Repairs of household appliances aren’t generally my field of expertise, but in some cases, it can be a very rewarding activity. Some particular models of clothes dryers (“AEG”, “Whirlpool”) common in Europe use a control board, and this is not designed up to standard. The design flaw, it renders the machine inoperative in the very sense, you can’t switch it on, and it doesn’t show anything on the display. Typically, this occurs after roughly 3 years of service….
This is the control unit:
After a quick inspection, it is fully clear that the defect rests with the control board, model EDR0692XAX. Easy fix, just get a spare! Well, easy, but outrageously expensive.
The defect, it is related to a DC switch mode regulator converting mains voltage down to some useful voltage to run the controller. This is a step-down converter, NOT mains insulated!
Two dead parts were found, the LNK304 switch mode converter circuit, and a 47 Ohms resistor.
The LNK304GN is easily found, and replaced. The resistor: WATCH OUT! This is a fusible resistor, NEVER replace with just a common resistor – it will potentially set your house on fire, when the next switch mode failure happens.
The 47 Ohm resistor, it’s a 3 Watt resistor, and the ULW3 series, available from all major suppliers, should be a good replacement.
This is the failure charcteristics of the ULW3 resistors – it will go open circuit if overloaded, without release of any flames or particles. It a hybrid, partly fuse, partly resistor.
Hi,
I have the same problem with my dryer.
I have two questions:
1. how can you tell it’s a 47 ohm resistor?
2. do you know if there is a datasheet for this board?
thanks for the help,
Alphred
Hi, Yes, it is a 47 Ohms resistor. I could not find any datasheets for this board.
Simon
I have the same problem and it is written on the resistor 47R 3w where 3W means 3 whatd and R47 means 47 ohm I hope this helps .
It’s Sunday do I will try to find the parts in local shops tomorrow.
Hi,
Very useful article! Most likely also seems to be the issue with my Dryer. Where online can I buy these two parts in Europe? Where on the circuit board do I find the LNK304 switch (on the topside or down side of the PCB; if you can indicate the two parts in your picture?)
Thank you for the help!
CM
Hi, You can find these on ebay or other supplieres no problem. They are widely available. The resistors need to be flame proof. Normal resistor will be a fire hazard!! The part is easy to find on the board otherwise just send a picture of the board.
Hi Simon,
Thanks a lot for the reply.
My circuit board looks exactly like yours (EDR0692XAX). So if you can point the IC on your control board picture, then that should suffice.
Otherwise, I couldn’t find any IC on the front side of the board with 7 pins. LNK304GN in your schematic shows 7 pins, the 6th one is missing.
Thank you again for helping out.
Regards,
CM
Hi, the IC actually on the other side, so you can’t see it on the picture. But it is easy to find. You have to take out the board from the holder by pushing back the white plastic tabs on the holder/case. This may differ slightly from dryer to dryer. Simon
Hi – hoping you can help me ! My Mum’s Bosch dishwasher failed, no power to panel etc. I suspect a LNK304 failure and can see the subsequent AC input resistor failure. The resistor obviously heated up and has discoloured the bands so I can’t see what value it was. I am suspecting either 22 Ohm or 47 Ohm. We are on 240VAC over here if that makes any difference.
https://dl.dropboxusercontent.com/u/973862/bosch/IMG_0299.JPG
https://dl.dropboxusercontent.com/u/973862/bosch/IMG_1176.jpg
Any help appreciated !
Hi, I assume it is a 27 Ohm resistor. Make sure to use a fameproof resistor, 2 or 3 Watts. You might also want to check the big capacitor close to the LNK304. Simon
Hi
Please i have the same problem with a fagor washing machine. The LNK304GN and the resistor.
I want to ask if there is any equivalent for this part
Hi, Many Thanks. Ich have a Zanker KTH 72701 PE with the same board inside. Ich repaird it as desceibed ans it work perfect again. Ich save 500€.
Wolfgang
Super!!!
hi simon!
very helpful your advice
many thanks!
I have the same problem
just want to ask which is the LNK 304 from the 4 same swithes on the pcb.
And how can i check if is damaged via a multimeter?
Also which is the big capacitor close to the LNK304?
many thanks again
Hi George, First, I would check if it has any visible damage, and if it has a short between S and D pins of the LNK304. In any case, it may be faster just to replace with new parts. The capacitor, unfortunately, I don’t know the value. Did your capacitor burn or got lost? Don’t think it is too critical, a similar value than existing may be good enough.
thanks!
i fix it.
replace LNK304 as you adviced.
many thanks
Hi Simon!!
how are you?
I need your help again!!
My AEG T59850 (91609653100) Tumble Dryer is operating fine, dryes the clothes, but I find no water in the waste reservoir!!
Could you please help me, what the problem might be??
many thanks again.
George
Hi, normally thats because of the condensor not working. First I would clean the condensor from dust from all directions. Then check if the fan and air flow cooling the condensor is working. The condensor is the aluminum part that has many small openings.
hi mr Simon
glad to hear you again and
thank you very much.
I check it again, and I clean the condensor.
I have some water down to the waste, and does not pump it to the reservoir tank.
the fan, is not working.
So I have to replace the fan first?
how about the water pump?
please advice me how i can start to solve this problem.
thank you in advance.
George
sorry the big fan is working. I open the waste water port and i have fan flow.
air flow
sorry
If you have cleaned the condenser, and if the fans are working, then it could be the water pump. There should be water collecting somewhere inside the piping near the condenser. You can also remove the water pump and water should flow out
hi again
the big fan at the back of the machine is working.
the small one in front of the compressor, near the condenser is not working at all.
this small axial fan is for cooling the condenser?
How i can check the pump? Is there any switch, for water level to give the pump the signal to start?
The water pump has any capacitor?
many thanks again
It seems like the problem ks with the cooling fan of the condenser. The pump has various designs normally no capacitor.
hi mr simon!
i have an aeg T59850 (91609653100) Tumble Dryer.
I want to ask some information please.
The compressor’s high temperature line is about 65-70 oC and the low pressure, temperature 22-24 oC.
So the condenser does not condenses water.
what are the correct temperatures, if the compressor works fine?
Could you please tell me what type of refrigarator liquid / gas the compressor is opperating?
Can I add liquid /gas if there is any leakage, and how?
many thanks again.
George
Hi, the correct temperatures are about 60-70 and 20-25 so your heat pump seems to work fine.
The refrigerant gas, I don’t know for your unit but is should say it on the label. Many use R134A, and quantity must also be shown on the label is should be about 250-300 grams.
Maybe heat exchanger is blocked or air circulation fan not working.
ok mr Simon, thank’s
so if these temperatures seems to be ok,
is a bit strange, because I cleaned the heat exchanger very well, and also the air circulation fan is working, I can feel the air if I open the front door.
The drum is circulating both sides.
The water pump / water limit switch is ok.
The machine dries the clothes, but it need much more time, and I don’t find any water at all, anywhere, in the waste or the water tank.
So could you please tell me if there is anything else that it will prevent the machine from condensate the water?
many thanks again!!
If all that works there is nothing else. Maybe fan can have insufficient air flow, but it is rare defect. Or heat pump may not work fine under full load so I would check the temperature under full operation, e.g., after 40 minutes.