Express V5 2011 boot and ghost issue

[tpctech]

I have a Express that was built last year and has developed a strange issue.  The first issue I saw when testing my show is ghosting on the second have of the board.  if Ch9 is "on" Ch10 -16 ghost a little. (both sides are on the same phase)   The lights are 2 srings of LED lights channels 1-8 work fine. i tried a external dummy load and did not help.  This same controller sometime does not "boot" after power up.  I brought it in to the bench and could not recreate the ghosting but did recreate the not starting issue.  When the unit is powered on it goes through the normal boot sequence but does not "work" after the address shows on the display.  if it is rebooted by cycling the power it sometimes will startup ok.  It always will restart and work if the reset button is pressed. This is on a wired network and downstream Expresses on the DMX line work fine.

What I have done:
Checked solder joints
re-programmed PIC

I have not tried a PIC from another express.

Any thoughts?

KEN       

[rrowan]

It really sounds like a cold solder joint(s). I would reflow the solder and see if that clears up the problem. I am guessing that its colder outside  where you are seeing the problem then on your bench.

Check around the rs-485 chip an see if there is a problem there or swap out the chip to see if that helps with the non-working. This is the chip closer to the display. Or just a flaky pic but I wouldn't bet on that.

Rick R.

[combustionmark]

Its been raining here, has the express drawn any moisture, or condensation.

Try putting the express in the Frazer. And run some tests.

Lights just went out here, I can,t look up location, there is a resistor that has caused problems. It controlls how the express powers up, If it has a cold solder joint it can cause bad startups. Try reflowing resistors near the pic chip.

Ghosting can be caused by the lights, try a different express on them. If it continues, do the channel Led's light up.

Good luck