Hi maker,
Did you use a LED probe to check the voltages that should be present on the 100' counter as compared to the 10's counter.
You may have a defective bread board???

E

 

Hello,

Did you try to build the counter on other rows of the breadboard?
As @ericgibbs said, there may be a defect in the board.

Bertus

 

Hi:

Checked them. Pins are ok. I have checked the wiring multiple times and even re-wired multiple times.

That is another mistake. Don't rewire a circuit until you find the fault. This is how you learn to diagnose a problem and learn from your mistakes. Every failed circuit is an opportunity to learn something.

You may have a faulty breadboard. An oscilloscope is an essential tool for this kind of diagnostic work. If you don't have an oscilloscope, use your DMM, not the LED probe. Test the voltage at the pin leading into the IC package, not at the hole beside the pin in the breadboard.

 

Check that you actually have 0V on pin 1 of the third 4510, at the pin, as MrChips suggests. It sounds as if you're stuck in Preset mode!

 

A logic probe, if you have one and provided you know what expect in every pin, using a slow clock could help you while really learning in the process.

 

That is another mistake. Don't rewire a circuit until you find the fault. This is how you learn to diagnose a problem and learn from your mistakes. Every failed circuit is an opportunity to learn something.

You may have a faulty breadboard. An oscilloscope is an essential tool for this kind of diagnostic work. If you don't have an oscilloscope, use your DMM, not the LED probe. Test the voltage at the pin leading into the IC package, not at the hole beside the pin in the breadboard.

Bertus, Eric & MrChips:

I checked the voltages on the segment output pins and they all have 5 volts.

I found that part of the breadboard is defective, where I previously had the
display. I also have 2 more new Circuit-Test MB-106 breadboards but they
may be garbage as well so I don't know if I should even bother to try another
breadboard of the same kind. These boards were purchased from Sayal Electronics
in Toronto, maybe there stuff is poor quality. Thoughts?

Check that you actually have 0V on pin 1 of the third 4510, at the pin, as MrChips suggests. It sounds as if you're stuck in Preset mode!

Pin 1 of each counter is wired to ground.

 

That is another mistake. Don't rewire a circuit until you find the fault. This is how you learn to diagnose a problem and learn from your mistakes. Every failed circuit is an opportunity to learn something.

You may have a faulty breadboard. An oscilloscope is an essential tool for this kind of diagnostic work. If you don't have an oscilloscope, use your DMM, not the LED probe. Test the voltage at the pin leading into the IC package, not at the hole beside the pin in the breadboard.

OK. Checked the pins not the holes. My scope only goes down to 10 Hz.

 

hi maker
Is the bottom half of that left side BB OK as far as you know, if yes, just move the logic IC's down to that lower half.
That's what I would do to prove a design.
E

 

OK. Checked the pins not the holes.

hi maker
Is the bottom half of that left side BB OK as far as you know, if yes, just move the logic IC's down to that lower half.
That's what I would do to prove a design.
E

hi E
I will try that now. Thanks.

 

Hi,
How are the BB's secured to that Base plate?
E

 

Hi,
How are the BB's secured to that Base plate?
E

Hi E
They are screwed on. I wish I had thought of that before I started re-building the circuit on
a different board. Thanks so much for thinking of that. I guess that's why you are an engineer
and I am not.

M

 

Solderless breadboards should come with sticky foam backing. If you are mounting the breadboards on metal I would add a layer of thick mylar film to prevent shorting on a metal base even if the metal is painted.

 

Solderless breadboards should come with sticky foam backing. If you are mounting the breadboards on metal I would add a layer of thick mylar film to prevent shorting on a metal base even if the metal is painted.

