Film-Tech Forum ARCHIVE: Christie Platter Control Card is different

This is topic Christie Platter Control Card is different in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Danial Simmonds (Member # 4638) on 03-10-2008, 08:14 AM:

Hi guys hope everything is going on well,

I just installed about 10 new christie P-35's with their platter. But one of the platter cards happened to turn bad yesterday, I checked my stock but i couldnt find the exact same card so i was wondering if anyone knows if this picture of the new control card can be replaced with the older type control card that most of us have been using?

Posted by Mark Gulbrandsen (Member # 72) on 03-10-2008, 09:14 AM:

There are a number of different versions of the card... all made by Minark and they all more or less work the same. The only exception was the card that was based on the 555 timer IC... but all of those were supposedly taken back and exchanged.

Mark

Posted by Scott Christopher (Member # 834) on 03-11-2008, 05:49 AM:

I'm using the cards based on the 555 timer, and slowly replacing them with the card in your picture. I have had no problems with a direct changeover, as the inputs/outputs and supply voltage remain the same.

Posted by Danial Simmonds (Member # 4638) on 03-11-2008, 07:41 AM:

Hey Thanks for your reply Mark and Scott,
However i did try to put in the card with a 555 timer, what happened was the fuse kept on blowing then the card fried.

Im waiting for the card as like in the picture to be sent to me from christie, it is a new platter and it originally used the new card. Once i recieve the replacement ill try it if it blows also then im gonna have a lot of work to do checking all the wires...

Thanks for your info guys, It helped me a lot.

Posted by Mark Gulbrandsen (Member # 72) on 03-11-2008, 08:56 AM:

You guys will note that the 555 cards are very unstable... There is alot of temperature drift causing alot of speed drift... just try to keep one set where you need it!! I'm amazed that there are any of these boards out there anymore... they were only made for a very short time.

Mark

Posted by Scott Christopher (Member # 834) on 03-12-2008, 08:43 AM:

I'm slowly pulling out those 555 timer cards - yes the are very unreliable especially with the 5watt resistor solder pads.

In regards to the card not working, make sure the motor hasn't got a short circuit. If the carbon dust isn't blown out often, you'll get a short from earth to pos or neg. I've had this happen where the fuse blows but the motor spins up at full revs. Very nasty outcome. If they're new, i highly doubt this would be the problem.

Also check your supply voltage. We use a step down transformer from 240v to 115v AC @ 5amps.

I recommend you check everything before possibly killing another card.

Posted by Scott Norwood (Member # 30) on 03-12-2008, 09:38 AM:

We had a bunch of the "C" series cards go bad at one theatre that opened in 1998 with all "C" cards. Almost all have been replaced now. The failure mode is that the platter deck would just stop spinning mid-show.

What is the component that goes bad and how expensive is it? I still have a bunch of the bad cards and would like to repair them if it is time- and cost-effective to do so.

This theatre also got the bad batch of rubber drive pucks that turn to goo. All of those have been replaced and both the black (Wolk?) pucks and the white (Christie?) pucks seem to be holding up well.

Posted by Scott Christopher (Member # 834) on 03-15-2008, 01:22 AM:

Check the 5K - 5watt resistor soldering. These resistors get hot and the solder joint dries. This was my main problem with these cards (PN347C). I've also had bad soldering on one of the surface mount resistors (the 470ohm from memory). This one is the second surface mount device away from the 5watt resistor. If it's the problem, you should notice a slight gap between one edge of the resistor (smd) and the board.

Regarding the resistor, I've thought about mounting a 10watt instead of a 5watt to the platter column and running leads to the board (through a connector) - I haven't done this yet, but would be interested to see if it works.

Posted by Mark Gulbrandsen (Member # 72) on 03-16-2008, 07:47 AM:

Scott,

On the present version of that card the 5 watt resistor has been eliminated... its just going to happen over and over... you could try soldering that back on with silver bearing solder which has a much higher melting point than regular solder but then they got rid of the problem for good reasons.

Mark

Posted by Scott Christopher (Member # 834) on 03-17-2008, 03:42 AM:

I agree, I only repair the cards for emergency spares if needed.