Outdoor wall light issue

[Flyingdogguitar]

Hi,
Very new to electronics guys. So please be gentle with me!
Managed to repair an outdoor Luxform LED light. But this was short lived, as it looks as if the back of the circuit board which measures only about an inch square. Has shorted itself out on a part of the light structure itself, blast!!!!!
How difficult would it be for a novice like myself to construct a new circuit board? This wall light isn't made anymore. So, I know have one light that works on one wall. And one that doesn't on the other!

Yours hopefully
Dave (Essex - the place NOT the person)

 

[DerStrom8]

Could we see a picture of the board please? Preferably a top-and-bottom view.

 

[Flyingdogguitar]

here we go!

 

[alec_t]

Unfortunately the second pic is rather blurred. What ID is marked on that square black component top left of pic? What markings are on the black component (looks like a diode) at bottom left?

 

[Flyingdogguitar]

Hi, I'm out at the moment. I'll have a look when I get home

Regards
Dave

 

[Flyingdogguitar]

Hope this is better?

 

[Flyingdogguitar]

Another couple of pics showing where I think the board has shorted?

 

[DerStrom8]

I don't know about shorted, but it does look like it got wet and corroded some of the contacts and traces.

 

[Flyingdogguitar]

Is there anything I can do?

 

[cowboybob]

Try running insulated 18 or 20ga jumpers where the red lines are in the snip below, to replace what appears to be blown (or corroded) traces.

CAUTION: make absolutely certain that there is NO POWER to the board when you attempt this repair. If you do not know how to assure yourself of the electrical safety of the repair, do not try it.

This repair might not fix the problem since there's no assurance of what damaged the traces in the first place.

But it looks to me as though the trace damage was most likely "short" related. Let's hope it was mechanical and not component related.

 

[alec_t]

The white wire end shown in post #6 has loose/broken strands which could have shorted somewhere. Tidy up the connection.
The insulation on the brown (live) wire is dented. Make sure there is no metal showing through it. Replace if doubtful.
If the suggestions don't get it working and you have a multimeter, you could disconnect the 'good' light and compare resistance values of its components against those of the faulty light to identify any fried component.

 

[Flyingdogguitar]

Success!!!

 

[alec_t]

Well done! We always like a success story.

 

[Flyingdogguitar]

Thanks for the help. Although I won't show you my soldering, as it's quite amateurish.

Dave

 

[KeepItSimpleStupid]

What's your mains voltage and where about (continent is OK)? You might want to add a MOV across the line and fuse in series with the line.

 

[Flyingdogguitar]

Hi, it's 240 volt. And I'm just outside London.

By the way, what's an MOV?

Dave

 

[KeepItSimpleStupid]

So, something like this https://uk.farnell.com/fairchild-se...-300v-1500w-axl-bidirc/dp/1700749?Ntt=1700749 will work.

It's a bidirectional TVS or Transient Voltage Suppressor.
MOV's (Metal Oxide Varistor), ZNR's (Varistor) and TVS (Transient Voltage Suppressor) all fall into the same category of a device that limits surges.

The fuse is up to you. A physical 5x20mm might work well. Size it as 2x the load. If you don;t know the load, guess or measure. You may have the number of Watts someplace, so you can back that out.

1 Amp would be 240 W and that's probably too big,

The PC trace acted as a fuse and when you replace it with a wire of a larger cross-sectional area you lost that as an ersatz "fuse". So, I'm saying a fuse and and some sort of transient voltage suppressor would not hurt.

The lights look pretty cool BTW.

 

[cowboybob]

Good advice, KISS.

You could see the teeny metal globules at the edge of one of the traces that indicated the "fuse" action of the trace.