Elektronik Gaggia Titanium electronic components main board

[RobertdB]

Hallo,

Mein Deutsch ist nicht sehr gut, deshalb versuche ich meine frage ins English zu stellen, verzeihung.

The problem with my Gaggia Titanium is the it stays in AUTOTEST for days and does not progress. I have checked in the service menu the grinder motor, dosing solenoid, and brewgroup. All is working fine.
After testing the components on the main board, I found that the opto to drive the Triac for the boiler is faulty. The Triac is testing OK but the driver opto (-diac - triac) is giving weird numbers. I have tried to google the component, with markings SW42S4 foto in the attachement, but did not find any match. Can someone help me to find the the piece or a replacement in order to repair my machine?

It has produced over 50.000 cups of coffee and I hope I can make another 50.000 cups with it .

Before the problem occured, the machine was spontaneously resetting itself and changed language every now and then. After replacing the backup battery ( 1 year ago) it was working fine again. I bought the machine in 2009 and only had to replace the high pressure water lines.

Gaggia Titanium
Software version V1.06.2
Production date: 2008 10 14

Mit freundlichen Gruss,
Robert

 

[RobertdB]

After an intensive search on the internet I have discovered that the part in question is from Sharp.

http://www.sharp-world.com/products/device/lineup/data/pdf/datasheet/s2s4_e.pdf

The S stands for Sharp and the following W4 is a date indicator. So I had to search for 2S4...

Hope this info is of some help to someone.

 

[uhrmacher]

Check the 470μF capacitor, it is responsible for the ongoing self-test.
The optocoupler would have to be from Sharp

 

[RobertdB]

Uhrmacher, thank you for your help, I will check tomorrow. The capacitor is C13 on the main board, close to the transformer?

 

[uhrmacher]

yes

 

[RobertdB]

I have checked the capacitor and it was reading 408 micro fahrad. Not within the specs range. Replaced the capacitor but still continues to show self test. I have the impression that the main board is waiting to receive a "valid" temperature reading from the boiler before it continues with the selftest. So I have to find the opto S2S4 from Sharp or is there an equivalent?

 

[uhrmacher]

The capacity is not the biggest problem, the internal resistance is more significant. The internal resistance can only be measured with an ESR meter. If you do not have one, replace the capacitor.
If she still does not heat then we keep looking
For the test, you could swap an optocoupler. e.g. from the cup heater!

 

[RobertdB]

Thanks for the suggestion of replacing the optocoupler from the cup heater. I think that is IS02 connected to triac T3, correct?

 

[RobertdB]

Sorry it is IS07 connected to T3 and JP14.

 

[RobertdB]

So I replaced the boiler optocoupler with the one from the cup heater. Sadly no luck..
I will exchange the triacs now from the cup heater and the boiler. Let's see if that helps.
The voltage reading over the hot side of the optocoupler is 233 volts.

 

[RobertdB]

What I find strange is that I have voltage readings between the black wire on JP15 and respectively the pump and the cup heater of 61 and 86 volts AC. The wireing schematic that I have is not very clear on the wires around the boiler and its thermostat.

 

[uhrmacher]

there is a diode in the pump so the voltage across it is never 0 volts

 

[RobertdB]

I have exchanged the triacs and replaced the 470 uF capacitor again. Unfortunately the coffeemaker stays in AUTOTEST mode.
The connector for the boiler has a second triac BTA12 connected to the heatsink and this one is also driven by an optocoupler. This is what I am going to test next.

 

[RobertdB]

I have tested the triacs and they seem to be OK. I also noticed that there is a second opto isolator ( IS02 which is also connected to the boiler triac) for the boiler. Replaced that one but still no luck. The machine continues the "AUTOTEST" stage. What can I check next to repair my machine?

 

[uhrmacher]

Do I understand this correctly, it is always only Autotest in the display? What is the voltage at the output of the voltage regulator?

 

[RobertdB]

Yes that is correct, When I start it up it displays only "AUTOTEST", no further sound or display.

The voltages on the voltage regulator 2904 are 17.5 volts on pin 1 and 4.99 volts on pin 3.

 

[uhrmacher]

Can you initiate the test mode?

 

[RobertdB]

Yes, I can initiate the test mode. I can test the grinder, the thing that compacts the coffee, the buttons etc. with no problem.

 

[uhrmacher]

what temperature does the test show from the temperature sensor

 

[RobertdB]

I am not sure how to get the temperature reading. What I did find is by pressing buttons 3 and 5 simultaneously the display reads: 2 5 6 9 D

When I press buttons 1, 3 and 5 simultaneously when switching the machine on I get in the diagnosis option the following readings:
heater parameter K1 8
heater parameter K2 31
heater sensor adjust 96
temperature normal 86
temperature high 101
temperature 1° coffee 105
temperature steam 125
hot water pump regulat 63000
machine status 48
among with some other settings.

Is this what you mean?