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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 Jul 2021, 11:48 am   #61
Uncle Bulgaria
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Default Re: Uher CR 210 Cassette Recorder Check Out

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When you say "twined with" what that does that mean ? e.g. yellow to tape heads twined with black 3.
I was thinking of 'entwined' - some of them are twisted together and descend out of sight, presumably to the tape heads. I've worked out some of those now from the tape head contact numbers shown on the a2 and a3 part of the diagram, but now I wonder if the connections differ since your sheet that pertains to our models has different numbering.

The wire colours are very dodgy as some change colour along their length, and some seem faded. My diagram shows 'litze' wire labelled with German colour names for some of the board 600 connections, but they don't seem to relate to what I can see.

Now we know that the central lower contact of relay a is grounded via 602 is key, I think.
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Old 22nd Jul 2021, 1:06 pm   #62
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Default Re: Uher CR 210 Cassette Recorder Check Out

Yes totally agree about the wire colours, not always the same as shown and some of mine differ from some of your colours. Do not why some wires have Litze after the colour, to me the wires all look the same type.

As far as I can see all your relay contact wiring is the same as mine. The top black 4 way connector is definitely numbered 608 to 605 left to right as shown on the coloured drawing in Post 51. You definitely need your relay A a1 lower contact Green wire connected across to relay B a1 middle contact.

I have not yet worked out why I have 2 green wires at the top of relay A a2 contact (your have single wire Green 2).

David
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Old 22nd Jul 2021, 1:13 pm   #63
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Default Re: Uher CR 210 Cassette Recorder Check Out

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Quote:
Originally Posted by DMcMahon View Post
When you say "twined with" what that does that mean ? e.g. yellow to tape heads twined with black 3.
I've worked out some of those now from the tape head contact numbers shown on the a2 and a3 part of the diagram, but now I wonder if the connections differ since your sheet that pertains to our models has different numbering.
I think unlikely as the connections on your drawn sheet match up well.

David
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Old 22nd Jul 2021, 1:24 pm   #64
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Default Re: Uher CR 210 Cassette Recorder Check Out

Aha! That solves that mystery - one broken wire goes to the top of a2, the other end goes to 603 by my diagram. There are two wires on that contact because one goes to the board connection, the other to track 4 on the tape head.

The middles of a2 and a3 are the central contacts of the switch icons by the tape heads. I've been checking continuity by manually moving the relays, and that was the last piece of the puzzle.

See attached - no wonder there's confusion! This is the socket numbering on my diagram, and this is a snip from your PDF which is the same. L-R it's 601-604 red; 605-608 black and 609-614 grey.

Solenoid/relay "a" was fluttering as though it were on the edge of engaging when the play direction had relay "b" engaged. This stopped with freeze spray around the bottom left of board 700. There's a transistor there, but this is not shown on my service sheet as the layout is different.

The pause problem was simply the sprung contact on the back of the operating joystick being out of shape so it didn't contact the joystick.

Did you get your coloured drawing from SDS? I got my manual and diagrams there, but they didn't ask for a serial number. They did for my CR 240 to make sure I got the right edition of the diagrams.

I'll stop there as I've massively hijacked your thread. I'm very grateful for that painstaking work, thank you. I have no idea how the Uher factory solderers ever made all these tiny connections. It's possible, as I've replaced two of the wires now (with USB cable innards), but not easy. No wonder they were expensive machines. If you break any, send it my way and I'll resolder them for you by way of recompense.
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Old 22nd Jul 2021, 8:27 pm   #65
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Default Re: Uher CR 210 Cassette Recorder Check Out

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Aha! That solves that mystery. Well done good progress

- one broken wire goes to the top of a2, the other end goes to 603 by my diagram. There are two wires on that contact because one goes to the board connection, the other to track 4 on the tape head. So was this the wire that was broken in Post 44 that I referenced in Post 46 ?

The connection from 603 out to the centre pin of the ACCESS D type I am unsure what that is for ?

The middles of a2 and a3 are the central contacts of the switch icons by the tape heads. I've been checking continuity by manually moving the relays, and that was the last piece of the puzzle.

See attached - no wonder there's confusion! This is the socket numbering on my diagram, and this is a snip from your PDF which is the same. L-R it's 601-604 red; 605-608 black and 609-614 grey. Yes understand, good job for my coloured version.

