Fujimoto Paper Sensor Errors

I am running a Fujimoto CP51. It has a paper sensor as all RT processors do that lights up when paper is inserted. I'm getting some false positives with it. I've tried spraying contact cleaning into the male and female components but the problems persist. It's not catastrophic and it does for sure know when actual paper is being fed. My concern is that it may be replenishing incorrectly and running the dryer too much.

If you're familiar with the CP51, a yellow light comes on to indicate "paper". What I see most often in the false positives is a dimmer than normal version of the yellow light coming on. When I insert actual paper I get the full LED brightness of the indicator.

Would love to know your thoughts!

Is there a damaged wire that's leaking current some how?

Do you know what sort of sensor triggers the light? For example, is it a micro-switch or perhaps a photo-electric sensor? I'm guessing some sort of reed switch/micro-switch. There may be an adjustment that can move the switch a little closer to the paper (or where the paper would be) so that it's not partially closed or open which might account for the dimness of the indicator light. If there is no adjustment, it might be due to the switch being dirty internally.

bdial said:

Do you know what sort of sensor triggers the light? For example, is it a micro-switch or perhaps a photo-electric sensor? I'm guessing some sort of reed switch/micro-switch. There may be an adjustment that can move the switch a little closer to the paper (or where the paper would be) so that it's not partially closed or open which might account for the dimness of the indicator light. If there is no adjustment, it might be due to the switch being dirty internally.

Click to expand...

Way back I used an analytical balance, used a lot in a lab. Had an ordinary Microswitch, illuminated a scale, when worn or dirty light would be dim or flicker. It was a simple replacement. Not sure if this helps op but trying to clean switch might help. It may be something that was a commercial part, might still be found on Ebay.

I had the same problem with my CP-51 years ago and ordered a new strip from Fujimoto. I assume that it would be impossible to order one now. Spare parts for these machines are probably pretty scarce now I would think. When I used this machine in my darkroom I had two. The older one I used for parts.

My understanding is that this machine used IR sensors to detect the paper and activate the replenisher pump.
You could try a Q tip/cotton bud dipped in methylated spirits/denatured alcohol and clean the sensors (gently).

In case you don't have the manual, have a look here. It might help.

https://www.manualslib.com/manual/1616016/Fujimoto-Cp51.html