Hey,
I'm trying to get my circuit to work. I was given a working schematic and designed the PCB in ulitboard so i believe the design of my circuit is correct. However when I soldiered r everything together and tested it only LED number 1 comes on and stays on but the LEDs are meant to come one one by one. I checked all my solider joints and think they are fine. any suggestions would be great. thanks

 

Check the group of three copper traces that run parallel to each other on the bottom of the board, right side running horizontal on your photo. It looks like you may have a mess of un-etched copper connecting all of them together. Either that or a weird reflection in the photo.

Other than that, I did not bother to check if all of your connections are correct. But one thing is for sure, you need to clip the long leads on the back of the board to make sure they are not shorting each other.

The other possibility is that the 555 does not go low enough (close enough to zero volts) to trigger the 4017.

Good luck.

 

welcome to debugging!

the checklist I live by for the first 5 things-
1, is it plugged in
2, are all chips in the sockets
3, are all chips the correct orientation
4, are they the correct chips
5, repeat 2-4 for all transistors

solves 90% of my issues, no joke

after that start chasing traces, check each pin of each chip first and make sure it's doing what is expected of it

do you have access to a scope?

 

How do you reset the 4017 chip?



Edit: Oh, so the IC start all over when one cycle is done...

Attached is one setup I used for a project. With this you could add 2 more LEDS and connect PIN 6 to PIN 15. When the circuit is running, and the IC has reach LED 6 on PIN 1, it resets itself to start over.

Also, as mentioned, check the horizontal traces with a DMM.

 

hi ram,
If the 555 is not running the 4017 will remain on pin #3, [LED1].

Connect a test LED on pin 3 of the 555, it should flash, if not the problem is with the 555 connections.

Also as suggested previously, first crop off those excess component wires.

E

 

Crop all the soldering, and it looks as pins 14(clock), 15(reset) maybe shorting out, which will keep resetting the counter to put the first led on.

 

Hello ram4461

There are several things to improve in your circuit:

Remove resistor R15 connected from the PIN 3 at 555 till the PIN 14 of 4017. is not necessary, in its place install a jumper.

probably also have problems with MR PIN entry in the 4017 14.
resistor R16 has a very high value (100K) could be replaced by a 10K. resistor.

you have to analyze the data sheets of both the transistor and the LED you use in your circuit to determine the value of all the necessary resistors for the LED lights.

To the transistor are of particular importance Ib and VCE (sat) parameters.
For the LED are particularly important parameters Vf and If.

 

Some of the traces in the top right section of the second pic appear to be discontinuous/ etched away ? Or is that just an artifact of the pic?

 

C3 and R16 are not needed. Master reset can be tied directly to ground.