Film-Tech Forum ARCHIVE: Christie Preamp board and Basement Headaches

This is topic Christie Preamp board and Basement Headaches in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Tim Reed (Member # 137) on 12-15-2007, 04:27 PM:

Hey, what's up with this, Christie fans? Case file: P35GP.

Using the part number in the Christie book, I ordered a replacement preamp board (seen below, mounted to the projector frame), which is connected to the actual reader via a cable. I received, instead, a board that looks to be designed to fit on the back of a "normal" reader, and has the lens attached to the board.

Is this an older design of Mark G's favorite projector in the world? Am I supposed to unsolder the lens from the new board to make it work with this configuration, or is there another part number for the proper board? Or, will the new board and lens somehow attach to the reader in a way I can't yet figure out?

Unbelieveably, I'm also having trouble getting Dolby Digital to work consistently on this projector. I can see a good deal of unsteadiness on the scope, but otherwise have my voltage level, goal post position, and focus... although I'm getting 5,F,5,F,5,F's on the DA-20. Suggestions, please, on most-likely bearings to replace or items to zero-in on? Thanks!

Posted by Tim Reed (Member # 137) on 12-16-2007, 05:58 PM:

I would've expected Mark Gulbrandsen to jump in on this by now? I guess it mustn't be the greatest projector after all, as I surmised... [Confused]

Posted by Mark Gulbrandsen (Member # 72) on 12-16-2007, 06:28 PM:

Jumpin in Timster... [uhoh]

I've replaced that board a couple of times over the years and yes, it "used to" come with the solor cell (not lens)attached to the end of the cable. You can unsolder the old board if ya want to but I have also seen a couple of cell failures in older Kelmar units so I always replace it as a complete unit with a BACP RSTR. This is what you SHOULD also be doing too. Aside from the nifty audio presence lights the customer then has a user replacable LED head and preamp board and much faster optics with longer lifespan LED... the RSTR's are not very expensive. Those original Christie readers were made by Kelmar Systems, the cell and board came from Dolby... they are excellent units as they afford 100% adjustment of the pickup by the user but the optics are sllllloooooowwwww. Still I prefer the RSTR units as they afford the Customer the ability to repair his own unit... And Sam's a really nice guy!

Everyone knows that the P-35's basement readers never tracked very well. Its because of the double sided timming belt and the flutter it introduces into the film motion... lightly squeeze the two dancer arms together with film running and you can feel it! The Christie basement reader was such a dismal failure(like the original Simplex 5 star) that Christie took most of them back and credited the larger chains for them. They were generally replaced by Cat 701's at the time. There is a 1 hour fix for it that is really inexpensive and allows tracking down to typical 1 to 3 error rate zone... but I'll let you figure that out on your own [thumbsup]

.

P.S. Along with the fix be sure all the ball bearings are good while you're in there. And check the dual lateral guide roller ruby slippers to be sure all's well in there(you need the factory gauge to be able to set em up properly). A properly running P-35 is a VERY quiet machine.

Mark

Posted by Steve Guttag (Member # 268) on 12-17-2007, 02:57 AM:

As usual...the solution to this machine is to keep throwing money at it...after all they keep coming up with fixes. Mark's suggestion in this situation is to use a BACP reader...yet this is obviously a basement digital reader too so that isn't an easy option either...unless you have an exhibitor that wants to throw yet MORE money at this machine to either replace the drive train with the latest upgrade or to throw away the digital basement reader in favor of a penthouse and leave the fluttery drive train for the analog.

Posted by Tim Reed (Member # 137) on 12-17-2007, 05:59 AM:

Thanks!

This is a contract customer, however, where we have to supply parts. So I should have to make this new board work somehow, or get the proper replacement part. Is the cable just an extension of the cell, does it match pin to pin?

