Grinder will not start

[monts]

My Royal professional coffee bar grinder will not start. I can brew coffee using the bypass with preground coffee. In test mode, pressing the number three button will also not activate the grinder, but the number three will show up in the display while the number three button is depressed. The number 128 is displayed on the lower line of the test mode. Any ideas?

 

[monts]

Post should read:

My Royal professional coffee bar grinder will not start. I can brew coffee using the bypass with preground coffee. In test mode, pressing the button number three will not manually activate the grinder, but the number three will show up in the display while the number three button is depressed. The number 128 is Displayed on the lower line of the test mode. Any ideas?

 

[Advocat]

My Royal professional coffee bar grinder will not start. I can brew coffee using the bypass with preground coffee. In test mode, pressing the button number three will not manually activate the grinder,
Any ideas?

Grinder Triac(s)?

 

[monts]

I have a meter. What are the values? are measurements taken while the machine is on or off? (My electrical knowledge is somewhat limited although I have a basic understanding and can follow instructions).

 

[monts]

In the meantime, I tested the following:
With the grinder cable disconnected during test mode, JP2 shows 30 volts with the number three button pressed, and about 15 V while #3 button not pressed. With the grinder cable connected to JP2, I receive no voltage in test mode (whether number 3 button is pressed or not).
With the grinder cable disconnected, I get approximately 18 ohms (200 scale) across the grinder cable plug.
My machine is 120 V

 

[ksb]

Check the triac:

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/CD00002383.pdf

as follows:

1. disconnect from mains!!!!
2. Measure resistance A1-Gate
3. The value must be a few 100 Ohms
4. Measure resistance A1-A2
5. Connect A2+Gate together
6. The resistance must decrease to a few ohm

 

[monts]

Here are my results for A1 to gate resistance.

T5 .361 ohm
T6 .358
T7 .366 (for comparison)

Resistance was not measurable between the other terminal A1 to A2 or A2 to gate.

Do these values show a properly working triac?

 

[ksb]

If this values have the unit "kOhm" it seems to be ok but it is the first of two necessary measurements.

Now short A2 + Gate together and measure the resistance against A1.

 

[monts]

First of all, thank you so much for hanging in there with me.

All measurements remain the same, shorting A2 with gate and then measuring resistance against A1. (all around .360).

The grinder worked perfectly until I opened up the machine yesterday turned it on its side and used compressed air to clean out the inside.

 

[ksb]

Does the dosing feeder work in the test mode?

Does the feedback of the dosing switch work?

 

[monts]

Yes, in test mode, pressing button number four activates the dosing solenoid (the door opens and closes).

 

[ksb]

But is the feedback of the switch working?

Normaly this is the "3" in the upper line of the display.

 

[monts]

In test mode the top line reads 56 89. The bottom line reads 128. As I press the number three button, the top line remains the same and the bottom line only shows the number 3. When I press the number four button, the bottom line changes to the number 4 and the solenoid is activated.

Is it possible to call you?

 

[ksb]

OK - the "3" which is shown in the upper line of the display indicates, that the chamber is filled with coffee.

Sorry - i cant help you on phone because i have to think to long for an answer

 

[ksb]

Did you change any connections?


Is the brewing group working?

 

[monts]

The brew group is working in test mode (and if I use the preground coffee bypass). You mentioned the number 3 in the top line. I do not show the number 3 in the top line, only in the bottom line while pushing the third button in test mode.

 

[ksb]

You can see the "3" in the upper line only, if the dosing champer is filled which is only possible if the grinder is working.

Only if the "3" is pemanently displayed the grinder will not work.

 

[ksb]

Please repeat:

Which resistance did you measure at the grinder motor?

I think about 20 Ohm (Your machine is a 120V-type)?

Which voltage you can measure on "JP2" while the grinder is activated?

 

[monts]

Grinder resistance is 18 across the connector. My machine is 120 V.
In test mode, with the grinder disconnected, I measure 15 V at JP2 and approximately 30 V while pressing button number 3. If I plug in the grinder, there is no voltage at JP2 even with button 3 pressed. To your question above, I can get the number 3 to display on the top line by depressing the micro switch, so that is working as well. What else can I check? Are there any terminals that I can use to power the grinder directly?

 

[ksb]

The grinder needs about 100V DC so you can't check it with mains voltage (AC).

As you told me the machine worked fine until you opened it and cleaned it by air.

Is it possible that you damaged one of the big white resistors?