Lamp un-strikes (Strong Super 80)

[Ryan Gallagher]

a couple of questions for you, Ryan
1) what model of Strong switcher are you using? i know you said R series but what is the full Strong product number from the data plate on the side of the unit?
2) you read 125 vac on the three legs but what are you reading across the legs? A-B...A-C...B-C Are you reading this at the terminal block just inside the rectifier?
3) have you checked the three-phase breaker in your main breaker panel? years ago I once worked several hours on an IREM high-reactance rectifier to no avail only to go over to turn on power to it one more time and then hear the breaker itself start crackling. one of the connections at the breaker was hanging on by a thread, just enough to register 125/leg at the rectifier but not enough when any load was applied.

I'll get those product numbers for the thread tomorrow.

I had that thought too after I left work, re the mains breakers. I'll meter across the legs tomorrow... I was metering mains in the Hubble before the power supply (no load). Because this one has a MS connector harder to meter while loaded unless I crack it open, which we have not done yet. I might be able to meter that at the panel with a load.

I may also have a 3phase tap with hubbel tail not in use on that panel. I suppose I could run an extension and bypass the current breakers in use too.

[Ryan Gallagher]

As requested Rectifier Models:

Installed non-working (The one at issue):
6280110R 4-7K with MS+Hubbell connect

Installed working in 2nd projector:
6280112 4-5K with terminal blocks

Bulk spares that shut off on strike (possibly mis-configured internal switches?)
6280107 4-5K with MS+Hubbell
6280110R 4-7K with MS+Hubbell
6280107R 4-5K with MS+Hubbell

An older previous Pull not re-tested yet (partner to the working one):
6280112 4-5K with terminal blocks

[Ryan Gallagher]

a couple of questions for you, Ryan
1) what model of Strong switcher are you using? i know you said R series but what is the full Strong product number from the data plate on the side of the unit?
2) you read 125 vac on the three legs but what are you reading across the legs? A-B...A-C...B-C Are you reading this at the terminal block just inside the rectifier?
3) have you checked the three-phase breaker in your main breaker panel? years ago I once worked several hours on an IREM high-reactance rectifier to no avail only to go over to turn on power to it one more time and then hear the breaker itself start crackling. one of the connections at the breaker was hanging on by a thread, just enough to register 125/leg at the rectifier but not enough when any load was applied.

What is the proper way to meter the no-load voltages on these MS connector units? Just meter across the unstruck lamp? (EDIT: LOL Stupid Question, NO) Meter the high voltage pins without the lamphouse attached? (EDIT: Better Question)

Going compare that value to our working one today.

3phase before loaded metered 216vac across each leg. Going to meter it loaded at the hubbell terminals today also.

I opened one of the spares with the power-off behavior and the internal switches were all at default. Gonna try one again and adjust current trim higher, maybe it was just responding properly and powering off on a no-strike/open circuit result.

And if none of that gets us anywhere, we may bite the bullet and move the working switcher over to this projector, only way to know for sure the issue is not in the lamphouse it seems.

[Ryan Gallagher]

3phase leg to leg appeared to be stable at 213vac when loaded with the lamp on, even while issues exhibited.

All 3 of my unproven spares were retested with a dip-switch configuration that matched the semi-working one (all defaults).

They all 3 still powered up with "xenon on" already lit, and powered down when you requested lamp on, and would re-power and click if you left the on switch flipped, but no error lights. Same behavior at all current trim positions, although as you turned current trim up you could sometimes hear an audible high frequency whine.

Unlike the working one, they are the variety without the spot/console switch. Are those intended for manual/spot operation, or were they marketed as console only units? My hunch is manual/spot units, but maybe their pinout on the MS connector differs from ones that have the switch? That or they developed their own issues in the 10 years of storage. (But to be fair, they were tested in 2017 and exhibited the same behavior).

