Look at the lamp sockets, more important the lamps replaced. Putting a perfectly good lamp into a bad
socket won't make it work. Putting a good lamp into a semi-working lamp
socket will make that lamp last on average 100 hours less each lamp until it stops working. You might have the lamp sockets that have expired.
Look at all the lamps you replace as easier to see that heat damaged B&W or Osram burnt in tattoo on the
base with heat damage and even arch welding on the bad lamp as an indication of bad
socket. Believe spec is every four lamp change the
socket, but short of doing
gaff tape
fixture count down on the
fixture notes (perhaps not a bad idea,) look at your bad lamps to see lamp
socket condition. Assuming clean filters and working fans, even a lamp over hours should still have the silver or gold coating on their bases that they came with. Short of that, above normal causes - filters, fans the
fixture might warn you about, or sockets which is often more heat damage to the bad lamp
socket.
Not aware of
DMX issues but am aware of upgrades that are frequently done, are these to the newest upgrade?
As a lamp inspector, I grew to love these lamps. I really can tell within about 100 hours how long one of these lamps had been in use - tested many times on this. Other than Willie' the tech person that kept putting good lamps into bad sockets inspite of numerous e-mails to teach him..... 1,000 hours was a reliable well maintained
fixture lamp life norm. In my opinion as opposed to those that use the
fixture... I really liked that
fixture.
Good luck and have fun with these fixtures. I grew up in the days before moving light and never learned them.