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I'm trying to fix the cooker hood of my kitchen and I found that the problem is in the controller. The PCB has two burned traces, respectively to the electric source of 220V (neutral and phase... picture below). I think it is very simple to fix with some solder on the broken traces, but since I don't know the reason why they brake, I'm not sure it's safe to adjust the PCB with this simple intervention.

Any advise?

enter image description here

LAST UPDATE:

I remade the broken traces of board and mounted back in its place, the result is:

  1. The halogen light works (one of them, the other is broken). The corresponding button id the last on the right side.

  2. The second button from the left side (lowest speed of the aspirator) turns the LED on, but the aspirator doesn't start.

  3. Third and Forth buttons from the left side (intermediate and highest speed of the aspirator) trigger the home safety switch. (I guess in English can be translated in "electrical leakage"...)

pat
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    Did it melt before the fuse? – TEMLIB Apr 06 '20 at 11:30
  • I'm not sure but I guess there is no fuse in there... the connection to the pins comes directly from the wall – pat Apr 06 '20 at 11:35
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    There is certainly a fuse. Maybe the two bended pins on the top-left. Could it be a lightning strike? Did you fry other appliances? – TEMLIB Apr 06 '20 at 11:38
  • "Safe" is in the mind of the beholder :-). It looks as though there are signs of a fire or similar on the other side of the PCB. It seems very likely that just rebuilding the traces will lead to whatever caused this doing it again. First it would be advisable to look at all circuitry and components and try to find the fault. Is anything burned. Is anything much lower resistance than it should be. – Russell McMahon Apr 06 '20 at 11:39
  • Maybe a short-circuit in the connector/wire harness. – TEMLIB Apr 06 '20 at 11:40
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    For sure something else is seriously wrong- to vaporize those traces requires a dead short somewhere. That needs to be located and repaired or the faulty component replaced. Maybe a pinched wire due to sloppy installation shorting to earth. – Spehro Pefhany Apr 06 '20 at 12:09
  • @TEMLIB No I guess it wasn't a lightning strike and I had no problem with other appliances. It happened by using the control (already one year ago, but I'm just fixing it now) also... at first sight doesn't seems there is any short-circuit or pinched wire. – pat Apr 06 '20 at 13:12
  • @SpehroPefhany no pinched wires at first sight, the earth cable is disconnected by installation. I read in some forum that is right, somebody even say that it is required by legal regulations. – pat Apr 06 '20 at 13:14
  • I have an idea maybe... the 3 central mechanical buttons regulate the different speed of the aspirator. I just realized that sometime the automatic (mechanic) reset of the buttons doesn't work properly. So it can happen that two of these buttons can remain in ON position. Could it be this the reason that triggered the burn? – pat Apr 06 '20 at 13:18
  • @pat Have you tried contacting the cooker hood manufacturer to get a replacement switch assembly? It might still be under guarantee, or at least a cheap part. That way, you would not have to worry about the switches sticking. – Andrew Morton Apr 06 '20 at 13:48
  • I need to rectify what I said previously... by PCB design even if two or three buttons are concurrently turned on, the current just go through one position - @AndrewMorton I'm checking... but still, if there is a problem somewhere else, just changing this component won't solve it. – pat Apr 06 '20 at 14:08
  • very good photo – Jasen Слава Україні Apr 07 '20 at 11:11
  • When it trigers gfci (or how it is named in Your country) It could be usable again when earth wire will be disconeted from the device. It's very unsafe, and everybody will shout at me, but remember that no everybody has money to buy such new stuff (and there might be possible to isolate motor from chassis, so it will be save again) – fifi_22 Jan 09 '21 at 18:15

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enter image description here

I can't be certain that that thin trace is not purposefully thin and acting as a fuse.

Jasen Слава Україні
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