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Genie circuits not working

Discussion in 'Design and technology' started by CoffeeTea, Apr 15, 2011.

  1. Hi,

    I've got a group who've each done a batch of Genie C08s with PTM switch inputs and LED outputs. The switches are fine but only about 15% of the LEDs are working. Some of the boards are a bit messy but most of them are neat, not bridged, not burned, and not dry. I can only conclude that the problem is with the soldering of the LED leg to the flying leads. What should I look out for? I may have taught this wrong but I've never had a problem before!


  2. Sorry if this states the obvious, you have soldered the LED the correct way round? Long leg to positive.
  3. Yes, I have double checked and all but one of the students have soldered the LEDs with the correct polarity.
  4. Try using a logic probe to test if the outputs on the chips are going high when they should. If they do then the fault is further down the line and if they don't then the fault could be with the programming.

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