Engel Fridge help sought

I’d start by taking it to Jaycar and see if they can help.

Cheers
Jim

I would remove one of the other one and test it with a multi meter.

Is there any label on the PCB that might identify its function.

There are a scattering of circuit diagrams out there but you might not find the same one but still might be able to look around that part of the circuit to give you more info.

I don't recall seeing a component like that in all my electronic life so I doubt Jaycar will know but you never know.

I think they may be a couple of ferrite beads ( L7, L8)

jaycar ferrites

The designation for L on a PCB is generally "Coil, Inductor, Bead, Ferrite Bead". To me it looks like an RF inductor wound ferrite bead. When you say you shorted it and it works are you referring to bridging across the top of the two coil looking bits?

De solder it and have a look from the bottom I think you will find a wire enters it (maybe has some loops internally) then passes out to the next one.

David

William

Good on you for having a go and disassembling the power pack. They aren't easy to get apart.
I have been playing around with an MT45 which became defunct as many of them do. On my board, (looks the same) those 4 similar units are simply a wire through a two ferrite beads on each one. That one in particular feed the negative line to the CATHODE of the RH side 15A ZENER diode in the circle background. I would simply solder a piece of fuse wire, 10amp perhaps across the ferrite tops or replace the item with a fusible device of some nature.

The brownish red device above the large black 15A ZENER diodes is a fuse of 5 Amp. there should be two of those , one is hidden in amongst the Electrolytic capacitors.

My guess is, someone reversed polarity on the feed line and the large ZENERs passed enough current to blow the top off the link. It would melt to save the MosFETS on the heat sink.

Let us know if it goes again. Those boards are very expensive. There must be quite a few Engels around which have minor electronic faults but don't run.

EDIT, Anode changed to cathode, made a mistake, I had my electrons Frack to Bunt.

.William,
The device you circled is indeed a pair of ferrite beads, cylindrical form. They are arranged as a pair of ferrites with a conductor rising through one then looping back to the circuit board through the other. I can see four such sets in your photo. Their purpose is to eliminate high frequency electrical 'noise' in the circuit.

The one that has "blown" is simply the wire link that passes through the ferrites and would be the result of excessive current. The cause of this excessive current can only be guessed at but may be because of a failed electronic component although it must have been pretty significant to fuse the link of substantial current carrying capacity. It could also have been caused by some conductor coming into contact with the link.

You say that the compressor runs when the blown link is bridged so that is a hopeful sign. You could try replacing the blown link with a piece of suitable copper wire by re-soldering on the underside of the board. Wire size is not critical and you could gauge from the intact nearby links. However I would not guarantee success considering the excessive current that must have passed in the circuit but I do wish you good luck.

William
If the fridge has a ciggy plug end on the cable, ie, the one which is grey and has a fluted body, check to make sure it hasn't been unscrewed and the pins placed back into the body the wrong way, ie WRONG POLARITY supplied to fridge cable. I have one of those type and see it as a problem IF ever taken apart. If it is wrong then it explains the link fused/melted in the fridge.

Hi guys!
I read this thread with interest and thought to myself "Now this is what our site is all about, help with no slanging matches"
Well done everyone!

Hello again,

Thank you every one for all the valuable information.

I have repaired the circuit board with help from the contributors on this site.

Currently the fridge is working well, currently sitting on -15.

I am very happy, for a little bit of time, some scrap wire and with my dodgy soldering skills this fridge is working, I'll leave it run for a while.
I don't think I will use it as my main fridge as I have 1 other and my faithful Bushman.

Photos attached of my repair, it is pretty good considering my soldering iron and lack of skill.

William