Emulator won't strike

Since you've tried the bulb go in this order .... Replace / swap: 1. Ignitor. 2. Pwr Supply Board. 3. Power Cap 4. Transformer/Main Logic (though unlikely if it is trying to strike in general)

Check to be sure that the retaining screws are both holding the lamp tightly at both the top and the bottom.

More than likely it is the big blue capacitor. Ignitor & Transformer failures are extremely rare in Emulators in my experience. PSBs are prone to issues, but usually go up in a lot of smoke when they do.

Hope this helps. :)

I found that if you run them @ 208, both Ignitor and transformer failures are far more likely than at 110. As Marty noted, the power cap could be the culperate as well, assuming unlike many people you actually replace your bulbs on time. Not doing so will guarentee premature ignitor failure and a nice mess too!

Thanks for the help.

Tried swapping capacitors this afternoon. No luck there, so it looks like it's probably the PSB.

I checked all of the fuses on the PSB, and they all measured good. I also tried measuring the voltage across the leads (the red and black leads coming from the terminal block on the right side of the board as you're facing looking at the back of the fixture) between the PSB and the Igniter/Lamp (after it stopped trying to strike). Seemed kind-of low, but i'm not sure if that's how it should be. I would expect, in a current-regulated supply, that the voltage would be at maximum if no current were flowing through the lamp, but it seemed to be below 10V. There was some voltage there, but not what I expected. Haven't had time to print out the PSB schematic, so I didn't dig too hard.

Ok, got to dig in a bit more on this now that i'm back from vacation. Looking accross P1 (the connector between the PSB and the igniter/lamp) I see about 50 or so volts DC at power up, and it tapers off to around 20 or so volts as expected. If I switch my meter to AC, though, I see about 50VAC superimposed on that DC voltage. (I havent' put a scope on it yet to see what it actually looks like). This seems wrong to me, since Xenon lamps are supposed to be DC lamps. I'm not sure if the AC is leaking backwards from the igniter, or if there's a bad rectifier on the PSB. It appears that most of the PSB is built using SCRs which i've never really been brought up to speed on, so I'm not sure how to determine where in the circuit to look for a failed device, or even how to recognize a failed device.

I think my next step might be to try the PSB after disconnecting it from the lamp/igniter, and see if there's still AC at P1. I'd rather not replace the whole PSB or Igniter if I can repair whichever is broken...

Anyone have any further input?


Jeff

Be very careful using volt meters and o'scopes on the ignitor/lamp side of the LPSU.

At strike time, there are voltages in the thousands of volts range. It can easily destroy your test equipment, and injure you in the process. As a general rule, if you don't have special test equipment, you don't want to be anywhere near the ignitor wiring at strike.

We have quite a few Fluke meters around here that have been destroyed by a strike.

Understood... that's why i tested just after strike...

I don't know about the emulators (never worked on one), but many LPSUs will try to re-strike the lamp if it doesn't get a stable arc on the first try.

Yeah, emulators try 4 or 5 times then give up... In any case, I don't think there should be AC on the lamp at any time (from my understanding of Xenon lamps, AC is actually damaging to the electrodes).

It sounds like you have a bad PSB. I would swap it out with a good working PSB from one of your other fixtures. It's the only problem that I have ever experienced with my 16 fixtures that I currently have. Call Don Pugh @ Light Parts! He can fix it for you for around $65.00 or so...

Actually, after further investigation, It almost seems like the problem is not with the PSB. There is a circuit that uses a stepped voltage from the mainboard to cycle the PSB from off to strike, to normal operation. This stepped voltage doesn't seem to be coming from the main board. Its worse than it was before, in that it doesn't get to the stike setpoint any longer. I think that circuit is failing on the mainboard. I'm going to first try to swap out mainboards and see if that fixes things. I'm pretty sure if the problem is the mainboard that I can figure out what's wrong and repair it. Its power supplies (especially those involving SCRs) that give me a headache.

When you say main board do you mean the logic board or the power supply board? The logic is located on the back plate of the fixture and the power supply board is mounted on the heat sink plate just below the fan. All functions for the lamp are from the power supply board with the help of the igniter. I would swap the power supply board first and see if that fixes your lamp strike issue. If not then swap the logic board.

I mean the logic board. There is a signal from the logic board to the PSB (P13 pin 4) that should ramp up from cutoff at 1/3Vcc to strike at 2/3Vcc. At the moment, that voltage never gets above 1/3Vcc, so the lamp portion of the power supply is never enabled. Its possible that the problem is IC4 on the PSB, but I'm leaning toward the part of the circuit on the logic board side at the moment.

Are you trying to strike the lamp with the controller or thru personality 1 or 2 on? Do you have any spare boards lying around for testing? Where are you located? I'm in southern California. I have plenty of spare logic and power supply boards (New)

Yes, both. I don't have any spare boards at the moment. I was going to swap logic boards between a working unit and the bad unit and see which one works when I'm done. If the working unit continues to work, then the problem is with the PSB, if the working unit fails with the logic board out of the bad unit, then the problem is with the logic board. I may be able to repair the logic board if that is the cause, but if not, I may be interested in a spare board (whichever proves to be bad) at that point. I'm in Seattle.