out
 

The charged Z 215 Ni-Cd battery did not last long, now fairly flat after very minimal usage, will try charging again.

David

Re: Uher CR 210 Cassette Recorder Check Out
 

The motor and tape mechanism is basically the same as the CR 240, if not exactly the same. The motor won't start until a tape is inserted, and with the mechanism out you can deceive it by pressing switch K3. Here're the relevant bits from the CR 210 manual. I have the originals, so if you're bereft I could try to scan them.

Re: Uher CR 210 Cassette Recorder Check Out
 

I have the original large schematic thankyou Uncle Bulgaria.

Yes with cassette carriage out I am deceiving it by pressing K3, K3 has to be actuated to get power on. What I was not so sure about is should the motor start as soon as K3 is pressed or only when Play/Reverse/FFD/RWD is selected after pressing K3.

David

Re: Uher CR 210 Cassette Recorder Check Out
 

I should have said that the large schematic has similar servicing info as per your Service manual sheets but not as detailed.

Did you get the manual from SDS or found it online ?

David

Re: Uher CR 210 Cassette Recorder Check Out
 

Marvellous! These Uher drawings are brilliant. Mine came with a 16 page booklet and two large fold-out sheets for the PCBs. If you're missing anything I'm sure I'll be able to send over the relevant information.

The motor will only start when the machine's on, and a cassette has been inserted and lowered such that K3 is actuated. The motor will start as soon as K3 is closed, and will continue to run as long as the cassette is loaded, presumably so it's ready as soon as any of the controls are operated.

Edit: I think they're from SDS when I got the belts. I put the belt sizes in that other recent thread about a CR 240 as they're shared with the 210. The booklet's entitled "Uher Service CR 210 Stereo" and the two sheets are "AF- and Power Supply Circuit Diagrams" and "Drive assembly control electronic and Motor electronic".

Re: Uher CR 210 Cassette Recorder Check Out
 

Many thanks Uncle Bulgaria for the confirmation, that is what I thought and what I think I remembered from the 240 work but because the motor often will not work, sometimes just slowly oscillating and sometimes can be induced to spin by touching the motor drive board I did wonder if my 240 memories were correct.

David

Re: Uher CR 210 Cassette Recorder Check Out
 

It's probably one of those tiny solid wires they like to use, which fracture and cause intermittent contacts. If the motor's the same as the CR 240, it is possible to take it apart and clean it up. It's a faff though so I wouldn't recommend it unless you've ruled out any intermittent connections on the boards. Maybe it just needs a few runs to polish off any corrosion on the contacts. I did replace the isolation foam on the motor casing on my CR 240 as it was crumbling to dust that was likely to cover the tape mechanism...

Re: Uher CR 210 Cassette Recorder Check Out
 

Thank you for the motor information, I hope I don't have to take it apart although it would be interesting to see inside it :)

I think the motor foam looks OK.

David

Re: Uher CR 210 Cassette Recorder Check Out
 

Removed the Flywheels assembly for drive belt replacement, all 4 belts are stretched and will require replacement. They are square section so probably are the original belts, have ordered a set of round belts.

No progress yet on the motor drive issue, seems to have got worse, before could sometimes get it spinning by touching the Motor Drive board, now much more difficult to get it to spin, mainly just slowly oscillates sometimes.

Need to try and monitor the motor signals to see what is happening. Even though I have the large Schematic/Service Sheet, I find it difficult to read/follow the connections, will scan the relevant sections and print out A3 size.

David

Re: Uher CR 210 Cassette Recorder Check Out
 

There is a small wired lamp (grain of wheat type) on the Automatic reverse impulse transmitter board, struggling to see this lamp on the schematic. The lamp is not lit.

David

Re: Uher CR 210 Cassette Recorder Check Out
 

Have now worked out what the lamp is.

On the schematic there is an 8V 40mA lamp shown within a green sectioned area, there are also in/out connections to this green area from K3, K4 and another contact. The green areas are normally PCBs/section of PCBs but this particular section is not identified.

One side of the lamp connects to ground and the other side connects out to contact K2. With contact K2 made/closed the +9.7V supply will be switched through to the lamp.

The giveaway clue to the identified sectioned PCB is that its external connections are numbered in the 900's and the external connections shown on the Automatic reverse impulse transmitter PCB are also numbered in the 900's, so the unidentified green section is part of that PCB.

The schematic lists K2 location as "at the volume control" and User manual says that when the Volume control is pressed in, it will illuminate the cassette inspection window (the PCB is situated below this), now of course remember this lamp from the CR 240.

Pressing the volume control does illuminate the lamp.

David

Re: Uher CR 210 Cassette Recorder Check Out
 

The giveaway clue to the un-identified sectioned PCB is that its external connections are numbered in the 900's and the external connections shown on the Automatic reverse impulse transmitter PCB are also numbered in the 900's, so the unidentified green section is part of that PCB.

