EDS 500 direct drive motor speed issue

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mrow2
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EDS 500 direct drive motor speed issue

Post by mrow2 » 30 Jan 2019 22:10

Who has done the capacitor replacements on the EDS 500 motor? Any suggestions or thoughts about it? The symptom is that the speeds were ok, then the other day it began running at 64RPM. Speed control and 33/45 switch were cleaned with DeOxit, no change. One of my customers is asking me and I am interested in knowing more anyway. The board seems like a capacitor replacement would be practical. AFAIK he did not touch the VR controls on the board yet. -- D

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Re: EDS 500 direct drive motor speed issue

Post by dualcan » 30 Jan 2019 22:21

Hi Don,
Which unit are we talking about?
Cheers,
k

mrow2
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Re: EDS 500 direct drive motor speed issue

Post by mrow2 » 31 Jan 2019 02:15

Stupid me! It's a 621. Have researched and seen pics of the board; appears to be a lot simpler than the EDS1000. Since this post I found the list of replacement caps, and the owner has already come back and said there are some differences between that and his comparison. Maybe I am misreading it?. The owner reports he did clean the VRs as well, and then reset them in marked positions.

Supposedly, this is the list and the corrected information, if in fact the issue is capacitors (seems probable to me):
For the 621 - EDS 500- the caps are:
C1 47µF/ 25v stabi (7.5V "ROE"- poor)
C2 220µF / 16V und C3 0.47µF / 16V "ROE"- poor
C3 470µF / 35V
C4 470µF / 35V
C10 470µF / 35V
C11 100µF / 16V
C12 0.68µF / 35V

X2 (Rifa) Safety caps:
Cxx 10 nF (no number/ across power switch
C51 68 nF (for strobe)
C52 47 nF (for strobe)
If cracked > change them.


For the 621 - revised:
C1 47µF/ 25v stabi (7.5V "ROE"- poor)
C2 220µF / 16V und C3 0.47µF / 16V "ROE"- poor (Actually 220µf / 10v)
C3 470µF / 35V (Actually 0.47µf / 35v)
C4 470µF / 35V (Actually 0.47µf / 35v)
C10 470µF / 35V (Actually 0.47µf / 35v)
C11 100µF / 16V (Actually 10µf / 16v)
C12 0.68µF / 35V

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Re: EDS 500 direct drive motor speed issue

Post by dualcan » 31 Jan 2019 19:03

Hi Don,
I just went over the diagram, a new 244 477 board and a 604 which I also need to play with...
As you may know, the EDS 500 and its board is used in many units. The 604 is the manual twin to your 621.
Tink posted an excellent close up of the board here:
download/file.php?id=54736&mode=view
I also took these shots:
The first is a NOS board 244 477:
244 477 1.JPG
(48.55 KiB) Downloaded 115 times
In the second pic, I circled the tantalum caps in red, which are on the turntable mounted board, but not on the replacement board. As both boards are factory, it means standard caps are ok to use on this motor and don't need the higher tolerance accuracy of the tantals.
Also encircled in green on both boards, are the notorious ROE caps, which must be replaced anytime/anywhere you see this brand, as they are a sure fail.
244 477 2.JPG
(68.68000000000001 KiB) Downloaded 127 times
Assuming you cleaned trimpots R8 (10K), R9 (22K) and pitchpot R19 (2.5K), and the motor is still off to the races, then follow a procedure that our colleague Peter over at dualboard worked out.
Here in translation is his outline:

Board to motor: Pin 8.1 is positive (red cable); pin 7 is negative (blue cable)
Power box to PC board : positive (red) to 8.2; negative (gray) to 1.3. Voltage is 20.5 on those two points.
For units that speed up, clean the trimpots R8 (10k) R9 (22k) and pitchpot R 19( 2.5k) first.
If it still spins up , measure the tach coil from the motor (two brown cable on pins 1.1 and 2) which should be around 24 Ω:
244 477 4.JPG
(56.24 KiB) Downloaded 104 times
If the coil is open then the motor is trash.
C1 is a stabilizer for the 7.5 volts, which is the working voltage for the electronic circuit board.
C2, C3, need to be checked and if C2 (occasionally also C13) is a ROE (Roedenstein) brand any colour, always replace.
C3 can be a tantalum, but not necessarily so.

