By-pass surgery on the eumig 824

[Paul Adsett]

DSC03017.jpg Eumig designed great projectors, but sometimes they got a little too clever. I don't know for sure if Eumig designed and made these special sliding switches themselves but I have had to replace all the main switches on my three 900 machines with standard rocker switches located on the rear of the projector chassis. The Eumig sliding switches are tiny and , at least here in Florida, they just corrode and seize up.
Today it was the turn of my 824D, which has a flimsy little sliding switch more suited for low voltage applications. The chance of finding a replacement is just about zero on any of these machines, so the simple fix is to wheel the machine into the operating theater for by-pass surgery.

[Brian Fretwell]

Maybe it is current, not high voltage, that is the problem. In Europe these switches would be passing half the current (with twice the voltage) and as power is (current squared times the resistance)/2 the higher current in the USA may burn them out sooner if there is slight corrosion.

[Osi Osgood]

So, what exactly do these switches do? ( Inquires the owner of two 926's)?

[Paul Adsett]

These sliding switches are dual pole single throw switches which switch the incoming mains AC power to the machine. They are not essential, just a convenience, in fact most of the 800 series do not have a mains switch installed. The switch in the 824 is different from the ones in the 900 series, but the principle is the same. The purpose of the switch is just to enable you to turn the projector off without the need to unplug it from the wall. For some reason Eumig chose to mechanically interlock these switches to the main rotary control knob - I don't see the necessity for that.

[Osi Osgood]

Thank you, Paul.

[Paul Adsett]

There is actually just about enough room to fit a small rocker switch or toggle switch in that area of the 824D. The wiring is all there in place to do it, but it involves drilling a large 3/4 ins dia hole into the left end of the chassis which I hate doing on an assembled machine. Something I may attempt later though. Too bad Eumig did'nt just go that way.

[Paul Adsett]

Well I was walking around Lowe's yesterday and came across this switch in their electrical section:

https://www.amazon.com/Gardner-Bende...s%2C107&sr=1-1

I thought this might be ideal as a replacement for the broken OEM mains switch on the Eumig 824 so I purchased one . Low and behold it is a perfect fit into that little compartment on the projector, and the good thing is you don't have to do any drilling, cutting, or filing of the projector chassis. Just pry out the little plastic I 0 clip and this baby slides right in! And the switch is prewired which really helps a lot. The original sliding switch is a DPST switch, this new one is an SPST switch which I have wired up to just interrupt the incoming line level 115v voltage. The neutral wire is now always connected. I have retained the defunct old switch in place purely for the convenience of providing the 4 soldering posts, it now serves no other function.
It works great when wired as shown, and is so much more robust than that little toy OEM switch. The switch arm is quite short so it looks pretty close to the original little arm, but of course the new switch is not mechanically interlocked to the rotary control knob anymore which is totally unnecessary anyway.
Although its not really required its nice to have a main switch back on this magnificent projector, as Eumig intended.

[Lee Mannering]

Good Paul. The original switches seem to sort of dry out so I give them a good squirt of switch cleaner.