[Solved] Samsung WF80F5E0W2W - zero response and clear display does not turn on.

Hello.
The washing machine, as in the subject, came to me with a simple, so to speak, defect. According to my aunt (the owner of the washing machine), once you could turn it on, you could set the washing program and the washing machine was washing, and the next day by pressing the power button 100 times - there was no reaction - a clean display. I checked, the washing machine was turned on. I also checked the micro-contact on the control panel and it turned out that it was badly soldered (loose leg). After soldering and checking that it connects every time, I assembled the whole thing. Unfortunately, paradoxically now the washing machine is silent as if enchanted. I re-checked the connections between the modules and the control board to see if I had damaged anything during assembly. Everything looks ok.

So I suspect the power supply board with relays. Only that all electronics are flooded with waterproof gel. By the eye, you can't see burning or overheating of the elements, even under a magnifying glass. A thorough check of the elements is associated with the destruction of the anti-moisture insulation, not to mention the problem of picking the board out of the housing. Of course, this will not do without it if it turns out that the damage is there. What if the fault is in the programmer board. A schematic would be nice, but where? I am hoping for advice from more experienced forum users or service technicians. I don't expect "ready-made", but a good hint is half the battle.
I greet everyone.
płytka pro...a druk.jpg Download (2.35 MB) płytka zas...w żelu.jpg Download (1.79 MB) płytka pro... front.jpg Download (7.31 MB)

Samsung washing machines are one big unknown. Steel power cables with a small cross-section, not connecting and non-contacting contacts. I would start by checking if voltage is flowing to the control module. There were cases in several washing machines that the power cables had to be replaced. In one there was a voltage drop of about 40 V - there was a "low voltage" error, in others there was no supply voltage on the module.

Welcome back.
I checked all wires and connections. Also checked the individual components of the washing machine and they are operational, after all, the washing machine "was working just a moment ago". The power module went to the workshop. I picked it out of the gel, wondering why the manufacturer also covered the board with the gel from the printing side and SMD elements. I removed the gel from parts of the power supply and stabilizers.

After connecting both boards and applying power, the display came to life. It was possible to set programs, that is, everything is ok. I measured the voltage at the output of the converter 18V, at the output of the stabilizer 1 - 12.2V and at the output of the stabilizer 2 - 5.1V. After turning the power off and on a few times, the display behaved correctly, but after the last power on, no reaction. Measurements - output from the converter - continuous 18.5V, and on the 12V stabilizer (KIA78R12) the voltage 12.1V appears and disappears cyclically, and on the second stabilizer, the voltage 6.8-7.1V appears.

Instead of 78R12, I substituted 7812 for a short time. The voltage is 12V constantly, while on the second stabilizer it is 7.1V. I managed to turn on the display once, but it was not possible to set the program, and it was not possible to turn it off with the button, only from the network.

I also substituted the second 7805 stabilizer, but the voltage measurements were similar, i.e. about 7 V. I wonder what causes the supply voltage to increase to about 7 V, but my hands are falling, because I do not know where to look for the cause.

For several days I've been sitting and digging in the module and I'm still in black .... Maybe someone from the site will tell you something? It is a pity to throw away a three-year-old washing machine for scrap, because you will spend over PLN 700. for complete electronics, - it's probably better to add a few hundred and buy a new one, but I will definitely advise my aunt not to use Samsung.

jurek54 wrote:

After connecting both plates and feeding power, the display came alive.

How did you connect the power supply on the table (mark on the photo) or was it a normal connection in the washing machine? Swap this electrolytic capacitor ...

TONI_2003 wrote:

How did you connect the power supply on the table (mark on the photo)

I plugged it on the table and I gave the power to the relay terminals, marked in green. I connected the display board to the socket marked with the green arrow. And in a moment I will also try to substitute the flower beds.

There is a chance that you connected the plugs to the relays "back to front" because the cable is long enough then the washing machine will be dead.
Turn the plugs 180 degrees, blue stays blue and white stays white and try again.

mrhari wrote:

There is a chance that you connected the plugs to the relays "back to front" because the cable is long enough then the washing machine will be dead. Rotate the plugs 180 °, blue stays blue and white stays white and try again.

The plugs in the bundle are connected in pairs from individual relays, they cannot be swapped or rotated too much. Below I present a selected fragment of the board from the printing side;

TONI_2003 wrote:

Replace that electrolytic capacitor...

I did not have such an electrolyte on hand (10uF/500V), but I tried and substituted it. Effect - no changes, i.e. the power could be turned on, the display started, but it was not possible to set the program. It was also impossible to turn off the power button, and after turning off the network, another attempt to turn on ended in a fiasco. I will try to buy and change the 2QR2280Z inverter controller, but it seems to me that the fault is on the other side of the power supply: 12V or 5V.

Correct the solder of the micro-contact that you soldered. Clean from old tin and track from varnish.
Terrible snotty.

widaw wrote:

fix the microstatic solder you soldered. Clean old tin and nail polish.

Col. Widaw, apart from your spelling, I agree that the appearance of soldering points has a lot to be desired, but after completing the work on removing the defect, I always put the plate in order and remove residual rosin after soldering. Your post adds nothing new regarding the bug.

Hello.
The washing machine has been washing for several days. She did a dozen or so washes, and accumulated over these two weeks. In the PSU board I replaced the 12V controlled stabilizer (KIA78R12) and the 2QR2280Z inverter prophylactically. Happy family (aunt) and me too. I am sorry, Col. Widaw, that I treated him too abusively for right criticism.
Greetings to all.