Posted by Mark Gulbrandsen (Member # 72) on 12-17-2007, 08:05 AM:

Tim,

Replacing the whole thing aside are you sure which is bad... the board or the cell? You could replace just the board alot easier than replacing board and cell. If you need to do both... Carefully unsolder the cell from the new board... don't overheat the thing doing so... then do the same with the old cable and cell and re-use the old cable or just use a hunk of 8451 or similar. You will also need some heat shrink for about 20 ga wire to insulate the conductors on the cable where you re-solder it to the new cell. Its the sort of job that'll test your soldering skills! Should not take more than an hour though. Aligning the new cell in the back of the scanner is the tricky part and be sure to keep lead orientation the same so you keep left and right in the proper positions. You'll also have to get the cell azimuth very close on... remember the slit is on the cell itself!

The flutter upgrade is essentially the new pulley drive kit... It's a very inexpensive kit... around 200.00 and it includes ALL new round tooth pulleys and ALL new belts in the entire projector. So contrary to what Steve thinks the whole pulley kit actually costs considerably less money than replacing the two alumnium pulleys on a Simplex 5 star. The first pulley kit change out took me about an hour but if you have bad shutter driver or jackshaft bearings it'll take you longer. Only use bearings in there with rubber seals on them, shielded bearings don't last very long as the grease dries up too fast!! You need a no. 1 arbor press and at least a good assortment of sockets to seat the bearings correctly. The other nice aspect of the pulley kit is that the plastic pulleys have a lubricant imbeded in them and the round tooth belts do not shed all the black crap all over the inside of the projector. Expect a 5 year plus belt life minimum. Christie also has a plastic curved runner available which is more or less the same as the material that the FP-20 skate is made from, its also very inexpensive, about 15 bucks.

Mark

Posted by Gordon McLeod (Member # 33) on 12-17-2007, 08:09 AM:

I have had cell failures on almost everyones units except so far BACP
I know centronix made the unit for dolby but I think it was solely for them and I don't know any other source

Posted by Mark Gulbrandsen (Member # 72) on 12-17-2007, 08:15 AM:

There is another source somewhere as the Austrailians are making their own reverse scanners.

Mark

Posted by Steve Guttag (Member # 268) on 12-17-2007, 09:05 AM:

I don't know how you priced out your Simplex pulleys but I'll sell the pair for under $200 to anyone. Then again, how many of you out there need to change your Simplex pulleys?

For Christie, this is not exactly their first drive kit change and despite Mark's optimistic view of the upgrade, they are unproven long-term.

Back on Topic...the reader in your photo sure looks like a Kelmar and as such, I would order the board from them. It is likely to be just a parts swap at that point and only a new A-Chain would be in order. In any event, I would give Tom at Kelmar a call.

Steve

Posted by Mark Gulbrandsen (Member # 72) on 12-17-2007, 07:55 PM:

Actually the Christie pulley kit was in field testing for several years before it was released.

I just got done changing 9 sets of 5-sar pulleys that were but 6 years old... belts and bearings and idlers as well, most of it ... especially the idlere were shot. Every other tech I have known over the years also has done more than his share of them!! The motoR pulleys always wear THE worst but the large main pulley always gets a nice edge cut into the teeth when it wears so you're guaranteed to chew up a new belt in a short time. Cleaning the black crap off the back is also time consumming but ya have to do the job right! On the 5 Stars everything wears out SOONER THAN LATER. The projector is barely just a little better than the sound head.

On the Christie scanner... they were custom made by Kelmar for Christie for a short while and then Christie made them on theor own.. Kind of a sore spot with Tom. Christie made up the boards with the cell at the end of the lead themselves... surely the Timster can solder a short length of wire onto a cell and then to the board... thats pretty basic.

Mark

Posted by Steve Guttag (Member # 268) on 12-17-2007, 08:28 PM:

Maybe things wear a bit differently out in Utah and such...we really don't have any significant 5-star pulley wear. The only pulley that tends to die is the tension idler that has those dinky R4 bearings (P-3368)...use of better grade bearings will go a long way. If one has the round-tooth pulley/belt set, then those hardly ever have problems...or at least WE hardly ever have any problems.

Steve

Posted by Mark Gulbrandsen (Member # 72) on 12-17-2007, 09:20 PM:

The ones I changed were at an AMC... standard grind house operation type of place. The pulleys were hammered!

Mark

Posted by Tim Reed (Member # 137) on 12-17-2007, 11:07 PM:

Thanks, fellas. I farted around with this thing for a couple of hours today (a good deal of that time was spent trying to pull some semblance of Dolby Digital out of that machine, while the optical reader was removed).

