Results 1 to 4 of 4

Thread: Tips on tracing a short

  1. #1
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,248

    Default Tips on tracing a short

    Whilst fitting some new modules in my 8W projectors, I seem to have picked up a short to ground on one of them.
    It's manifesting as odd modulation. I'm using a DS3 colour correction board and if I set the thresholds just off, then pull the ILDA cable out, all the lasers come on.
    If I measure DV volts between bottom plate of projector and optical deck I get 1.1V
    |
    However, I've been plugging and unplugging bits to see when it changes, but I've started going round in circles a bit.
    I've unbolted the galvo amps and lifted them off in case they've shorted to the heatsinks, and removed the drivers too.
    |
    Anyone got any hints and tips on tracing this? I've put it to one side for the moment, to finish work on its sister projector, but my next step is probably going to be to strip it out and rebuild it, checking as I go where I can.
    Frikkin Lasers
    http://www.frikkinlasers.co.uk

    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

  2. #2
    Join Date
    Feb 2007
    Location
    Fort Mill, SC USA
    Posts
    1,490

    Default

    Over the years, I have seen two PSUs that failed and produced those symptoms. It may be worth swapping them out one by one if you have the spares available.

    Good luck tracking the problem down!

    -David
    "Help, help, I'm being repressed!"

  3. #3
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,248

    Default

    Thanks David, I did wonder if one of the PSU has developed a short to its case or something. I do have an identical projector I can swap bits over for, but its a good strip down on each of them to get parts in/out.
    Frikkin Lasers
    http://www.frikkinlasers.co.uk

    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

  4. #4
    Join Date
    Feb 2007
    Location
    Fort Mill, SC USA
    Posts
    1,490

    Default

    Yeah, I don't like to track that kind of stuff down. It's much more satisfying when you are upgrading a projector as opposed to fixing one that was just fine earlier.
    "Help, help, I'm being repressed!"

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •