Saeco Vienna (mio-star intermezzo) SUP 018 CD - Brew Unit Blocked - coffee beans empty

[roberto45]

HI,
I have a Saeco Vienna ( mio-star intermezzo) SUP 018 CD 230 VAC 1250w.

I will start explain you in sequence all.

1. In the display showed the message coffee beans empty. The sequence to make coffee start and you see how the grinder works.. but after seconds stop the machine and showed the message coffee beans empty.:
Action: I checked the microswitch that control the dose of coffee, into the brew unit. There is continuity when is closed around 0.6 ohms. checked the wiring until the connector JP31 on the PCB of the display, continuity and isolation, satisfactory.

2. Tried several times to operate the saeco without success, and the last chance appear another message: BREW UNIT BLOCKED.

3. I found in google several actions to do due these message BREW UNIT BLOCKED.

Action: -checked the brew unit ( I dissassembly and assembly) all satisfactory.
-I did the test through the display to check how is work the brew gear motor and i saw that works very slow.
- Dissassembly the gears and the motor I checked not damaged and the motor coil 20 ohms.
- the two microswitches installed in the gears checked continuity when is closed and when is opened. satisfactory.
- I checked the voltage that arrives to the motor was only 5 vdc. NO GOOD
4. Finnally due the voltage arrives to the brew gear motor only 5 vdc I found that the cause will be the Transistor TIP33C.
I replaced the transistor TIP 33c.
5. After replacement of the transistor i check the function of the brew motor through the mode test i was working several times very good arrives to the motor 28vdc.

6. But I wanted to check the problem of Coffee beans empty I touch the microswitch of the dose coffee. and then after that action the motor left to work properly
only arrives to the motor 13vdc.

I think the real trouble was the message COFFEE BEANS EMPTY that did the brew gear motor not works good. I removed the Transistor TIP33c to check if broken
the transistor is ok.

The real problem comes from one component in one of the both Printed circuit board, somebody can help or support with this please?

Many tahnks in advanced.

 

[Grisu]

You must not mix up those 2 very different failures.

TIP33C (better replacement is TIP35C from Conrad or a BD249C but later need for isolation!!!) is for brewing motor, it's DC and max 33V.
The circuit limits brewing motor voltage to <=35V.
If it is too slow mosty TIP33C is faulty.
Same if little too fast when voltage more than 35V while motor runs free or with little load.
Maybe too much testing killed it.
If the voltage is between 20V (under full pressure) to 35V (free run) it is ok.
Often people damage print while changing this transistor or solder bad contact.

About grinder check motor brushes, it is a 230V DC motor. You can test with old fashiond edison lamp 60W, should fully light while grinding.

Bean empty will come if after 20s grinding and the dose contact wont close within time.

 

[roberto45]

Hi,
Thanks to answer Grisu.

Related to the transistor I removed to check if it works and still works, but is it true when i removed the was damaged the cirvuit in the pcb, anyway i will repair.

The grinder all the times was working, the problem the part of the sequence after grind the coffee not open the door to put some dose of coffee into the brew unit.

please some advice what component in the pcb could be faulty? or if somebody has the wiring diagram of the pcb will help a lot of to understand.

thanks in advanced.

 

[Grisu]

This should help you: Elektronik - Schaltungsunterlagen SAECO Vienna SUP018 Platine M5AV1-8

 

[roberto45]

Thanks again Grisu,
I see, i will check the triac, if works good.
the bridge diode and the diode is checked and works well.

the other thing is the tassen füllmenge, in my saeco is belongs another pcb and dont have potetiometer.

 

[roberto45]

my platine is pn M5DPWRV19.

 

[Grisu]

sorry cant help any more, dont have a Vienna, maybe others jump in and could be more help.

 

[roberto45]

Danke für hilfe Grisu

 

[Majolika]

roberto45

take a look at these switching documents, maybe you can handle it better.

