Siemens EQ.7 Z Coffee Machine TK76209RW/05: No Power, Checking Control Module & Display Options

Question

The Siemens EQ.7 TK76209RW/05 espresso machine, after connecting to the socket and turning on the power switch, does not give any signs of life. The display does not light up. 230 V voltage is supplied to the control module. There are no damaged elements or burnt tracks on the disc. I tried to...

Piotr2608 · Answer

Take a picture of this module.

dzi_dziuś · Answer

At the very beginning, check the resistance of the indicated resistor and compare it with the value read from the strips http://serwis-tv.com/opornik.html
You can also measure the voltages on electrolytic capacitors, just don't hurt yourself and short circuit :)

remek_g · Answer

The resistor value read from the strips should be 100K and within tolerance. The voltages on large electrolytes are trace. On 3 it has 3.8 V and on the other 0.2 V.

dzi_dziuś · Answer

Nothing on the marked capacitors either? Are you measuring on the VDC range?

If the measurement was done correctly, it would indicate a fuse - a white cube that fits in the drawn circle. If it has a break, it would be appropriate to determine why it burned out. At the beginning, you can check the rectifier bridge, 400 V short-circuit capacitors and the LNK 304 converter system itself (resistance between the 5th and 7th legs).

remek_g · Answer

Actually the fuse (FTR2F 10 ΩJ...) is blown. In the connector, the appearance of the fuse and the fuse manufacturer's card. I don't know how to decipher the markings and what to replace them with?

CCMTher...pdf Download (1001.33 kB)

WP_2016120..001.jpg Download (336.31 kB)

- the bridge only allows about 3 kΩ in one direction - it looks good
- 400 V capacitors are not short-circuited
- The LNK304 between the 5th and 7th legs is 1 MΩ one way and 4 MΩ the other way. I don't know what the values should be.
Anything else to check?

dzi_dziuś · Answer

It is a 10 Ω, 5 W, cement fuse resistor. To check the bridge, you need to check each diode in it separately. If you exclude this, you can risk replacing this resistor / fuse and connecting the module. Buy some just in case

remek_g · Answer

In the bridge, I checked the transitions between each pair of legs and it's ok. If it has capacitors and the LNK403 chip on top, isn't it worth soldering in new ones?

Piotr2608 · Answer

The system consists of two converters. I do not see the LNK circuit within the damaged resistor.
The element is responsible for the operation of this converter FSCM0465R and you need to replace it. Also diode D1 should be checked.
Anticipating the question - I do not know the replacement for this system and the system itself is available in China. Maybe the layout will fit DM0465R (FSDM0465R) . The casing differs from the original.

dzi_dziuś wrote:
First, check the resistance of the indicated resistor

This resistor is not the resistor you thought of

If anything, this resistor should be behind the cube - you can see a green element (perhaps a choke) within two capacitors, most likely 4.7µF 400V - the second LNK304 based converter.

PS FSCM0465R I found 2 pieces of this system if anything.

remek_g · Answer

Thank you all for your suggestions. I found an identical machine with a damaged brewing module and used it for parts. After replacing the board, the device works.

lukasz696969 · Answer

Hi,I know this is a really old post, but I was wondering if someone would know what component is located on the C26 position of this board. The reason I ask is because last night my machine tripped the fuse while making coffee, and after checking the control board, I found the following component blown.

tomo24 · Answer

Hello This is a TRIAK ST T4-3570 4A 600V.

ETsanov · Answer

Hello and happy new year!
Does anyone know what is the breakdown voltage of D16? The blue strip indicates it's a zener but unfortunately the voltage is not specified.

P.S. I used an image uploaded by the previous commenter, hopefully it's not a problem, forgot to take a picture of my board ...

Regards,
Emanuil

slawek1111 · Answer

D16 is the MBR0540 schotky diode

ETsanov · Answer

Thank you very much, the machine is now fixed.
Leaving this for future reference if someone has a similar situation:
My machine worked sometimes and sometimes upon turn on the lcd would just light up briefly and turn off - leaving only the power on button light. When that happens it does not respond to any button presses either.
Traced the issue to near the lcd connector - the second lcd wire is around 2.5 - 3.2 volts when the machine is working like it's supposed to, and 5v when it's not working at all. Ended up replacing Q3 and Q4 NPN transistors with new BC517 which solved the issues.
Again - thanks for the help!

Siemens EQ.7 Z Coffee Machine TK76209RW/05: No Power, Checking Control Module & Display Options

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