I only continue down this spares rabbit hole because I have not yet been given permission to move the one working supply over to finally confirm lamphouse vs supply issue.

[Ryan Gallagher]

For those following along at home, on my supplies that power off at lamp on request, ones that happen to lack the "spot/console" switch.

I think I found my missing manual page on a completely different model's manual. The MS pinout needs to be changed for "spot" operation on the these Type 6280107 and 6280110 units!!!

Will find out next maintenance opportunity. Many thanks to an email conversation with Brad that hinted there might be more information about MS Pinouts missing from any given manual (the specific unit manualsI had been referencing had no MS diagram).

Appendix A from the 620014 and 620015 manual:
http://www.film-tech.com/warehouse/manuals/STR6200014.pdf

Appendix-A.png

[Ryan Gallagher]

Halle-fuckin-lujah!!!

LetThereBeLight.jpg

Re-wire of the MilSpec connector on supply for "manual/spotlight" operation according to that appendix above did the trick for the 1st of 3 spares.

Gonna do a burn in and watch it for the rest of this David Byrne cover band. Good celebration music!!

[Mark Gulbrandsen]

Bravo on figuring that out!! In the late 90's and early 2000's I used to service and install new Strong spotlights. The only difference between those and film projector lamphouses were that the lamp was mounted in reverse of the cinema lamp house, as odd as that seems. Hence the dc wiring was different. But that was the only difference. I've actually subed in a cinema rectifier for a spotlight rectifier a number of times. The follow spots and rectifiers are still being made. Not sure if Strong still owns that division or not, but they are still made in Nebraska.

[Ryan Gallagher]

Bravo on figuring that out!! In the late 90's and early 2000's I used to service and install new Strong spotlights. The only difference between those and film projector lamphouses were that the lamp was mounted in reverse of the cinema lamp house, as odd as that seems. Hence the dc wiring was different. But that was the only difference. I've actually subed in a cinema rectifier for a spotlight rectifier a number of times. The follow spots and rectifiers are still being made. Not sure if Strong still owns that division or not, but they are still made in Nebraska.

Thankfully i did not have to reverse the heavy guage DC solder. It was just lose one tiny jumper and move another cable between the small cups. DC connections were very much in the way, but with a steady hand it was managable.

If i was doing it to be easily reversed i would put some wagu terminals on the appropriate leads, but we’ll never be an automation house for 35mm, so just resoldered em. I guess if we ever went to a different lamphouse we might have to reverse the change.

These spares were 2nd hand to our booth in 2014, they tried them in 2017 and gave up. Making them work was long overdue!

We still have two super troopers, one of them has a much more modern strong switching suppy, blue chassis. But ours are no where near 4k rated to function as alternates for the projectors.

[Mark Gulbrandsen]

The 3 - 4k model is the Gladiator.

[Randy Stankey]

Thankfully i did not have to reverse the heavy guage DC solder. It was just lose one tiny jumper and move another cable between the small cups. DC connections were very much in the way, but with a steady hand it was managable.

Those circular connectors are one of the things I make at work. (The cable harnesses, not the connectors, themselves.) I can't say exactly what they are for but, if you know what the phrase "Electric Boat" means, you'll know, pretty much, what I have been doing, lately, at work. That contract is up so they will, soon, be moving me to a line that makes product for the "Skunk Works." In the interim, I've been working on Micro-D, boardmount connectors. Many of them are plated with yellow chromate that is so fragile that you can scratch it off with your fingernail if you aren't careful. Again, one wrong move and you can scrap a part. One time, the floor supervisor dropped a whole tray of them on the floor and we had to scrap and rebuild the whole order of 100 parts!

Anyhow, the circular connectors that I use have a different pattern but they are essentially the same thing only mine have built-in silicone, interfacial seals and the metal connector body is anodized OD-green. You look through a 10-power binocular microscope and you have to use a special insertion tool to poke the pins/sockets through holes in the silicone seals. If you get one wrong, it's a real PITA to get them out, again! If you make even the smallest tear in the silicone, the whole part is scrap and has to be rebuilt from scratch!