Elektronik - Schaltungsunterlagen SAECO Cafe Nova SUP018DR

Hallo, zusammen anbei eine Verbesserung der Schaltungsunterlagen für die SAECO Cafe Nova SUP018DR. Es ist die 4. Änderung mit dem Änderungsstand 1.4 vom 11.02.2016. Diesmal waren am Stecker JP 6 der Leistungsplatine die Pins 12 und 13 falsch geschaltet (vertauscht) sowie der Stecker JP6 in der...

saeco-support-forum.de

Models with a display
(test mode and diagnostic mode cafe nova) are on pages 13 and 16

https://www.kaffeemaschinendoctor.de/saeco/vienna/vienna_reparatur/Service_und_Reparaturanleitung_Vienna_Cafe.pdf

 

[roberto45]

Thanks Majolika, there is much information in the wiring diagram.

 

[roberto45]

Hi again, finnally I replaced the transistor with pn tip35c and as well the triac belongs to the circuit. but without success, I checked the voltage at the JP8 plug/ connector in the Printed circuit board and there is only 15 vdc not good voltage to move the brew motor.

Any idea?

Could be the diode bridge or zener diode?


Thanks in advanced

 

[Grisu]

Put middle yellow and red wire out of connector and shorten them (outside of plug).
Now 33V limiter wont be active, is it now with full speed?
If yes there is something wrong with the 5 components of 33V limitation, otherwise somewhere else.
It wont hurt for testing that voltage may go above 33V now.

 

[roberto45]

Hi, not i did as you say removed red and middle yellow and short them.
I enter through the mode test to check if works the brew motor unit and then seems to work but after less than 2 seconds stop. not working at full speed.
not possible to measure the voltage in the plug because is cut before i can measure.

????

thanks

 

[Grisu]

Is the motor ok, brushes long enough?
Is resistor 125 Ohm (second little heater) ok on wire yellow/yellow?

 

[roberto45]

Guten morgen Grisu,

yes the resistor heater is ok 125 ohms.

Brew motor has 25 ohms.

After did this test not arrives voltage to plug jp8.

NOTE: the first time i replaced the transistor TIP33c for the same part number, TIP33c was working properly, but after several test was stop works properly.


????

Thanks for your help.

 

[Majolika]

Hi
Always ahead that the brew group has been disassembled and cleaned
was greased. so that you can make your movement very easily.

look through that again.

Saeco Support Forum - Einzelnen Beitrag anzeigen - [erledigt] Platine Vienna

Post 57967 - Saeco Support Forum - Hilfe und Fragen - alles Rund um Kaffeevollautomaten

www.hmilbradt.homepage.t-online.de

 

[Grisu]

We dont know which board you have, there are different ones in Vienna series.
Think I cant help you any more, never opened a Vienna.
You can check Triac and its gate resistors.

 

[Gast28056]

Mahlwerk ohne Funktion

Hallo zusammen, Ich habe folgendes Problem an meiner Saeco Royal professionell das Mahlwerk mahlt nicht mehr. Folgendes geprüft 1.Motor läuft wenn ich ihn bestrome 2.alle Microschalter geprüft ,auch die Kabel. 3.im Servicemenü lässt sich der Motor auch nicht steuern. 4.an der leistungsplatine...

saeco-support-forum.de

 

[roberto45]

Many thanks to all, i will replace the zener diode and the varistor.
When I checked the the diode bridge connected in the PCB with a multimeter when i make the last mesurement dont give the double of the two diodes, 1. 0.578v 2. 0.578 3. 0.578
normally in the last check number 3 has to be the double,, but in this case is only like one diode,, could be because is connected ?? any idea about it?
many thanks in advanced

maybe i will replace the bridge as well.????

 

[Grisu]

Desolder the bridge and measure each single diode in it, all 4 in both directions, one 0,6V and other infinite. From - to both ~ and from both ~ to +.
But it should work when you tested without this circuit, so I dont think it is the main reason of your failure.

Is the grinder working? If not its the common triac for both grinder and brewing unit motor.