Resurrecting the KDSS-21

[mieletag]

Well, it has been a long road, but I finally got my KDSS-21 all fixed up and ready to go, or so I thought. Thank you to all who helped me get it this far. I finally got the tank, pump, air heater, and the rotary power switch all hooked up. I was able to procure a known good working controller/computer thanks to Combo52! Now for the unfortunate part. The display/touchpad board doesn't work. Well, it does; except for the plate warm, delay, energy save dry, and most important of all, the start button. Everything else, the S&S, normal, light china, quick wash, rinse & hold, and sani rinse and drain/cancel all work, it's just that the start button won't work. So I took the board out, and one of the traces that is inside the touch membrane is broke/smoked. So I found the appropriate pins and jumped it out for the start button. It worked!

So, that leaves me with a board that sort of works, but not really. The bad problem is, I can't really get to the membrane switch part. It is sandwiched in between the back PCB and the front cover. If I pry it apart, it will destroy the front cover.

Any ideas on how to fix this or if anybody has an old good board. Money is not a problem as I just want to get this thing fully restored and working properly.

Thanks again to all!

 

[mieletag]

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[mieletag]

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[mieletag]

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[mieletag]

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[mieletag]

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[mieletag]

and finally, the unit with the exposed door, rotary power switch on left, and controller on right.

 

[pdub]

Have you tried an electronics repair shop that works on computer circuit boards. They should know how to accomplish this if it can be done.

Best of luck.

 

[combo52]

Kdss-21 Control Panel Membrane

I will look and see if I can find a used one around, unfortunately I just saw one of these DWs going to the crusher the other week.

 

[mieletag]

Thank you both for your replies!

Pdub: Yes, actually I did take it to two different electronics shops nearby. The only problem is that in order to get to the thin film membrane, you have to pretty much destroy the front cover that has all the graphics on it to get to it. Otherwise, yes it would be very easy to repair.

Combo52: How unfortunate to see one of these uniquely controlled machines crushed. I know they were very troubleprone, but I just wanted to save a unique piece of history, even though they have one rinse, just the control system is so unique. If you happen to have a board, I promise to make a video and post it on this forum activating a cycle. A little bit of electronics and good old rapid advance timer sounds.

Thanks again for your help and insight!

 

[washer111]

Interesting!

I find the design of these dishwashers very interesting. 

 

If I interpret this correctly, then Computer in this dishwasher is merely in control of the Rapid-Advance timer, or does it just "activate" that cycle on the timer and give you some control over the factors of the cycle?

That "rotary power switch" also sounds like a pretty interesting piece of kit - could anyone explain that for me?

 

Whilst this post wasn't in the slightest helpful, this is such an intriguing machine design. I really do hope (and wish you well) in the complete restoration of your machine! It will be great to see this machine in operation  

 

[mieletag]

The way I understand it (please correct me if I am wrong) the rotary power switch is basically a rapid advance timer without the timer function. All the same contacts, just no regular timer motor. It has lobes in the rotary power switch to basically show the controller where it is in relationship to the cycle. I have the technician's guide that shows you can do a lobe count to make sure everything works correctly. Also, if I manually turn the RPS and reconnect power, the controller does an automatic lobe count and resets the RPS back to its home position. The controller board has I believe a 30 amp rated single pole single throw relay that sends power to the RPS for power to control all the electrical parts of the dishwasher. The RPS also has some signal wires going to the controller for the lobe posistion contacts.

When you select diffent cycles, it will turn the relay off until the RPS is in its correct program spot and then turn the relay back on. Otherwise, the pump (since it's reversing), would go from forward to reverse without pause or go through rapid on and off sequences otherwise.

A very neat piece of engineering, just a little finicky though LOL.

 

[pdub]

I'm keeping my fingers crossed that John L can find another control panel for you. You have put so much into this machine I'd hate to see it all for nothing. Even if you don't find the part right now, hang on to the machine as one just may turn up eventually when you least expect.

Best of luck to you.

Patrick

 

[combo52]

KDSS-21 Control Panel Found

Hi Chris, I have found a complete used control panel, contact me if still in need, John.

 

[firedome]

hope it's fixable...

it's one of KA's more interesting, if complicated machines, and why here we've concentrated on the simpler Hobarts, ala KDC series 17 & 18. In this case well worth doing because it is such a cool machine.

As one interested in restoring vintage Digital DEC PDP minicomputers, there comes a a point when things like NLA ICs and VLSI boards become overwhelming to deal with, to the point of being not realistic to do, so we've had to cut off machines later than around 1975. We're at the same point with some appliances. One begins to understand why one mantra of engineers is KISS.

Love to see videos of the control panel when it's operational.

 

[mieletag]

Thanks again everybody! Special thanks to Mr. John L (combo52)!

Will have a video on here hopefully very soon of this unique machine.

Thanks!

 

[jetcone]

Chris

does that machine have the whisper quiet listed on the panel? <span style="white-space: pre;"> </span>

 

[mieletag]

No, actually it is a real Hobart built unit. It has the acrylic (I think) logo on the left side. The tub is just the bare unlined non foil fiberglass. I'll get some video and pictures of it when I get the control board for Mr. Lefever.