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Discussion Starter · #1 ·
Hi Lads,

I have a BC LED tail/rear light fitted.

I have an intermittent problem where 4 of the tail LED's flicker as do 2 of the number plate clear LED's. The brake LED's all work as they should.

Here's a photo:



You can see that 4 red LED's, one bottom middle and 3 to the right hand side are slightly red trying to come on, the same is true of the 2 right hand clear LED's pointing downwards.

From my (limited) understanding of LED's I believe this is likely to be a faulty board, but I'm hoping somebody can tell me otherwise....... :smile2:
 

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Discussion Starter · #2 ·
Another Photo

Just to show the intermittent nature of this problem here is another photo I've just taken with the tail (red) LED's all working OK and with just the 2 clear number plate LED's flickering.



This is in fact how the problem started, it then spread to the 4 red LED's also..........

Thanks in advance for any help........
 

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From what I can see from here the printed circuit board is single-sided (copper tracks only on one side) and the component holes are rather large for the sort of components fitted. Lead diameters for those components are around 0.6mm and the holes look far too generous. On a single-sided board that can cause poor soldered joints.

On a side note, single-sided boards using conventional, not SMD components, are not the best type for high vibration duties.

I'd remove the board and look closely for a bad soldered joint. A dry joint looks like this, for example:



A fractured joint, from poor use of surplus wire cropping tools, often found on that sort of board, like this:



Check them all for cracks like these:

 

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Discussion Starter · #4 ·
Hi Forchetto,

Many thanks for such a quick response, much appreciated.

I'm only using an LED as I picked this one up cheap on eBay, but it was brand new sealed. It's British Customs light BC502-012-R, you can see it here:

http://www.british-customs.com/british-customs-plug-play-lucas-taillight-red.html

If you are correct and they are using a poor quality board that's not good at a retail price of $99.95 and that's just for the light! :surprise:

I can buy another proper (bulb) Lucas style light for small money so I may just go that way........

Thanks again for you help mate.......
 

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A properly designed board for this sort of high vibration duty ought to look like the ones manufactured by a company known as http://www.bulbsthatlast4ever.com/products/index.html

They sell mostly through another outlet, http://www.britishcyclesupply.com

See their beautifully built, double-sided, SMD component board here:

http://www.britishcyclesupply.com/Products/led/391_53454_LED.htm

The ones made by Matchlessclueless are not too bad either:

http://matchlessclueless.com/store/modern-leds/lucas-564-led-kit/
 

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Looks as if someone just got a handful of assorted components and threw them on that board...:)
They are using ordinary LEDs too. Far too narrow viewing angle. They should be the 4 contact Piranha LEDs, with a wide viewing angle, as on the second board.

The reason that I would recommend the Matcheless Clueless boards over any other is that they work on a constant current source, so are not vulnerable to changes or peaks in voltage. LEDs fed by voltage (using dropping resistors), which is the usual way, will sometimes flicker in a tail light when the bike is idling.
 

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Discussion Starter · #9 ·
OK I've now taken this apart:



And here is the back of the board:



From my untrained eye nothing jumps out as being an issue.

In anycase I've now gone back to using a bulb. The British Customs light BC502-012-R is just a straight copy of the Lucas 525 which are available in bulb format from many outlets. I had to stay with this size light as I modified an old housing to fit the BC LED version. I see Matcheless Clueless make a board for the 525 but it's a pricey item........
 

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From my untrained eye nothing jumps out as being an issue.
Use a magnifying glass or jeweller's loop. Inspect the joints where the wires solder onto the board, and all the resistor solder connections. In this board each resistor controlls an 'array' of about 3 LEDs, if the resistor goes down so does the array.

Attached is a diagram of how these boards work. It is not a diagram for your specific board, but shows the principle.

I see Matcheless Clueless make a board for the 525 but it's a pricey item........
Personally, I would not call £32.95 pricey for a LED tail/brake light board. Take your LED board for example - it is a 'Captive Lucas LED Taillight Array System' (whatever that means) from NewBonneville - price $79.95, which in our money is £54.68...

https://newbonneville.com/shop/lucas-style-led-upgrade-array/

I have a spare Matchless Clueless board for the Lusas 564 (similar shape to the 525). It is one of the first boards made. Perhaps you could convert your bulb version of the 525 to LED. Shoot me a PM if you are interested.
 

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