Would anyone possibly have a schematic or info on an Irem NX-30DM recifier? I cant find online and Irem dont have anything. I want to change out out the diodes and caps.
Thank you
Thank you
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My first question is why do you want to change them? Unless you are having extremely hard starting lamps or extreme flicker, they really aren't that big of a "wear" item. And even buying them as I suggest in my comments below, they won't be cheap.
You don't need the schematic for such a relatively simple task. Unless the diodes or caps are severely damaged or exploded, all the information you'll need is on the parts.
For the diodes, there will be a part number (something like IR 640 or whatever) and a diode symbol stamped that shows the direction (polarity). You will have "forward" and "reverse" sets, each on their own heatsink. It is very important to NOT mix them up (or put them on the wrong heatsink) or you will release the magic smoke that is inside them. When you get the new parts and change them do them ONE AT A TIME, matching the direction of the diode symbol as you do so. You must also clean the old (usually white) heatsink compound off and apply fresh compound. DO NOT waste your money getting diodes from a cinema dealer, the markup is usually ridiculous. Any online electronics seller (Mouser or Digi-Key) will have either exact replacements or a good cross referenced part.
As for the capacitors, there are two values: the voltage rating (You match that, or go higher, NEVER lower) and the capacitance in microfarads (usually something like 10,000uf with the uf meaning microfarads. You can go about 10% below or 20% over the capacitance without causing serious issues (under might increase flicker or make the lamp hard to strike, over by 20% or less will do no harm.)
Also: rectifiers have high voltage, high current present. Turn it off, disconnect it from power, and wait at least 30 minutes before touching anything inside, Also, before handling the capacitors, short them out first (Best to do that with a 3,000 or more ohm 5 watt resistor, leaving it connected for a minimum of ten minutes.) If you have an old screwdriver you don't care about you can bridge the terminals of the cap with it, beware it may make a very loud spark. I don't recommend that method as it can damage the cap (not a concern if you are going to replace it anyways) or if you are accidentally touching the metal part of the screwdriver it will shock you. There have been emergency calls where I had to get them back on screen quickly and changed diodes and/or caps, and in my haste I forgot to discharge the caps and had a few unpleasant surprises.
With a bit of patience and taking your time and precautions, it is a task you can do. Just remember the energy you will be playing with. -
Thank you Tony. The capacitors, to me, are not looking good. There is white corrosion on top of them. I think the diodes are good, but would like to have spares. For the age of the unit, It is in good shape. The bulb always strikes on first hit. I dont see any visible flicker in the light. The bulb does have a small amount of pitting. I dont think its heat venting, I have a 400 cfm fan. It is a 1600w bulb so I think that is enough. As for inward rush and ripple I do not know how to measure. I know the inward rush is a danger zone, so I may never figure that out.
So for AC ripple, is the amperage clamp on AC setting around the DC lamp supply lines a reliable method?Comment
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To my knowledge, unless extreme, most clamp meters are not going to have the resolution or sample/update rate to show you ripple. That kind of thing is easier to see on a suitable scope or power analyzer. The Strong supplies had a ripple warning light, I’m guessing the Irem doesn’t self report on that variable?
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Ryan, no self report. I dont even know how old this thing is. Irem themselves had no info or data on the rectifier!Comment
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IMHO, you are not seeing any problems on screen or in strike behavior that would make me want to "fix something that is not broken yet". The white stuff on your caps might be a bit of oxidation of the can itself, but no internal issues. If you are willing to drop big money on giant caps, maybe you are also feeling spendy enough to get a nice LSR/ESR meter before deciding they are bad?
This is a bit overkill if you don't have use for it all the time, but handy tool!
https://www.digikey.com/en/products/.../ESR70/9687220
There is certainly value in getting familiar with what parts you would need should you have to do any repairs in the future on these beasts. If they are hard to source ones picking up a few spares ahead might be wise.
Our two rectifiers currently take a couple hits to strike, they didn't when I put them back into service. We are just thankful we have functioning ones at all for the moment. I have a dead one on a bench waiting to get recapped and new fuses (and two others in line after it), caps tested as out of spec. If those come up good I'll pull the active ones and check their components too. I should probably check the diodes too but I haven't ordered any yet and am, perhaps wishfully, thinking caps alone is worth a shot first.Last edited by Ryan Gallagher; 10-24-2025, 08:37 AM.Comment
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Thanks Ryan. I always like to have parts ready to go if anything breaks. Even though this is not in a theater but in my basement, I hate when something breaks and It sits there broken. I guess I can test the caps. Thanks for the lead on the meter.Comment
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Note, there are cheaper ways to test caps, but all require de-soldering at least one leg. The benefit of an ESR meter is you can test them in circuit most of the time. The one I linked is the "pro" equivalent meter. There are cheaper ones too.
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What is/was the NX series? Was that part of their line of switching supplies, maybe the smaller ones? Bigger ones were EX I think. I remember some that sort of looked like overgrown car audio amplifiers, don't recall what models those were.Comment
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I will be curious to see the pics. I do remember running into an oddball switcher one time but I don't recall if it has an Irem label on it, it may have been Xetron which then could have been sourced by them from somewhere else.
If Irem built the switchers themselves I don't think they were designed specifically for cinema, possibly some other industry and adapted to cinema. It may have been a big buyer like Cinemeccanica in Europe and maybe Xetron in the US were asking for a switcher option so they went and sourced something and packaged it for cinema (bolt in place of a G series?) to give them that option. Not sure who was asking for switchers but ya never know how the big circuits think.
At least here in the US the N series was the long running freestanding model with the 'steering wheel' on the top. The G series was basically the same guts just with no case and laid down in the bottom of a console. As long as the were N3 or G3 (3 phase power) they were pretty simple, 6 reverse diodes on a single plate, couple decent sized caps, little relay board, and a contactor. Not much to them or to go wrong not even a fan to get dirty or quit in many cases. Single phase added a few parts and there were some kinda oddball models there.Comment
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Tj, here are some pics IMG_20251024_151428.jpg IMG_20251024_151448.jpg IMG_20251024_151925.jpg IMG_20251024_151901.jpgComment
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I was gonna say internally it looks like a N1X50 so I was gonna look that up to see if the innards maybe matched and the manual also has a N1X30DM and that looks like it just for some reason that one was from before the did the N1 and N3 designations? Anyway looks like both a schematic and parts list right here in the warehouse.
https://www.film-tech.com/warehouse/...XETRONN1N3.pdf
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Thank you TjComment
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