Prusa i3 Heated bed small led

Little confused on the supposed leds on my heatbed. From readings I guess this is actually leds that should light in some fashion.
My "leds" has been totally dead from start .... light wise.
If I measure over them with power off I get 994 Ohm, both directions .... so not sure if that is sign of good or bad.
By a standard diod that would mean bad. Is it same for led diod ??

Anyone got this things giving light ?

My Leds

Heated bed is warming up ok. Just real slow I think. Been adding some more heat isolatiion under it but seems I still lose a lot of heat to the metal under it.
So when printing I seldom get over 100 degree C .... which is a little disturbing, going for 110

Ha det gött
Bosse

Edited 2 time(s). Last edit at 04/29/2014 01:51PM by sidhabo.

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Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden

They should be on the board in opposite directions to detect power with either polarity, so if you aren't disconnecting them from the board, measuring conductivity either way should be expected.

I'd check that your resistor works and that you have a 1.7V+ voltage drop across the leds. If so, then I'd try touching a bigger led in parallel to the existing leds.

Thanks DaveX , that was good advise Let you know how that goes
Ha det gött
Bosse

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Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden

Had 12 V over led so I guess they are broken. Might have put on too much heat when soldering heat feed cables ....
I'll get a led and see if I get that going .... just for fun. Not all that important when you have LED panel displaying current temp.
Ha det gött
Bosse

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Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden

I never even put LED's on my bed. It's just a visual indicator that the bed is on.