Steve, yes, it looks like a Kelmar to me, too. I will give them a call tomorrow, as none of my calls to Christie today were returned.

Mark, I understand about the cell alignment, thanks. I had it ALL apart today! [Smile]

I began to suspect the cell as the source of the dead channel, too, as I was getting sporadic noise from that side while adjusting the optics.

I was going to solder/unsolder and move the new parts to the reader assembly, but the wires weren't coming out as easily as they should have - and knowing that the cell connections on the new board were even smaller, I thought: wait a minute... at LEAST I've got mono sound now. The solder points on the new board are mighty close to surface-mount components, and if I screw these up then I have nothing. No, I want the RIGHT PART, darn it! If this configuration is indeed discontinued, then that would make it obsolete and the customer would be responsible for buying an upgrade. If the proper parts ARE available, however, then that's what I should be using. I ain't stickin' my neck out.

FWIW, here's what I am dealing with:

This is the new board.

The cell on the new board...

The existing assemblies.

Old board... this is the side the cell is soldered to on the new one...

Thanks, again. Will update this when I come out the other side.

Posted by Mark Gulbrandsen (Member # 72) on 12-18-2007, 08:03 AM:

Tim,

Having changed out just the cell on these before I don't see any sticking out of the neck involved. Its not rocket science... just a VERY basic repair.

Posted by Phil Ranucci (Member # 3820) on 12-18-2007, 08:06 AM:

Sorry to hijack, but in regards to the Christie belt kit, I was told to order one to 'kickstart' them into actually shipping the kits. No idea on delivery, quoted ~$300.

Posted by Tim Reed (Member # 137) on 12-18-2007, 12:11 PM:

Heya, Mark! If all I had to do was replace the cell, I'd have no problem. But I'm not 100% sure that's the trouble. I'd have to solder onto the new board, too, which is somewhat tighter and brings SMDs really close to my iron.

Posted by Mark Gulbrandsen (Member # 72) on 12-18-2007, 06:54 PM:

Using 22 ga wire like 8451 Belden it shouldn't be very difficult. A short piece of Mogami wold also be a good choice because it's super flexible. I can guarantee you that that cell was soldered onto that board by hand... it couldn't travel through the wave solderer like that without being destroyed. You should replace both the board and the cell at the same time... they are relatively inexpensive parts... why rack up extra hours trying to figure out which is bad... that costs the customer more in the long run. That particuluar scanner mechanical assembly is the best one Kelmar made so why not fix it.

Almost all Techs have to learn to improvise at times and make do with whats available... it happens alot with stuff from Christie, Strong, Neumade, Big Sky, and all the other manufacturers out there... especially with Ballantyne parts lately. When manufacturers run out of a part for a certain era unit and they haven't sold one in a year they typically drop the part from inventory and do not make any more of them. So welcome to the club!

A Kelmar or C.E. Christie analog replacement scanner should also fit in there if you do decide to replace it. There probably isn't room for the BACP next to the digital scanner but then again ya never know. Never tried that one but Sam might know.

Mark

Posted by Mark Gulbrandsen (Member # 72) on 12-19-2007, 03:39 PM:

Tim,

The guys at Christie noticed this thread yesterday and wanted to contact you... but since there was no contact info for you they called me to get it noted in this thread. The correct part number you need for the job is "194909-001 Cell and board assembly". If you have any further questions regarding this part or the correct repair procedures please contact Jim Graton at Christie Technical Suppport at 714-503-3381.

Mark

Posted by Tim Reed (Member # 137) on 12-19-2007, 06:12 PM:

Thanks, Mark. Yes, I got a very nice reply phone call today from Jim Graton, complete with the correct part number. They call it: preamp and solar cell w/gray cable

THANKS AGAIN, EVERYONE!

Now, I can get that other board returned for credit. Glad I didn't go soldering on it before finding out! [thumbsup]

Posted by Monte L Fullmer (Member # 2797) on 12-19-2007, 11:18 PM:

Jimmy's real good with Christie - helped a lot with questions and support when I was with EDW's in my maintaining Christie units.