Film-Tech Forum ARCHIVE: ORC M1000 Lamphouse: Trying to find the cause of sudden failure

This is topic ORC M1000 Lamphouse: Trying to find the cause of sudden failure in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Larry Davis (Member # 609) on 09-01-2004, 08:01 PM:

After 4 years of problem free use, my ORC M1000 failed suddenly. When I turned on the unit I heard an electrical sizzle and flash from inside the lamphouse. This was very abnormal. The bulb did not ignite. I turned the unit off. When I reset the circuit breaker and tried again, the button popped out after about 2 seconds and I heard a hum, but that was it. I didn't hear any "tap" that would indicate the bulb was being struck. Today, I removed the top cover and looked around. I didn't see any scorch marks on anything, including the circuit boards. The wire on the front anode is not touching the mirror. It's about an inch away from it at its closest, exposed point. The shielded part is about a 1/4 inch from the mirror.

I am really scratching my head at what the problem is. A friend mentioned it might be the igniter board. A different member here mentioned in another forum that the diodes may be at fault. Thoughts? I have read quite a few posts here about the ORC M-1000 and the diodes are often mentioned as the cause of failure. I appreciate any and all input. Bear in mind I have zero background in electrician type knowledge, so I am at a bit of a disadvantage.

I appreciate any input...

Posted by Michael Labbe (Member # 148) on 09-01-2004, 08:39 PM:

I worked on one of those a few years ago, and it took a long time to find the culprit. Mine was reacting the same way you mentioned. As soon as I would raise the circuit breaker you would hear a loud hum and a few seconds later the breaker would snap off. I looked at the SCR and control boards but they were operating normally. The problem ended up being the diodes. Not so much the diode itself but the way it is mounted in the lamphouse. The base of the diode screws into a bracket that is insulated from the transformer case. On the diode there is a small plastic sleve and a mica washer that help keep the diode in the correct position so shorting doesn't happen. In my case the small plastic sleve around the threads of the diode and the mica washer had broken down allowing the diode to arc to ground. After repairs the unit is once again running great. [Smile]

Posted by Mark Gulbrandsen (Member # 72) on 09-01-2004, 08:44 PM:

It could be as simple as the positive lead touching one of the front dowser blades, or you may have a shorted diode. Quite frankly the loud hum is a dead givaway that one is shorted. They are unfortunately at the bottom of the unit in the back...under the main transformer. This requires tearing down the unit. This is easy for those that have done it and can be done in about 10 min. However if you have not done it before you're better off leaving it to someone that has some experience with them. Of cource there could be another problem but as fast as the breaker pops it sounds like a shorted diode. TIP! For greater reliability replace them all with 85 amp stud mount(glass passavated type if possible) and while you're at it also replace the blocking diode as it to will eventually fail from heat stress. Generally when I go through one I replace the electrolytics, the caps on both circuit boards and the main and blocking diodes. A total rebuild is not much in parts cost, less than 100.00 and a couple of hours of an experienced techs time.

Mark @ CLACO

Posted by Larry Davis (Member # 609) on 09-02-2004, 12:46 AM:

Hi Michael,

I removed the rear plate/cover (not completely because there's a lot of wires hooked up back there) and I think I found that bracket and the diodes. I am a little concerned about electrocuting myself with any residual charge so I didn't touch the components. But I think I found the diodes on top of the transformer. I'm glad it is a problem that can be fixed. I guess you sent it out to a pro for repair? I really like this lamphouse and other than this one problem it has worked great.

Hi Mark,

From the way you describe it, it sounds so simple but I have no experience in this area. As you say, I would prefer to use the higher quality and more robust parts. Maybe there is a tech in the tri-state area who could handle this repair? Of course I would be glad to pay for the service. Maybe there is a business in the NY/NJ/CT area that handles this kind of thing?

Thanks for your help!

Posted by Stan Gunn (Member # 554) on 09-03-2004, 06:26 AM:

Hi Larry

I would check the blocking diode on the r/h side of the panel

between the front and rear section, they often short out to the body under the diode itself. [eyes]

Posted by Larry Davis (Member # 609) on 09-03-2004, 09:55 PM:

Hi Stan,

Thanks for the tip. I was contacted by a kind member who may explain how I can check the diodes on my own. [thumbsup]

Posted by Michael Schaffer (Member # 1204) on 09-04-2004, 05:20 AM:

Who "may" explain? That sounds like it is a great mystery that the unnamed member is about to divulge...Just get a multimeter with a basic diode checking function, or measure the resistance in both directions, that's it.

