CMA Astoria CK auto fill not working - Page 2

Equipment doesn't work? Troubleshooting? If you're handy, members can help.

#11: Post by jpboyt »

The red light, which some of the machines with the MFC2SN controller have, is a warning light that the reservoir is empty. The two sensor circuits on this box are Sonde Serbatio (reservoir) and Sonde Livello (level) and the red light is on when the S. Serb sensor shows no water in the reservoir. This sensor has to be satisfied to energize relay K1 (single pole dual throw) that provides power to relay K2 pump and relay and to allow group to be energized. Not sure how and when you had the red light come on but that's the function of the light. Here is what I have for notes on this control:
NO SENSORS: K1 Normally closed contact energizes light.
S.SERB ONLY: K1 Switches to NO position. Light goes out. K2 NO closes energizing pump and Autofill solenoid. Provides source voltage to allow use of group. Time out on this sensor will leave group power only.
S. LIV: K1 NO closed, K2 NO open, and K3 NO closed.
So with both sensors satisfied you have no light, no power to pump and autofill, and power to the element and group.

I suspect that you had a couple of things happen at once so you got overlapping problems. If you had a bad pump relay then you would have had the pump and autofill time out. Hope this will help. As far as the logic components go, I rarely see problems. I am also curious what the story behind the arcing on the back side of the AC board.
This control is used in the Nuova Simonelli Oscar if that may help a bit.

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FOCKER (original poster)

#12: Post by FOCKER (original poster) »

Some updates
Ichanges de operational amplifiers. lm 324 and lm358. I conected the board to the machine. plug it in and power on... The pump start to fill the boiler, I say "It's Solved" but the the boiler is flled up and the pump is still working
I emptied the reservoir (it supose to cut averything, and light up the red light) but the pump is still working. Is like the pump and ev relay was permanent connected, I though that the ic Was bad, so i changed them back to the orignals. Thats supose to sned me back to square 1. I connect The board again and the pump relay kicked on again!!! Now I have a new failure.
Some component in the board is in short circuit. I tested the operational amps and they are well welded. I'll have to check al the smd resistor, diodes and capacitors, one by one to find the short
The faliure is electronic. The circuis is old and simple, 2 operational amps and a buch of resistors, diodes and capacitors
If i can't find the short I'll check the board with an osciloscope as a last resourse
I have confidence that i'll repair it
I'll keep updating what ever goes on.

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FOCKER (original poster)

#13: Post by FOCKER (original poster) »

It's been a while, After serched a lot i found some circut schematic from a similar control box
RL0 1E/1S/3C/F

Is not the same, my control board is MFC2SN and in cafepars can be found Rl0 1E/1S/4C/F

The schematic show the same 2 amp- op as mine, i bealive that the diference is that mine has 2 level probes, 1 for the boiler and 1 for the reservour

Could i use ths schematic as a reference?
Does any one know the diference between the two boards?

This is the RL0 1E/1S/3C/F

And this is mine equivalent RL0 1E/1S/4C/F

Here is a Zip file with the Schematics