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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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Thread Tools |
12th Jun 2021, 5:00 pm | #21 |
Triode
Join Date: Jun 2021
Location: Wavell Heights, Brisbane, Queensland, Australia
Posts: 29
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
OK, cool, so that works fine. Thanks for walking me through that, I learned something new today.
I still think there's some kind of electronic issue in play because of how consistent it is no matter what I do, but if the problem is lubrication, where would suggest as key locations to check? |
12th Jun 2021, 5:10 pm | #22 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
What are the symptoms in Play? I thought it was just REW and FF that has a problem?
Lawrence. |
12th Jun 2021, 5:15 pm | #23 |
Triode
Join Date: Jun 2021
Location: Wavell Heights, Brisbane, Queensland, Australia
Posts: 29
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
Play functions are alright, but they do take one or two seconds to get up to speed in both directions. Maybe the torque issue is there as well...
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12th Jun 2021, 5:45 pm | #24 |
Triode
Join Date: Jun 2021
Location: Wavell Heights, Brisbane, Queensland, Australia
Posts: 29
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
Actually, I just remembered that I tested both of my motors in the deck without a belt on, just spinning freely and they showed all the same symptoms; slow to accelerate and not a good top speed in FF/RWD.
That leads me to think that lubrication isn't an issue (wouldn't hurt to do it though), but an electronics issue, unless I somehow coincidentally got two motors with the exact same problem, which I doubt. |
12th Jun 2021, 6:14 pm | #25 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
You could check the supply voltages to the motor circuit(s), I can't talk you through that just now as I'm in middle of doing the evening meal...(panic) but I will do later if no one else does, if the problem doesn't appear to be there then it's good practice anyway for learning to find your way around a circuit board and taking measurements.
Lawrence. |
12th Jun 2021, 6:25 pm | #26 |
Triode
Join Date: Jun 2021
Location: Wavell Heights, Brisbane, Queensland, Australia
Posts: 29
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
It's all good if you can't easily respond right now, as I'm about to go to sleep anyway, haha (it's 3:25am here as I type this).
My only worry about the servo amp board (if that's the motor circuit you're referring to) is that in FF/RWD modes that board is by-passed. It's also the second servo amp board this deck has had. My first and second motors both behave exactly the same with both servo amp boards, even after recapping them. Well, until I hear from you or anyone else here again, good night. |
12th Jun 2021, 6:55 pm | #27 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
To check out the supply voltages first check the voltage between the two points on the power amplifier circuit board on page 26 of the service manual where the Blue and Red wires connect to on the left hand side of the board up near the top, make a note of the voltage (DC) when in Play mode and then when in REW/FF mode.
Next measure the voltage between the two points on the servo amplifier circuit board (page 29 of the manual) that the Yellow and Blue wires are connected to on the top edge of the board at the far right, make a note of the voltage (DC) when in Play mode and then when in REW/FF mode. Hopefully that should tell us if there's anything significantly wrong with the motor supply voltages to the servo board in both Play and REW/FF. Lawrence. |
12th Jun 2021, 11:13 pm | #28 |
Dekatron
Join Date: Aug 2006
Location: Madrid, Spain / Wirral, UK
Posts: 7,498
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
I think it might be wise to fully exhaust the possibility that this is fault is mechanical in origin.
- Remove spool tables and lubricate bearings with light oil. Ditto motor bearing if you haven't already. - Check pulley is firm on motor shaft - been caught by that before! - Check state of guide posts in tape path. If these have seen lots of hours and are worn flat, or to the base metal, you'd be amazed at the drag this can put on the tape path. Fortunately many can be loosened and rotated 90º to expose new surface.
__________________
Regards, Ben. |
13th Jun 2021, 3:09 am | #29 | |
Triode
Join Date: Jun 2021
Location: Wavell Heights, Brisbane, Queensland, Australia
Posts: 29
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
Quote:
Power Amplifier Circuit - Forward Play Mode - 15.08v - Reverse Play Mode - 15.34v - Fast-Forward - 15.86v - Rewind - 15.71 Servo Amplifier Circuit - Forward Play Mode - 15.13v - Reverse Play Mode - 15.36v - Fast-Forward - 15.63v - Rewind - 15.67v |
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13th Jun 2021, 3:20 am | #30 | |
Triode
Join Date: Jun 2021
Location: Wavell Heights, Brisbane, Queensland, Australia
Posts: 29
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
Quote:
I don't doubt the possibility of a possible mechanical fault dragging it down, but considering the motor is slow to accelerate when the drive belt isn't even attached (i.e. spinning freely), I think it's more likely to be electrical. |
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13th Jun 2021, 7:40 am | #31 |
Dekatron
Join Date: Jul 2008
Location: Kington, Herefordshire, UK.
Posts: 3,675
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
I'd re-check the idler at this point - if the surface is shiny a good scrub with IPA should get you down to a softer matt surface, which will have greater grip. I had to deal with a slow-running TC377 where the cause was just this.
It's also well to remember that this is a sixties design intended to be capable of running off batteries - the available motor torque may have been limited for this reason by design, making the drive conditions critical for satisfactory operation. Last edited by Ted Kendall; 13th Jun 2021 at 7:47 am. |
13th Jun 2021, 8:23 am | #32 | |
Triode
Join Date: Jun 2021
Location: Wavell Heights, Brisbane, Queensland, Australia
Posts: 29
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
Quote:
There's a chance that the torque limit is true, but I've found a video of the same deck and in FF/RWD it runs much quicker than mine. I've seen so many videos of reel-to-reel repairs and they've all got idlers. Why did mine have to be different? Haha. |
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13th Jun 2021, 9:09 am | #33 |
Dekatron
Join Date: Aug 2006
Location: Madrid, Spain / Wirral, UK
Posts: 7,498
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
If the belts lack a certain amount of elasticity they may well be the cause. Did you replace them?
__________________
Regards, Ben. |
13th Jun 2021, 9:14 am | #34 |
Triode
Join Date: Jun 2021
Location: Wavell Heights, Brisbane, Queensland, Australia
Posts: 29
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
Yes, every belt (apart from the time counter belt) has been replaced. Though that improved different problems, like slipping, it didn't fix the speed issue.
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13th Jun 2021, 1:18 pm | #35 |
Dekatron
Join Date: Jul 2008
Location: Kington, Herefordshire, UK.
Posts: 3,675
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
Thorough cleaning of the pulleys is essential when changing belts to ensure correct traction - belt deposits are not always obvious and, even when visible, can be so even as to look like an intended strip of paint. Cocktail sticks, cotton buds and IPA are the tools of choice.
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13th Jun 2021, 1:35 pm | #36 | |
Triode
Join Date: Jun 2021
Location: Wavell Heights, Brisbane, Queensland, Australia
Posts: 29
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Re: Sony TC-560 | Slow Fast-Forward & Rewind
Quote:
I know what you mean by what would like like an intended strip of paint, haha. Fixing old floppy drives and CED machines has exposed me to that, big time. |
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