Simple Help Need for Power LED indicator on Sigma 22

  1. ivanrocks321
    MVIMG_20171116_220311.jpg MVIMG_20171116_220404.jpg MVIMG_20171116_220304.jpg Basically a while back my sigma 22 had issues and was repaired but the LED for the power switch was not attached. I would like to get it setup since I like to know when the unit is one so it easier for me to remember to turn it off. I have some pics if anyone can tell me what wire goes where im a super noob but I think this an easy enough task for me after I know what goes where.
    Last edited: Nov 17, 2017
  2. ivanrocks321
    woops forgot to add pics!
  3. Pars Contributor
    What power switch are you using? It looks like there is another pair of wires coming from the switch that are disconnected (visible in the pic with the IEC connector.
    What voltage is the sigma22 set for? And what voltage can the LED take? If sufficient (LED V), you could just connect it to one of the V+/Gnd outputs of the sigma22. You might need to add a resistor in series with V+. Without validating the switch and pinout of it, I can't tell if it is wired to the correct terminals or not.
  4. tomb
    Your power switch is 12V rated. The black and orange leads that are bent back and disconnected (2nd pic) are the LED leads from your switch. I suspect that they are intended for the LED pads on the Sigma 22, which are right in front of the green terminal block in the middle of the two long black terminal blocks. However, there's something going on in that position shown in the first photo. It looks like there's some electrical tape or some sort of black plastic covering the LED pads in front of that green terminal block.

    After cleaning up whatever that black plastic is - if you are VERY careful, you might try pushing those leads into the LED holes on the PCB. (Do this with the power OFF.) Then try turning the power on. If the switch lights, note which wire is in which hole and solder them in place. If the switch doesn't light, turn the power OFF, then switch the wires and try again. If the polarity is reversed on the LED, I doubt seriously you are going to burn the LED out - as long as you don't leave it on too long.

    Anyway, just a suggestion. If you had it repaired from a reputable service person, it really needs to be returned to finish the work, because they left things hanging.

    P.S. Not being that familiar with the Sigma 22, I'm a bit surprised there's no polarity shown on the LED pads. I can't find any looking at AMB's website on the Sigma 22. The polarity is shown in his schematic, but not on his drawings/pics of the board. At any rate, you might "assume" that the orange lead for the LED is positive and the black lead is negative. Looking at the schematic, the positive lead (orange) should go next to R16 and the negative (black?) next to R17.
    Last edited: Nov 18, 2017

Share This Page