Posted by Stan Gunn (Member # 554) on 09-04-2004, 06:47 AM:

There are some that are brilliant in their own fields, and are not afraid to ask for advise in things that they are not sure of.

There are others that have nothing usefull to say, except to ridicule those who seek information for themselves that may also assist others.

Then there are those that post any [bs]

to boost thier post rateing. [thumbsdown]

Posted by Mark Gulbrandsen (Member # 72) on 09-04-2004, 07:12 AM:

"Then there are those that post any [bs]

to boost thier post rateing [thumbsdown]

."

You mean lIke the two posts directly above this one....... [Roll Eyes]

Larry,
Would you please post what you learn about teoubleshooting the 1000 after you get your first big jolt from it. There are many other techers that also own them and they are dying to get their first big jolt from their 1000's too. I'm sure that everyone else here is also dying to know.
Thanks!

Mark

Posted by Stan Gunn (Member # 554) on 09-04-2004, 07:26 AM:

Mark

YES

Posted by Steve Kraus (Member # 476) on 09-04-2004, 10:12 AM:

Mark, I don't understand the point of your comment. Are you saying he should not be told how to check diodes?

This forum is about the free exchange of information. Always give the facts straight, and, if you are unsure of a person's experience level, explain what the risks of injury to self or the equipment might be. I don't want to see this turn into, say, alt.hvac, where if they don't think you are one of them any query is answered by Call your local technician.

Posted by Mark Gulbrandsen (Member # 72) on 09-04-2004, 11:26 AM:

Steve,
Geez, loosen up a bit... Its good for you... You take things TOO seriously! The guy above you seemed to get the point.... [thumbsup]

. Aside from exchanging info this site is also good for telling someone to loosen up a bit. And that "kicks ass". Quote stolen directly from Joe!

Mark

Posted by Steve Kraus (Member # 476) on 09-04-2004, 03:11 PM:

::makes note to eat more roughage:: [Eek!]

Posted by Michael Schaffer (Member # 1204) on 09-04-2004, 04:23 PM:

quote: Stan Gunn
There are some that are brilliant in their own fields, and are not afraid to ask for advise in things that they are not sure of.

There are others that have nothing usefull to say, except to ridicule those who seek information for themselves that may also assist others.

Then there are those that post any to boost thier post rateing.

Why are you getting so aggressive? I told the gentleman from NY what the easiest and quickest way to solve his problem is. If he buys a multimeter - which is not expensive and which he can use in many other situations - with a diode testing function, then he can quickly check the diodes, there is no big mystery about that.
The meter will have a booklet which explains the diode checking function.
There are other ways of hunting down the bad diode, like checking the temperature or using an ampere clamp, but as a first step, the multimeter way is easiest and cheapest.

Posted by Larry Davis (Member # 609) on 09-04-2004, 04:39 PM:

I put on some rubber gloves and grabbed my neighbor's cat. I placed it against the things marked "capacitors". The cat stiffened up for a few seconds and now it seems like it's passed out. Is it safe for me to touch the inside now?

Posted by Michael Schaffer (Member # 1204) on 09-04-2004, 04:54 PM:

You can also check that with the multimeter if you check for DC voltage between the lamp cable leads. Normally, you will see the voltage bleed down as the capacitors discharge. Whenever you are unsure if it is safe to touch anything, check for AC and DC between the touching point and ground. Keep one hand away from any grounding points, like the frame.

Posted by Steve Kraus (Member # 476) on 09-04-2004, 10:52 PM:

Note that those big caps are not storing high voltage. But you don't want to get a nasty surprise if you accidentally short one. The voltage won't be high but the oomph (technical term) might weld your screwdriver.

Posted by Mark Gulbrandsen (Member # 72) on 09-05-2004, 09:50 AM:

The voltage won't be high but the oomph (technical term) might weld your screwdriver.
____________________________

I've just been sitting here waiting for a line like this to appear from these guys....... They've been watching far too many Mr. Wizzard reruns lately.....

Now Larry, Before you touch that gizmo you need to open the kneuten valve and let out the oopmh! With these fellows assisting him we will be likley to see other huge technical words such as gizmo, kaneuten valve, whatchamacallit, and firebottle being used freely on this thread....... [Eek!]

What I think Steve meant to use was the word Joules...... [Cool]

Mark

Posted by Steve Kraus (Member # 476) on 09-05-2004, 10:18 AM:

Well, oomph can be measured in Joules, yes.

But you misspelled Kneuter valve.

