# Melitta Solo E950 Bean Sensor



## ward1e (Jul 6, 2017)

I have recently purchased a second hand Melitta Solo it has been working fine for the past 1 month but as of yesterday the bean indicator keeps flashing and it is refusing to grind beans and or make coffee.

Looking at the documentation it appears this means that there are no beans present in the grinder. The problem is that there are actually beans in the grinder. I have tried emptying the beans out of the machine by turning it upside down and wiping down the grinder and refilling without any success.

Does anybody know how the bean sensor works on these machines (I'm assuming that is what is faulty)? Or does anybody have any experience fixing a similar issue?

Any ideas or advice would be much appreciated. I'm happy to take the screws out and look at the internals of the machine if required.


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## 4085 (Nov 23, 2012)

Visit this page and scroll down to the bottom and the Solo is listed. Download the manual for it as I have done and scroll to the back, faultfinding bit and it suggests a couple of things there for your symptoms

https://international.melitta.de/en/User-manual-529.html

Sorry, just read your post properly! @DavecUK.....can you help?


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## DavecUK (Aug 6, 2013)

I only tested the Varianza and the Barista TS. These are machines where you can't really easily take them apart and reassemble and at the time they were both loan machines. I now own my Varianza and won't take it apart to answer a forum question. I could never find the bean sensor, I always assumed it is an optical system, as there are instructions to keep the area clean. It works at night because I assume it to be infrared (optical). So it might have an emitter and a receiver sensor, somewhat like a TV remove control, but much smaller emitter/reciever..

In the Barista TS, there is a twin bean hopper and two little bumps inside each one which look like cowling's containing the emitter and receiver. Certainly they have little holes in them which cannot be for screws. The red dots show the presumed path of the beans. In the Barista TS, it knows which hopper needs refilling. I should really try and block the path and see, but it's fairly cleverly programmed, so it may retain bean low data and I would suspect it only lights up the emitter (infra red so you can't see), when you press to make a coffee and that point it's starts checking and throughout the grinding process.









I could never find it in the Varianza, because it could be behind the plastic in a thinner area, so you can't see it, equally it could be up inside the top of the portioning mechanism where it senses a lack of beans?

I would recommend cleaning the bean hoppers and blow some air in case anything is lodged on a sensor. As I am not familiar with the solo, if it has a portioning system, similar to the Varianza and Barista TS. By portioning system I mean it takes a set amount of beans and then grinds them out fully leaving nothing in the grinder (this is unlike any other BTC machine I have seen)....This system could have a jammed portioning slider, this happens when using less than good coffee with shards/brokens/very oily as they can sometimes jam it. Check for any jammed beans anywhere...In the machines I reviewed I think this gives an error number 14, I've only ever had it once though.


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## ward1e (Jul 6, 2017)

Thanks for the detailed response. I have already tried cleaning the beans and fragments out with a compressed air aerosol can.

I can't see any sign of an IR or light sensor from the outside of the bean grinder. I even removed the torx screw from the inside of unit to remove the grinder cover. I will take the unit apart and take some photos. It would be good to understand what exactly has broken and fix it if possible. It seems unlikely the bean grinder has randomly broken so I suspect it is a sensor or electronics fault somewhere.


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## DavecUK (Aug 6, 2013)

ward1e said:


> Thanks for the detailed response. I have already tried cleaning the beans and fragments out with a compressed air aerosol can.
> 
> I can't see any sign of an IR or light sensor from the outside of the bean grinder. I even removed the torx screw from the inside of unit to remove the grinder cover. I will take the unit apart and take some photos. It would be good to understand what exactly has broken and fix it if possible. It seems unlikely the bean grinder has randomly broken so I suspect it is a sensor or electronics fault somewhere.


Yeah, for the life of me I cannot find the Varianza sensor either, although their must be one....I just really don't want to take it apart to find out. It's rare for this type of sensor to fail (think about how reliable TV remotes are), so I hope it's just a loose wire or a cleaning job.

I think the low bean hopper sensor on many of these BTC machines is where manufacturers can be too clever by half and it would be great if they added an ignore/disable bean level sensing function to the firmware. Why put something that prevents you from using the machine for a feature that might go faulty, but wouldn't prevent the machine from working. Trouble is programmers are very binary in their thought processes


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