Here are some of the blue tantals in side view:
244 477 3.JPG
(53.55 KiB) Downloaded 101 times
C13 is used to level out any possible motor brush hesitation and to catch induction spikes.
If C2 and C3 don't eliminate the speed increase and tach coil is ok, then change the two Ic's.
In most cases only the Cmos 4069 is at fault in which an inverter quit.
The timer 555 normally is capable of handling overloads but susceptible to shorts on its output, especially if one of the inverters, going to the motor driver, called it quits.
These chips should still not be hard to get.
I also went over my old caps list which you had posted and corrected the values, as found on both boards:

C1- 47µF/ 25v stabilizer ("ROE"- poor quality- change)
C2- 220µF / 6.3v
C3- 0.47µF / 63v ("ROE"- poor quality)
C4- 0.47uF / 63v
C10- 0.47 µF / 63v
C11- 10µF / 16v
C12- 0.68µF / 63v
C13- 47uF / 50v
C55- 1000uF / 40v (in power box)

As for voltages, the maximum going in the board is 20.5 volts, so if a cap is rated at 63 volt and you have a 40 or so rated, that's not an issue. As well, you can always go a bit higher in the voltages (25v for 16v etc).

X2 (Rifa) Safety caps:
Cxx 10 nF (no number/ across power switch
C51 68 nF (for strobe)
C52 47 nF (for strobe)
If cracked > change them.

Lastly, never forget that there can be pesky / loose solder joints to play havoc...
Hope this helps,
Regards
k

mrow2
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Re: EDS 500 direct drive motor speed issue

Post by mrow2 » 31 Jan 2019 21:10

Hi This is great, and I'm forwarding this information right away. He will be appreciative, as am I. The explanations are excellent. If there is any chance it is repairable, this should do it. It was running fine, then suddenly locking in at the higher speed. Hopefully this thread will have value for other owners of the EDS500 too. Cheers, Don

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Re: EDS 500 direct drive motor speed issue

Post by scorpio333 » 21 Nov 2019 01:18

Thanks for this thread, I had a 621 follow me home, it's running at 103.9RPM. The table is in fairly good shape and unmolested, even some of the original pimple is there. However, somehow board 244 477 was detached from where it should be. The back of the board is a bit of a mess, I dare ask if the boards are still available??


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Re: EDS 500 direct drive motor speed issue

Post by Tinkaroo » 21 Nov 2019 13:55


scorpio333
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Re: EDS 500 direct drive motor speed issue

Post by scorpio333 » 21 Nov 2019 18:50

Tinkaroo wrote:
21 Nov 2019 13:55
Organ Donor Parts has one here:

https://organdonorparts.com/Dual-CS-604 ... egoryId=-1
Saw that one, was hoping the board would be available separately. Looks like dualfred may have a few boards that would "work" but would need a mounting solution and they're a bit more expensive than organdonor's motor/board.

My motor checks out good at 24.6ohm, so I tried unsoldering and resoldering a few joints. The table starts much slower, but within 30 seconds or so it's full tilt 104rpm.

While I thought this table was untouched underneath, someone may have already replaced some caps?
https://uniim1.shutterfly.com/ng/servic ... 97/enhance

Question now is, should I order caps and try to save this board? Or, get the organ donor motor/board which will most likely need the caps as well?

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Re: EDS 500 direct drive motor speed issue

Post by scorpio333 » 29 Nov 2019 16:56

I got the organ donor motor and board, the board had ROE caps so I replaced those. Installed and working at correct speed. On part 238034 the red and green leads popped off. For some reason soldering those leads back on was a nightmare, solder just wouldn't stick to the pads and then the board snapped. Got it back together and had to tinker with the tab alignment. All done, just needs degreased, cleaned, regreased, steuerpimpel, etc...

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Re: EDS 500 direct drive motor speed issue

Post by scorpio333 » 29 Nov 2019 21:13

Also should have added, the board that was in the table when I got it is toast. I thought no one had been inside this table, I was very wrong on that. 99% of it looks untouched underneath. The 244 477 board was removed from the motor and left dangling. The clamps that hold it in place were chewed on by an unknown metal eating monster with sharp teeth. That same monster should have its soldering gun taken away, the underside of the board around C13 is destroyed.

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