Posted by Larry Davis (Member # 609) on 09-05-2004, 04:29 PM:

Guys, re: discharging caps, what do you think of the method advocated here: Safely Discharging Filter Capacitors

quote:
Using a resistor between the postitive end of the cap to ground. It's a very simple tool to make with a pair of insulated aligator clips, some wire and a resistor. I have heard several different sizes of resistors to use. Personally I use a 2 watt 10k resistor as called out in Torres book-Fig 1. Wire it up as shown, make sure the aligator clips have some good insulation on them. As for the wire, I prefer a 600v rating. Which should safely cover most applications. Use a 2 watt 10k metal film or wirewound resistor. That should last longer and be safer in the long run. Make sure to cover any expose wire with electrical tape.

When using this discharger tool, you should hook one of the clips to ground first. Then attach the other clip to the positive terminal of the capacitor. Since the caps are all connected, this should discharge all the capacitors. You'll notice on some designs there is a capacitor on the other side of the Standby switch. Personally I leave the standby switch in the on position to make sure everything drains.

I'd like to know if the idea is sound and if I need other, higher rated components. I have the digital multimeter. I have already tested one diode on another M1000 I have (it is broke and was given to me "for parts"). I do not want to screw this up and I am not going to charge (no pun intended) into this. The two things holding me back are 1) the fear of being electrocuted and 2) the fear of doing more damage to my lamphouse. As soon as I know it is safe to get inside, I will test the diodes. I do appreciate the sincere advice, thanks. No, I did not hear back from the member who offered to explain how to check diodes. At this point, I think it is irrelevant.

Posted by Michael Schaffer (Member # 1204) on 09-05-2004, 05:46 PM:

The power supplies has resistors which more or less quickly discharge the capacitors. When you switch it on and off again, then place the multimeter probes across the lamp connectors or the capacitors, you should see the DC voltage slowly go down. Once it has bled out, you can attack the PS. Just check for AC and DC voltages everywhere you are going to touch to be safe and build confidence. Also remember to switch the breakers to the lamphouse off. You should locate and check the incoming AC wires - someone who worked on the PS before you may have decided to bridge the breakers, I come across that in the field sometimes [Eek!]

Look at the schematic in the manual available from www.film-tech.com and compare it to what you see to familiarize yourself with the components and where they are.

Posted by Mark Gulbrandsen (Member # 72) on 09-05-2004, 08:21 PM:

I want to point out that on some Model 1000's they do not bleed off very fast and can take several hours. Its best to discharge all the caps with a 20 ohm(10K is too high and will take too long to discharge the circuit) 10 watt wire wound resistor before you do anything. If in doubt just take the 20 ohm resistor with some clip leads and place it across the plus and minus lamp leads. This will also discharge anything thats stored in the start circuit. The reason its best to discharge this way is because the 1000 has a seperate higher voltage DC start circuit which is isolated from the lower voltage DC by the blocking diode. Shorting the lamp leads with the resistor discharges both DC circuits [thumbsup]

.

Another word of caution.... don't leave your meter or anything else but the bulb connected to the lamp leads and then try to start the lamp. The high voltage from the ignitor will ruin your meter in just a fraction of a second.

Mark

Posted by Larry Davis (Member # 609) on 09-05-2004, 10:24 PM:

Thanks, Michael and Mark for the advice. I will keep you posted about my progress. I have removed the power supply from my other lamphouse for practice. But the first thing I will test in the lamphouse I want to fix is the blocking diode. It looks like it is in the right spot for where I saw the flash.

Posted by Steve Kraus (Member # 476) on 09-05-2004, 11:50 PM:

What other self contained lamps have there been and how come no one (to my knowledge) has built a modern one? A lightweight switching supply might make a lot of sense in this situation. Some of the components might already exist for video projectors.

Posted by Mark Gulbrandsen (Member # 72) on 09-06-2004, 10:37 AM:

Check out the viseo threads at www.diyaudio.com and let us know if you find any good light sources the DIYers are using on their home made video projectors.....
Mark

Posted by Steve Kraus (Member # 476) on 09-06-2004, 05:52 PM:

No thank you; I'm not referring to a DIY effort. I mean a manufacturer packing a switching supply right inside a lamphouse. Like an ORC 1000 but lighter. I would imagine it would be somewhat larger too since a more efficent reflector would probably be bigger. Probably not bigger than a 1K or so. Or is there just no demand for something like that? The ORC 1000's still soldier on. Less than ideal for any sort of a permanent installation but just the ticket for portable work. I suppose with quick connectors a two piece arrangement works as well.