Solenoid/relay "a" was fluttering as though it were on the edge of engaging when the play direction had relay "b" engaged. This stopped with freeze spray around the bottom left of board 700. There's a transistor there, but this is not shown on my service sheet as the layout is different. Have you got more than 2 transistors on the 700 board ?

The pause problem was simply the sprung contact on the back of the operating joystick being out of shape so it didn't contact the joystick.

Did you get your coloured drawing from SDS? I got my manual and diagrams there, but they didn't ask for a serial number. They did for my CR 240 to make sure I got the right edition of the diagrams. No it came (luckily) with my CR 210.

I'll stop there as I've massively hijacked your thread. No problem, it may get me motivated to progress my CR 210 further. I'm very grateful for that painstaking work, thank you. I have no idea how the Uher factory solderers ever made all these tiny connections. It's possible, as I've replaced two of the wires now (with USB cable innards), but not easy. No wonder they were expensive machines. If you break any, send it my way and I'll resolder them for you by way of recompense.
Hopefully will not have to take you up on that
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Old 22nd Jul 2021, 9:01 pm   #66
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Default Re: Uher CR 210 Cassette Recorder Check Out

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Aha! That solves that mystery - one broken wire goes to the top of a2, the other end goes to 603 by my diagram. There are two wires on that contact because one goes to the board connection, the other to track 4 on the tape head.
Forgot to ask was the wire also broken at the board end, i.e. the solder pad (that connects to 603) identified as gelb Litze (wire colour/type) as you show no wire on your sketch ?

David
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Old 22nd Jul 2021, 10:57 pm   #67
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Default Re: Uher CR 210 Cassette Recorder Check Out

Yes, there were a couple of broken wires, but I can't tell whether it's Litz or not. Certainly flexible and multi-stranded. It was awkward to solder, so it could have been individually insulated. Yes, one went to my 603, and part of it was indeed yellow. There was another I replaced because it was very frayed.

I believe the Access[ory] socket can be used for such things as remote start and time-activation switches.

Yes, I have a lot of transistors on board 700!

Some regressive steps for me, I'm afraid. Everything was functioning, and I tested the electrolytics on board 300. A number were out of tolerance and leaky, so I replaced those. On putting back board 300, I managed to crack the motherboard, the solenoid is fluttering again, and R67 has caught fire. I'd already replaced it as it had smoked before, but I can't work out where the short is at all. Enough for tonight, I think.
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Old 23rd Jul 2021, 9:45 am   #68
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Default Re: Uher CR 210 Cassette Recorder Check Out

Really unfortunate the motherboard crack and annoying the overheating R67, I cannot easily see R67, is this on the motherboard ?

Sorry was getting boards 600 and 700 mixed up, 700 has 10 transistors.

Yes know about the Accessory socket options but not sure about the centre pin connection for track 4 ?

A lot of work testing those small electrolytics, how are you proving that they are leaky, does your reformer box do low voltage so can measure the leakage current ?

Is the 700 layout in the PDF manual different to your board, I think the PDF layout is the same as my service sheet.

David
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Old 23rd Jul 2021, 11:02 am   #69
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Default Re: Uher CR 210 Cassette Recorder Check Out

I hope my travails make your check-out rather easier! I'll make all the mistakes first. I was rushing as I hoped to give it back during an event my friend's running today, so there's a lesson in there somewhere.

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Really unfortunate the motherboard crack and annoying the overheating R67, I cannot easily see R67, is this on the motherboard ?
Yes, it's in square G7 on the 1-99 board diagram, just under the large capacitors directly to the rear of the loudspeaker DIN socket. It's top left of the Drive Assembly diagram (164241000 version), and seems to exist for this purpose - burn out in case of a drive short as it is on the 9.5V rail supplying the motor and drive electronics.

It's now burned out three times, and I've worked out that it's because the pad where the wire link to 905 is soldered (+ side of C28, H4 on board 1-99 on the 164241000 diagram) has a bizarre fault. Metering this pad shows high resistance to ground, but applying slight pressure reduces this to only a few ohms. This also occurs when manipulating the wire to 905 when it's soldered to the pad, as if the slight twisting is shorting something out. As I have the bottom cover off, no doubt in some orientations on the desk this pad is slightly compressed by the wires beneath the board, causing the intermittent short.

The motor stops, and all the current is dumped through R67 and it burns out.

