Since it's a breadboard maybe faulty connections?

Hi Lightium

Yes I think so. I have three of the same Circuit-Test MB-106 breadboards and
found that the two I have tried both have problems. I would like to know
what brand and model other people are using. Also, the little jumper wires
seem to be too loose. These boards and wires are brand new.

Thanks,

M

 

Hi maker,
Apart from the lack of power rail decoupling, it sounds as though your BB's are defective.

A point to bear in mind when using CMOS IC's, any open circuit input pin to an IC can make the circuit misbehave when you place your hands close to the open pin.
An open pin can be due to poor or total lack of electrical contact with your BB sockets, even though there may a resistor placed in an adjacent socket on the same rail.

E.
It is a pity that you are too far away to make a house call, I would like to help.

Hi E

I will keep working on this as I don't give up easily. If I was wealthy, I would fly you over
here or I would visit you. You are certainly a very kind and helpful fellow. I think that it
is too risky to buy some of these things from discount suppliers. Do you recommend a
brand / model of breadboard and jumper wires?

M

 

As far as I can see, the quality of the breadboard is excellent. I prefer to use solid 22 AWG hookup wire then I can get the proper length and colour to suit the circuit layout and not have a bowl-full of spaghetti.

 

yah, make sure your using 22 AWG wire.

 

Hi Folks:
I have received a lot of great advice and I have learned a lot. I now have all three digits working
and I am going to add the other 3. I have attached a photo of the project and I hope that it will
be of help to anyone else with an interest in this type of project.

M

 

Hi Folks:
I have received a great deal of great advice and I have learned a lot. I now have the all three
digits working and I am going to add the other 3. I have attached a photo of the project and
I hope that it will be of help to anyone else with an interest in this type of project.

M

Great, I see decoupling, bypass capacitors and clean construction. Good show!

 

Great, I see decoupling, bypass capacitors and clean construction. Good show!

Thanks nsaspook!