Hello Dear Forum Members,
I recently bought and built 18 MK100 Christmas Trees as presents for family and friends.
All but one tree works exactly as they should. The one that doesn’t work as it should has the following symptoms;
LEDs 1, 3, 5, 7, 11, 13, 15 are flashing
LEDs 2, 4, 14, 16 are on but NOT flashing
LEDs 6, 8, 10, 12 are not on at all.
Looking at the circuit diagram supplied with the trees it is easy to see that all LEDs on the left hand side of the diagram have problems and the LEDs on the right hand side of the circuit are working as they should.
As I have no test equipment here is what I have done to try and resolve the problem;
Thinking C1 could be the problem – I replaced it with a new one – Result = No Change
Soldered the original C1 back on
Replaced C2 with a new one – Result = No Change
Soldered the original C2 back on
I thought, surely it must be T1 or T2 causing the problems?
I replaced T1 with a new BC 547B – Result = No Change – left the new transistor in place
It had to be T2? – I replaced T2 with a new BC 547B – Result = No change - left the new transistor in place.
Highly unlikely to be a resistor problem?
I have checked the polarity of each LED and they are all correct – I am at a loss now. I don’t mind just scrapping this tree, I realise it doesn’t cost much, but I am eager to learn as to why this could be happening I would love to be able to find the fault. Any suggestions would be much welcome.
Thanking any and all replies in advance.