Jobo CPE2 motor only rotating clockwise

[uam225]

After a few initial hiccups, largely due to my hastiness and impatience, my recently bought CPE2 had been working brilliantly. But during the last session the motor suddenly stoped going anticlockwise or "backwards", halfway through the session. I only noticed towards the end of developer cycle, around 8min mark, but it might have happened earlier. The negatives came out fine this time with slight burn on the edges (HP5+, 120mm, XT-3), although this has happened before too so can't say whether the constant agitation in one direction was definitely the cause.

A few planned and unplanned changes for this session:
- I had been using the minimum amount of chemicals required (240ml) for both C41 and B&W but this time ended up using 260ml due to an odd amount of developer stock left.
- Thought I had not been adding enough water as only a small portion of the tank was ever in contact with the water. This time added more to a little over 1/3 of the tank was submerged in water the whole time. I understand it's not critical for b&w but thought why not, if nothing else, I can be more confident that the temperature is consistent throughout all sessions.
- After attaching the tank and starting the motor, just before pouring the pre-soak water, I realised I hadn't prepared the rinse aid. So left it running while I prepared that, leaving the motor running for about 5min with just the tank and reel.

Model: JOBO CPE2 with lift (not plus)
Tank: JOBO 1520 with 1505 cog/lid
Motor running time at (noticed) point of failure: ~15min
Motor speed: 2

I'm hoping to find out:
- What the cause and solution might be? Too much water in the tub resulting in somehow water getting into the electronics? Since then I've found out that the 240ml is not just the minimum but the recommended amount, with just 20ml more I couldn't have "over-loaded" the motor, could I?
- Can/should I just continue to use it like this for b&w? Seeing mixed views on whether constant one-direction agitation would be an issue for b&w film development. If not the negatives, will I be damaging the motor?

I'm aware there is an old thread discussing this but it seems dead now. I'm not experienced with electronics but might give it a go if it's low-risk.

Long time lurker, first time poster. Newbie to processing and darkroom as well as the forum, so pardon me if there is too much/too little info.

Thanks

 

[ic-racer]

See that the white arms of the reverse switch are engaging with the spinning spur gear assembly; flipping the switch up and down.

 

[mpirie]

Sometimes the white switch (crows foot) can be rotated out of the way of the gear leading to a single direction of rotation.

If the crows foot is in the correct orientation and is moving back and forth but not changing direction of the tank rotation, then there could be a problem with the wiring to the direction change switch.

Mike

 

[koraks]

What @ic-racer and @mpirie say above. I've had the same happen on my Jobo once. It was an easy fix; I just turned back the crow foot switch and everything went back to normal again.

 

[uam225]

Thanks everyone for the responses. It was the switch. I pushed it using a chopstick and seems to be running fine now.

Any thoughts on how to avoid this from happening again? Did I do something to cause this or is it just "one of those things"?

 

[koraks]

Does the tank wobble or is it not perfectly level with the machine? If the drive rod is bent or the motor mounts are loose, this can happen. I vaguely recall it was something along these lines with my machine. I don't recall it was a difficult fix and it has never happened again since.

 

[grahamp]

The CPE has a maximum tank capacity of 600ml. Your 240ml suggests you are using a 1520 tank. You could add a 1530 extension and still be under the machine limit.

The water bath level should be below the drive shaft. I usually aim to have the level just cover the lower portion of the red bottle rack with the tank in place. I do not do colour processing, so I do not have a large difference between the water batch and air temperatures.