Re: Uher CR 210 Cassette Recorder Check Out
 

;)Been checking out the motor connections, all 3 motor windings measure around 13 Ohms measured at the Motor Drive board via the commoned end of the motor windings that connect to the +9.7V supply, so look good.

Not able to get good readings across the 3 motor distributer contacts, on the schematic and in description 2 of the contacts should be grounded and as the motor rotates the grounded pair should cycle around the 3 contacts. Not able to measure any of the contacts being properly grounded, mainly hundreds of Ohms but nothing consistent at all. Measured the ground connection is getting to the motor at terminal 4. So looks like there may be a problem with these contacts but somewhat loath to go inside the motor to check as looks so difficult but may have no option.

Struggling at the moment to measure the +9.7V supply at the Motor Drive board, there must be voltage there because the motor does rotate sometimes, think just bad meter connections, everything is so awkward to get onto, made more difficult by having to press down K3 to get power on.

Uncle Bulgaria - How does the motor drive pulley come off the motor shaft ? and how do the black end caps come off the motor. From your motor photos I assume the 3 contacts are the sprung loaded pins that make contact with the 3 copper segments in the end cap. I think I am going to have to bite the bullet and remove the motor for disassembly to inspect the contacts but first will check the motor drive signals and contacts voltage wise when the motor runs

David

Re: Uher CR 210 Cassette Recorder Check Out
 

Measured the +9.7V supply at the Motor Drive board as around 8.1V, so somewhat low but do not think this has any connection to the motor control problem but will have to check it out later.

Scoped the 3 motor drive signals, all 3 very similar a square pulsed (10mS) with repetition rate of around 40mS so around 25Hz, between 0V and +8V, even though not pretty, as all 3 are doing basically the same I think the main drive electronics is probably OK.

Scoped the 3 motor distributer switch lines, all very similar, a rough waveform with squarish +ve peak and spikey/sawtooth -ve peak (with noise spikes at times), switching between around +2V and -2V. Continuity/resistance checks of these 3 connections to ground as before gives very inconsistent highish resistance connections to ground.

In early stage of removing the motor which as expected is very difficult, hopefully I can get inside the motor and checkout the 3 switched contacts.

Update - forgot to say that becoming increasing difficult to get the motor to spin/rotate, sometimes by manually spinning the motor pulley gets it going for a while. The waveform info above is when the motor is spinning.

David

Re: Uher CR 210 Cassette Recorder Check Out
 

The motor pulley pulls off the shaft. I don't remember it being too difficult. Have you tried leaving it running in case that cleans off the internal contacts? Perhaps the 'Uher rattle' as it gets up to speed will help as well.

Have you traced the ground connections?

I remember the CR 240 boards having some easier positions to access the contacts - instead of the tiny pins on the connecting plugs, for example, some go to more widely-spaced plated holes on the board that take a probe better.

If you're set on disassembling the motor, it looks just like the CR 240. There will likely be some tabs on the silver casing to lever out of the way, allowing the end caps to slide out. You can see these in my photos above.

Re: Uher CR 210 Cassette Recorder Check Out
 

Thank you Uncle Bulgaria.

Yes have checked the ground connections as far as I can to the Motor Drive board, on the Motor Drive board and out to the motor, all check out OK.

I tried pulling the pulley off with the motor in position but no joy, hopefully when the motor is out can get a better grip of it and it will come off.

David

Update - Yes have left it running for quite a while, often requiring manual help to restart it when it stops spinning

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.

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

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.

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

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.

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

Re: Uher CR 210 Cassette Recorder Check Out
 

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

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

Re: Uher CR 210 Cassette Recorder Check Out
 

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.

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

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

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

Re: Uher CR 210 Cassette Recorder Check Out
 

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.

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

Re: Uher CR 210 Cassette Recorder Check Out
 

Yes it's different for sure.

Lawrence.

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

Re: Uher CR 210 Cassette Recorder Check Out
 

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.

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

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

Re: Uher CR 210 Cassette Recorder Check Out
 

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

Lawrence.

Re: Uher CR 210 Cassette Recorder Check Out
 

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

Re: Uher CR 210 Cassette Recorder Check Out
 

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.

Re: Uher CR 210 Cassette Recorder Check Out
 

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

David

Re: Uher CR 210 Cassette Recorder Check Out
 

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...

Re: Uher CR 210 Cassette Recorder Check Out
 

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

Re: Uher CR 210 Cassette Recorder Check Out
 

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

Re: Uher CR 210 Cassette Recorder Check Out
 

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

Re: Uher CR 210 Cassette Recorder Check Out
 

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

Re: Uher CR 210 Cassette Recorder Check Out
 

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.

Re: Uher CR 210 Cassette Recorder Check Out
 

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