MK119 Roulette

Hello,
can someone please help. My son bought this kit for christmas and I have helped him assemble it.

Although we were carefull with the polarity of the led’s we have a problem with them. When the sequance of leds run round the roulette board the sequance gets out of place. Everything is ok until it gets to here:-

19-4-21-2-6+21-36+13-6-27-13-36-11-etc

If 6 is the winner on the first pass 21 will also light.
If 6 is the winner on the second pass 21 will not light.

Led’s 25,17,34 do not light at all.

Please can anyone help.

I’m almost sure there is still a polarity problem with the leds.
If you are 100% sure (check and have somebody else check) that all the leds are correctly soldered and that there are no soldering errors such as solder bridges etc, then i must conclude that 1 or more I/O of the pic are defective (highly unlikely but possible). In that case, return pic for examination.

Thanks for the reply.

I have checked the polarity of the leds several times both visually and using a dvm. The soldering is also to a good standard

I have access to a pic programmer at work. Can this be used to check the pic. I have noticed what looks like a uv pen mark line on the top of the pic. (Not sure if this has any significance).

Are there any checks I can make using a dvm.

The mark on the pic means it has been programmed and checked.
If you are absolutely positive that there are no assembly errors then you can return the pic. A programmer or DVM is not of much use in this case.

Thinking about your advice and the fact that it is highly unlikely that the pic is at fault I de-soldered and removed the section of offending leds.

I then began replacing them one by one and checking carefully as I progressed. As I progressed I checked the sequence was working. I was able to progress without the previous problems.

The one fault I did find was a break in one of the tracks. Not sure how this happened. It may have been when I de-soldered.

However, during the process I have managed to damage 3 red leds. Can you please give me a specification of the leds so I can buy replacements? If you have a Maplin Electronics part number this would help as these are easily available in the UK.

I have managed to use alternative leds to test the circuit and am pleased that I now have a fully working circuit.

Many thanks for your time I will let you know when I am complete.

Maplin does not stock the exact same leds.
In order to protect your privacy, we have sent you an email in which we request your home address. In that way, we can send you a couple of spare leds as a one time courtesy.

Now fully working.

Well done to Velleman.