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canuck the pro
canuck the pro, Plumber
Category: Appliance
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Experience:  Plumber
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I have a Siemens fridge freezer. When the mains supply is interrupted

Resolved Question:

I have a Siemens fridge freezer. When the mains supply is interrupted the freezer fails to restart. This happens consistently. Usually I unplug the appliance for 30mins and it restarts when switched back on. Now it's failing to restart. I can hear the control unit switching the compressor on, but it doesn't stay on.
Submitted: 3 years ago.
Category: Appliance
Expert:  canuck the pro replied 3 years ago.

canuck the pro :

Hi, my name is ***** ***** I have been in the home improvement and repair field for 20 years. I will be very glad to help you today. Do you have any frost building in the freezer especially around the vent? Does the compressor actually turn off or does it stop running? Is there any error lights on?

Customer: During normal operation the freezer runs perfect.it maintains the correct temp of -21
Customer: i had to turn the mains off a few times over the past few days, as we are having some electrical work carried out. Each time I put the mains back on the problem occurs ,
Customer: after several attempts of unplugging it , it finally restarts until yesterday. Now I can't get it going. I've offloaded our food to another freezer.
canuck the pro :

When it is not working are there any lights at all? If you are intending to repair this yourself, remove the PCB and inspect it for any scorch marks on the back or any capacitors that are bulging or blown.

canuck the pro :

Full Size Image

canuck the pro :

The capacitor top on the board must be perfectly flat. Pictured is a capacitor that is blown.

Customer: Hi Mike,
canuck the pro :

Hi there

Customer: Hi Mike, the lights on the display are normal. All that happens is the controller switches on the compressor which runs for about 3 seconds and stops. Where would the circuit board be located?
canuck the pro :

There is a panel on the back of the fridge. You will see a square panel and the printed circuit board is there.

canuck the pro :

I am about to drive the boy to school so I will be away for about 30 minutes. I will have my cell phone with me so if you have further questions I will try to check when I am out. Worst case I will be back in 30 which will give you some time to check it out, ok?

Customer: Sorry Mike, I'm also going out. I won't be back until later this afternoon. Is the panel behind the cooling pipe matrix?
canuck the pro :

No it is not. I will be online for the next 12 hours or so. If you have any questions I will be here

Customer: Hi Mike, ok, I'm back home now. You ment
Customer: Sorry, you were talking about the circuit board. Could you tell me where to find it please.By the way after restarting the freezer it's now working. Which is good but I want get to the bottom of this, so it doesn't repeat the problem.
canuck the pro :

On the back you will see a small panel. Remove that and you will find the PCB. Be sure to turn the power off if you plan on touching anything.

Customer: Ok, I'll need to wait for a while as there's cooking going on at the moment.
canuck the pro :

No problem

Customer: Hi Mike,
Customer: i've taken the cover off of the circuit board, but all looks ok inside. No burning marks or damage that I can see.
canuck the pro :

How do the capacitors look? Are they perfectly flat?

Customer: Is this circuit board something that I could buy?
canuck the pro :

Sure. It is an expensive guess though. Did you see the picture I posted much earlier? The capacitors are the battery looking things. If the top is not completely flat that is what the issue is. In the picture I posted they are capacitors that are blown.

Customer: There is 1 capacitor which looks ok. Plus a couple of transistors and what looks like a relay.
canuck the pro :

Scorch marks would be on the back of the board. Can you send a picture of the board especially the capacitors? Do you have a multimeter and do you know how to use it?

Customer: Yes I'll take a photo. I've got a meter.
canuck the pro :

Do you kind of know how to use the multimeter or are you quite experienced with checking voltages?

canuck the pro :

I will hang in there for the pictures.

Customer: Hi Mike, have you an email address I can't seem to paste it into this text box?
canuck the pro : ***@******.***
Customer: Sent the photo to your email!
canuck the pro :

Yes the capacitor looks good from what I can tell. Is there any fray in the plug and are all the connectors on the board pushed in all the way? The problem just sounds like a loose connection but could be the board.

Customer: I took each connector off and pushed them back on again. I've plugged into the mains and the freezer is trying to restart but dropping out again.
canuck the pro :

Any buzzing from the capacitor?

Customer: No, no sound until it c
Customer: the relay clicks to restart the compressor.
canuck the pro :

Does it seem to take the same amount of time to start up? Are you sure that it is not part of the start up process?

Customer: After switching on supply it takes around 30seconds, but after this Each time it tries to start takes about 3mins
Customer: And switches off after 2secs
canuck the pro :

So now it will not stay on like it did before?

Customer: Correct, back to square 1 again. I would now unplug it for 20 mins before trying again. This used to be the cure until yesterday.
canuck the pro :

Got to be that capacitor is not storing power. It is either that or there is a cold solder joint on that board. If you can solder I would replace that capacitor and touch up the solder joints on the back of the board. Any solder joint that looks dull compared to the shiny ones would be a cold solder joint. Make sure that you get the exact capacitor. The numbers are printed on the side.

Customer: Ok, I'll give that a try! Thanks Mike.
canuck the pro :

You are very welcome. Sorry that was such a long trip. I just don't want to give bad info.

Customer: No problem, it's a strange fault! Cheers John
canuck the pro :

Cheer to you!

canuck the pro :

If something comes up I will be here. You can still ask questions even after rating my service if something does come up. I will always respond. Mike

Customer: That's really helpful Thaks!
canuck the pro :

You are very welcome. I want you to be totally crazy satisfied and tell all your friends what a good experience you had....hopefully when your next question about something comes up you will request me directly too! I am an expert in Home Improvement, Pool and Spa, Appliances, HVAC and Plumbing.

Customer: Hi Mike, just out of interest, would I need to go to Siemens to by the circuit board or is there an alternative supplier?
canuck the pro :

You should have an appliance supply near you that you can order it from. That would be the most reliable and the most expensive. You could order off of Ebay which is a little risky but if you order from a supplier with a return policy that is very good and the least expensive but you may get a board that is DOA. Make sure to cross reference the numbers on the board and the model number of the freezer to be certain. If I am trying to save money I get used or refurbished boards on Ebay myself.

Customer: Ok that's a great hep, thanks again!
canuck the pro :

You are very welcome!

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