Christie CP2220 Integrated Motor Control Board stepper driver fried

[Christian Hove]

In one of our CP2220s a stepper driver on the integrated motor control board for the steppers moving the lamp in the mirror has let the magic smoke out.
The consequence is that the X-axis stepper is not moving (just braking) and attempting to do an automatic alignment (LampLOC) of the lamp generates an error - Y, Z and the dowser still works.
It has been this way for some time and I've managed by disconnecting the X stepper to turn the motor by hand in order to align the lamp.
Now before just replacing the board I would like to make sure (or at least probable) that it is not something external to the board that has caused the driver to fail.

I have measured the same resistance of the windings as for one of the other (working) axes and I have tested the stepper motor by connecting it to one of the other drivers where it seems to work correctly.

Is there some easy way to test the limit switch without throwing alignment off? (maybe somewhere in the service/status menu the state can be read?)

Thanks,

Christian

[Dave Macaulay]

I've had the same error (or maybe one of the other motors) and replacing that board solved the failure to complete lamp-loc.

[Steve Guttag]

I've found that the later boards are better, in general to the earlier ones. Note too, the lens board and the lamp board are identical so you can pick which is more important to you if you are down on one.

[Marcel Birgelen]

Those motor driver ICs can get very hot. Every time I used them myself, I fitted them with a cheap, passive cooling element, which greatly reduced the surface temperature, even if the duty cycle of the motor(s) to be driven was relatively short. I'm not sure why they saved on a few cents of metal here.

[John Thomas]

Start by reseating the connections on the board, if you haven't already.

Extremely likely that it's the the board. I have replaced a number of those boards, and never a stepper motor.

If you want to be 100% sure, just swap the X and Y connections at the board. If you can now move the X using the Y control from the TPC, the problem is the board. If the X still can't move, the problem is after the board.

Edit: Looked more closely at your photo. Yeah it's the board.

[Randy Stankey]

It's hard to tell just from looking at a picture but, from what I can see, that board should not have passed inspection.

I see cold solder joints. There are components that have gone off the pads. There are sloppy fillets on the gull wing leads on the chips. I can't tell for sure but it looks like there might also be flux residue all over the board.

Some of these problems might have occurred as a result of the failure but others certainly did not.

Take a look at the component marked "C58". It is standing up on its edge. It's supposed to be lying flat. Furthermore, it's not even on the pad. The only thing holding it onto the pad is the solder...and that is a bad solder joint.

That board never should have made it off the assembly line. That component, C58, is such a glaring failure that it, alone, would have caused the board to be rejected. You can see it with your naked eye!

If that board passed automated inspection at the assembly line, then passed visual inspection before it was sent to the next phase of assembly and THEN passed final QA Inspection with such major mistakes as I can see just by looking at an average quality JPEG from the Internet, there is no telling what other hidden defects there might be.

That PCB is a wreck! It should never have made it out of the factory. Not even if it was IPC Class 1, which is the lowest class! It was bound to fail!

If I found that board inside one of the projectors that I was responsible for, I'd be on the phone demanding a new board be send out, immediately.

As a matter of fact, if somebody from Christie is reading this, they should just, plain send out a new board, free of charge.

I would have been written up if I let a board that bad get by me!

[Christian Hove]

I've found that the later boards are better, in general to the earlier ones. Note too, the lens board and the lamp board are identical so you can pick which is more important to you if you are down on one.

Yeah I noticed that on the CP2220 Interconnect drawing. In our case (a cinema screen with varying flat/scope content) the lens motors are by far the most critical :-)

[Christian Hove]

Those motor driver ICs can get very hot. Every time I used them myself, I fitted them with a cheap, passive cooling element, which greatly reduced the surface temperature, even if the duty cycle of the motor(s) to be driven was relatively short. I'm not sure why they saved on a few cents of metal here.

Yes - However as far as I can tell the stepper driver IC is actually just driving four MOSFETs. So I guess that the heat produced in the stepper IC is mainly caused by the gate capacitances in the MOSFETs.

[Christian Hove]

Thank you all for you comments, I will replace the board.