By the time we get through a whole order of cables, your eyes are so bleary from looking through the scope you can hardly see and your hands are so cramped that you can barely pick up a pen to sign your employee number on the work order.

My only suggestion is that, if you are soldering to gold plated terminals, you should double tin the cups, first and use Solder Wick to remove all the solder before you solder in the final connection. The layer of gold plating is usually only 50 to 100 micro-inches thin. The heat of your soldering iron should be enough to melt the gold and cause it to diffuse into the solder where it can be removed with Solder Wick or a solder sucker.

If you don't remove the gold, it will cause "Purple Plague" when gold mixes with the tin-based solder. It forms a brittle, intermetallic layer that can cause microscopic fractures in the solder joint. Double tinning removes enough of the gold to prevent plague.

If your terminals aren't gold plated you don't need to double tin but you should till pre-tin and clean with iso-alcohol before and after you make the joint. Make sure you remove all of the oxidation and flux residue because it can cause failures, down the line.

I understand the difference between the high-spec, military stuff that I make and the "ordinary" stuff we work with in theaters but, given the fact that film gear is becoming as rare as hen's teeth, it's worthwhile to do things as well as we know how because the repairs we make are going to have to last for another ten or twenty years with little to no hope of obtaining replacements if they fail, prematurely. As they say, "Pay me now or pay me later."

I'm glad you got 'er done! I know what it's like. Bravo!

[Ryan Gallagher]

If you don't remove the gold, it will cause "Purple Plague" when gold mixes with the tin-based solder. It forms a brittle, intermetallic layer that can cause microscopic fractures in the solder joint. Double tinning removes enough of the gold to prevent plague.

If your terminals aren't gold plated you don't need to double tin but you should till pre-tin and clean with iso-alcohol before and after you make the joint. Make sure you remove all of the oxidation and flux residue because it can cause failures, down the line.

Not gold plated, nothing as small as the stuff you deal with! Cleaning up flux is always a good idea. I was still in testing mode. I might give them another pass and decide if I should put the snap terminals in there for the next guy or not.

[Randy Stankey]

If terminals were soldered when they came from the original manufacturer it's best to solder when you make repairs or modifications.
I don't know how many times I've received parts for rework where I took one look and said, "What IDIOT did that?!" It's even funnier when you look at the original work order and you find out that YOU're the idiot!

Last night, I potted-in two 100-piece orders of these connectors:

Micro-D.png


They are about an inch long and less than a half inch wide. Some schmuck like me has to sit there and poke all those wires into all those holes by hand. The plastic backshell has to be installed by hand. The hardware has to be torqued with a calibrated torque driver. Then you use a hypodermic needle (blunt tip) to squirt epoxy in to fill the whole part. One fuck up and it's rework time! If the part can't be reworked it has to be scrapped and rebuilt from scratch.

We tell our new trainees that it's better to make one good part than to make ten bad ones. It's better to take an hour to make one versus scrapping a whole order.

If I fuck up, we can requisition new components. If you fuck up, you could be out of business until you can find replacements... IF you can find a replacement!

I'm not saying you should do mil-spec work but you should do as well as you know how so that you are less likely to end up in the same situation you are in, later on, when replacements are even more difficult to find than they are, now.

Consider: It was somebody who came before you who did something that wasn't quite right (knowingly or unknowingly) that caused the problem which put you in the position you are in, today.

It really sucks to open up the back of a projector, take one look inside and say, "What IDIOT... !"

[Ryan Gallagher]

Converted the other two console spares to spot mode wiring today. We’ve gone from zero working spares to TWO!

Bonus is now I have good ones not in use to serve as a reference to try to further diagnose our two bad ones. Low hanging fruit but will try swapping control boards one day, narrow it down perhaps.