Film-Tech Forum ARCHIVE: No Spark from Xetron XH-JR

This is topic No Spark from Xetron XH-JR in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Skylar Kelly (Member # 9442) on 07-28-2016, 02:51 PM:

Hi Everyone,

A couple months ago I started a project to bring film projection back to Portland, Maine. We won a small grant, hooked up with a great team, and lucked out when someone gave us the semi-permanent use of a Kinoton FP16.

Up until Monday the system was working really well. We have an X3-N50 supplying power for the XH-JR, which is currently running an Osram 1000W lamp.

On Monday I laced it up for a tech-check before a screening of experimental works. Blower powered up, vane switch toggled, power supply thunked on... but no spark. I tried manual ignition - no dice.

The lamphouse has a small pilot light to indicate that the system has power - it's on. It does not have a voltmeter though.

The bulb looks OK. No discoloration.

The only thing that's changed since our last screening on July 3rd is increased heat and humidity. All the connections in the lamphouse look and feel solid, but is it possible that the climate changed something?

The manual said to check for a spark from the igniter with the power supply turned off at the distribution panel. I did so and did not observe a spark. Does this rule out bad diodes? If the igniter is dead am I up a creek?

There is a small acrylic cylinder on the bottom of the igniter. The manual says the spark gap is fully enclosed by the igniter, but what I can see through the very hazy material looks suspiciously like a spark gap. If this is the case, can it be adjusted?

The XH-JR seems to be an uncommon lamp house. Information regarding it is scarce, and the manual I have is for the XH-1000 / 2000 / 4000. It's been annotated for the XH-JR, so I would not be surprised if some of the information within is not entirely accurate.

Our next public screening has been advertised for August 5th. Hopefully I can get it online before then.

[Confused]

Posted by Richard Fowler (Member # 893) on 07-28-2016, 03:08 PM:

The XH Jr with the flip up chassis used an IREM ignitor with inclosed spark gap. The terminal strip on the side have several small capacitors attached.

Posted by Stephan Shelley (Member # 8587) on 07-28-2016, 03:11 PM:

Usually Xetron lamphouses have fuses or push button circuit beakers protecting the ignitor. Check them.With a meter make sure you are getting the 110 to terminals on the ignitor when you push the manual strike button. Some Xetron lamphouses have manual/auto strike switch. It needs to be in the manual position for the push button to work if it is there.

Posted by Skylar Kelly (Member # 9442) on 07-28-2016, 03:11 PM:

Interesting. I hadn't noticed the capacitors. Thanks Richard.

When I'm back at the cinema I'll post an image of the acrylic component I mentioned.

Posted by Skylar Kelly (Member # 9442) on 07-30-2016, 01:35 PM:

Hey Stephan - We just checked the terminals on the igniter: 120v when the manual strike button is pushed. We also checked what appears to be a fuse on the bottom of the ignitor for continuity - it's good. It can be seen in context on the right side of the first image and in detail in the second.

Posted by Richard Fowler (Member # 893) on 07-30-2016, 04:25 PM:

That is a sparkgap. The "fuse" type connector block can have contact issues and the gap in the tube may be too wide due to use/age. Power off CAREFULLY rotate the sparkgap to help with contact block issues. Test. If no improvement get a replacement sparkgap or if the gap has a screw set up, you can adjust the gap to make up for being too wide. This should be done by someone with suitable experience since dangerous shock hazard is an issue when working on this part of the lamphouse.

Posted by Stephan Shelley (Member # 8587) on 07-30-2016, 04:42 PM:

The spark gap there when pulled out should not show continuity. If it does something is shorting it out.

Beyond the spark gap there not much in the way of replaceable parts. You should be able to find XH2000 ignitors and retrofit it.

Posted by Jim Cassedy (Member # 4115) on 07-30-2016, 05:23 PM:

I would also check to make sure all the safety interlocks are working properly.
I've had something as simple a the little 'vane' falling off the microswitch in
the exhaust stack keep a show from starting. All the "go" lights on the console
were lit, and the voltmeter indicated power to the bulb, but the 'vane switch'
kept power from reaching the igniter.

I've had this happen on both film & digital projectors.

Posted by Skylar Kelly (Member # 9442) on 07-30-2016, 06:06 PM:

Jim - All the safety interlocks (that I'm aware of) check out. Thanks!

Stephan - Shows continuity when it's plugged in, none when removed from the circuit. There are a couple of IREM igniters on eBay right now. This one looks almost identical to what's in there now, but I'm not certain of the specs.

Richard - Rotation did not solve the problem. After powering down and unplugging I removed it. There is one set screw on each end. Should they be adjusted in equivalent increments?

I assume there are capacitors inside the box that could smoke me, so I'm using extreme caution when handling the spark gap.

Posted by Skylar Kelly (Member # 9442) on 08-01-2016, 12:06 PM:

Adjusting the spark gap was unsuccessful.

Looks like a retrofit may be in order.

The model number of the current part is A-9550-S . The part on eBay is AS-9550. Same thing, perhaps, but the former was made specifically for Xetron?

Posted by Leo Enticknap (Member # 534) on 08-01-2016, 05:33 PM:

Not related to your rectifier, but as you're running an FP-16, FYI, if you're ever in need of new gate plates and runners, Rosbeek Techniek in The Netherlands makes and sells aftermarket ones.

After Kinoton stopped making them, a I know a few of FP-16s that have returned from the almost afterlife thanks to these!

Slightly OT, but we have the Rosbeek conversion Kinoton for Norelco (DP-70) readers to dual red light/white light for archival print use, and they're fantastic. I've never heard a 1940s RCA Duplex track sound so warm yet clear than with this white LED.

Posted by Skylar Kelly (Member # 9442) on 08-01-2016, 05:37 PM:

Thanks Leo! Thankfully I have a few runnerstrips and one extra skate, but while Rosbeek is still making them I might be wise to stock up...

Appreciate the tip.