The crack is nowhere near as bad as my CR 240, where it arrived with a break across about a third of the motherboard and I had to jumper a few dozen tracks. It's just across T1, the HF bias area, so when I sort the short I'll have to see if Record works or if I need to jumper the couple of connections around there.

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Sorry was getting boards 600 and 700 mixed up, 700 has 10 transistors. Is the 700 layout in the PDF manual different to your board, I think the PDF layout is the same as my service sheet.
My error - some BCE connections are inline rather than in the triangle I've got used to seeing on these diagrams, so there are more transistors on the 700 diagram than I realised. I have two diodes soldered across the back which are different from their positions in the diagram. I think they're D713 and D714. Their marked positions on the component side are taken up with a large tantalum capacitor. I had to replace D713 as it was behaving as a resistor, and D714 had broken away from one contact. D713 is marked as BA181, which appears to be an obsolete normal diode so I used a 1N4148.

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Yes know about the Accessory socket options but not sure about the centre pin connection for track 4 ?
My F111 attachment has no pin 6, and the CR 240 circuit diagram has no pin 6 connection on the socket, so I'm at a loss here. I haven't got a CR 210 user manual which might describe possible specific accessories, alas.

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A lot of work testing those small electrolytics, how are you proving that they are leaky, does your reformer box do low voltage so can measure the leakage current ?
I'm testing them with a homebrew ESR meter, checking them against one of those bought LCR testers, and reformed/leakage tested in my Everyday Practical Electronics tester which goes down to 10V. It takes a little while to build up if there's leakage, so if it's hanging at 4V on the 10V range with 0.6mA of leakage on a 6V capacitor, there's probably an issue!
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Old 23rd Jul 2021, 9:44 pm   #70
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Default Re: Uher CR 210 Cassette Recorder Check Out

Thanks to your detailed info located R67, on my Service Sheet it has a special resistor symbol, I guess it is some sort of fusible/protection resistor. Strange about the shorting issue.

Strange the Tantalum capacitors being in the diode positions. When I originally stripped my CR 210 I found diode D12 (also a BA181) had one leg lifted/not connected, this diode is shorted out/grounded by rel a1 relay contact when relay rel A is energised.

The attached scan from the CR 210 Operating Instructions manual has information at 6.8 on the Accessories connector pin 6 connection. It has an erroneous English translation of "sub-standard films".

A straight Google Translate of the first German sentence in the manual -

Mit Ihrem Cassettengerät besitzen Sie die Möglichkeit, synchrone, impulsgesteuerte Schmalfilm vertonungen durchzoführen.

gives -

With your cassette player you have the option of synchronous, impulse-controlled cine film dubbing.

So do not know how "sub-standard films" translation was derived.


David
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Old 24th Jul 2021, 1:42 am   #71
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Default Re: Uher CR 210 Cassette Recorder Check Out

Aha! You've found it. I haven't got the user manual, only the service one. That looks like the reason there's a signal on Access pin 6 - film dubbing! Bizarre proof-reading...

Here's the back of my board 700 showing the diodes. I put the front up a few posts back so you can see if it matches yours, with the large tantalum where the diodes are marked on the later circuit diagram.

I suppose your D12 would have shown up as an error on auto-reverse.

I've fixed the shorting. It was a trying road, but logic got me there in the end. C28 goes from +9.5V to ground. In between the two PCB pads is a larger copper area for the attachment of the link wire to pin 905. After much gnashing of teeth, I worked out that there's a hole beneath that pad, and the copper lining of that hole is very, very close to the ground pin of C28 on the top side of the PCB.

On a bit of pressure being applied and flexing the PCB, the positive side of C28 brushed the ground plane and R67 was shorted. I've pulled off the C28 pad for the wire, and cleaned out the hole of copper. The 905 wire now goes directly to C28+ on the PCB hole.

All that remains is to manufacture new latching mechanisms for the loudspeaker, ALC and internal microphone switches, make a new loudspeaker switch, and follow the service procedures...
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Old 24th Jul 2021, 9:36 am   #72
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Default Re: Uher CR 210 Cassette Recorder Check Out

Well done on fixing the elusive short, must be a big relief for you.

I think the big Tantalum is C707 so should be there, looks like your Drive Control board has slightly different track artwork so the diodes have been fitted on the rear. See my board photos and layout drawing.

After rechecking mine it is D13 not D12 that is lifted at one end on the motherboard. I am going to leave it lifted to see what happens when I eventually get it going.

Making new switch latching mechanisms sounds difficult.

David
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