Resolved AOX not working with filter wheel

Hi,

I have a 16803, 7 position wheel, off axis guider and the AOX. All had been working perfectly. Recently the filter wheel stopped turning. Bill diagnosed a bad circuit board and replaced it. All components tested fine on his test bench. At the observatory, the AOX refused to move. This was observed in TSX, maxim and ccdops.

However, when I unplugged the filter wheel from the AOX, the AO works perfectly. On all three software packages. The filter wheel works regardless of the AO status.

This may be relevent, or just a tangent. Originally I used the SB power cables. I found that running the camera, cooler, filter wheel, guider and AO cuased errors. Another thread expressed the opinion that the through the mount SB cabling is too narrow a gauge to support the electric load. Sure enough, that problem was eliminated by using SBIG supplied power from the wall to the camera.

I have only one thought, other than to see if Bill can diagnose something else. My guess is that the power supply might be going bad, causing the AO to fail to move.

Any thoughts from the group? Bill suggested I ask.

Thank you,

Mike

 

Hi Colin,

Cabling goes like this. Camera I2C aux to AO I2C in,
Filter wheel is hardwired to AO I2C out.
Guider is plugged into camera remote guide head.

 

The camera I2C aux is male. The I2C cable has a male and female end. By plugging the female into the male camera port leaves me a male I2C end. The I2C port on the wheel is male. I would need a gender changer to plug that in. The filter wheel RS232 port is female so I could plug into there.

The white cable hardwired to the filter wheel is a serial female p,lug. So it can only go into the AO I2C out, or into the camera I2C aux.

If it's easier, I can send photos, but I'm guessing you know what all this stuff looks like! Or I can talk it out.

Thanks,

Mike

 

Hi Doug,

Since the AO works when the filter wheel is excluded, would that suggest a bad filter wheel cable?

Also, if they are all in parallel, why would a bad filter wheel cable cause the AO to fail?

 

Good points. I'll check those out.

 

Case solved. At Colin's suggestion I removed the power cable from the thru-the-mount path and ran it externally. Works like a champ. Thanks for all the help!

Mike