These are prefabricated from Sayal. I suspect their stuff is garbage that was rejected in
someone's QC dept. Actually, their jumper wires are pretty sloppy too. I have re-wired the
first stage on a new board. I checked the wiring. It counts and displays 0 to 7. Then next thing
it stops counting. Then I power up again and it counts 0 to 1 over and over. There are no
wiring errors. These are the same chips that were working in stage one previously.
This is nuts, now if I wiggle the wires the 0 to 9 thing works. After a while it just
stops counting and displays a zero. What should I do?

 

This is a long shot but I don't see any power supply decoupling capacitors on your board.

1) Where power enters the board, place a 10-100μF (around 25V) electrolytic capacitor across Vcc and GND. Make sure the -ve lead goes to GND.

2) Across every bus rail, place 0.1μF ceramic capacitors across Vcc and GND.

Your CD4013 IC is missing GND connection on pin-7.

 

This is a long shot but I don't see any power supply decoupling capacitors on your board.

1) Where power enters the board, place a 10-100μF (around 25V) electrolytic capacitor across Vcc and GND. Make sure the -ve lead goes to GND.

2) Across every bus rail, place 0.1μF ceramic capacitors across Vcc and GND.

Your CD4013 IC is missing GND connection on pin-7.


View attachment 315421

Hi:

This is a photo of my original circuit that worked for 0 to 9 count. In my re-build, I have grounded
pin #7 of the CD4013. Don't know why it worked before without pin #7 grounded. I will add the
capacitors and let you know what happens.

I did everything that you suggested. The circuit counts from 0 to 7. There is a problem because
segment "d" doesn't always light up when it should. A good deal of the time the thing doesn't
even count at all when I power up, it just displays a zero. I am worse off than I was a week ago.
The wiring is definitely correct. I think that these breadboards are garbage as well as the jumpers.
Sometimes if I press on the board the circuit behaviour changes.

 

Hi:

This is a photo of my original circuit that worked for 0 to 9 count. In my re-build, I have grounded
pin #7 of the CD4013. Don't know why it worked before without pin #7 grounded. I will add the
capacitors and let you know what happens.

I did everything that you suggested. The circuit counts from 0 to 7. There is a problem because
segment "d" doesn't always light up when it should. A good deal of the time the thing doesn't
even count at all when I power up, it just displays a zero. I am worse off than I was a week ago.
The wiring is definitely correct. I think that these breadboards are garbage as well as the jumpers.

I know that it is frustrating when things that are supposed to work don't fly.
Again, my advice would be to not give up, persevere. Don't rip up the circuit and start over.

I am going to say it again. Every failed circuit is an opportunity to hone your trouble shooting skills.
If your goal is to expand your knowledge and enjoyment in electronics then you need to acquire the right tools and skill set.

In this particular situation, you need to find the fault because if you try to brush it under the rug it will come back to haunt you.
The way I would approach this would be to increase the CLOCK frequency to greater than 100Hz or more. Then use an oscilloscope to see what is actually failing. Ok, you don't have an oscilloscope. Even at this stage of your adventure, a DSO138 is still better than none. Later, when you acquire more experience you will be in a better position to choose for yourself either a used or a new better oscilloscope. (Don't buy a DSO138 DIY kit that needs to be assembled. Get one that has already been assembled and tested.) If you want to spend more money there are other options.



Give it a thought.

 

I know that it is frustrating when things that are supposed to work don't fly.
Again, my advice would be to not give up, persevere. Don't rip up the circuit and start over.

I am going to say it again. Every failed circuit is an opportunity to hone your trouble shooting skills.
If your goal is to expand your knowledge and enjoyment in electronics then you need to acquire the right tools and skill set.

In this particular situation, you need to find the fault because if you try to brush it under the rug it will come back to haunt you.
The way I would approach this would be to increase the CLOCK frequency to greater than 100Hz or more. Then use an oscilloscope to see what is actually failing. Ok, you don't have an oscilloscope. Even at this stage of your adventure, a DSO138 is still better than none. Later, when you acquire more experience you will be in a better position to choose for yourself either a used or a new better oscilloscope. (Don't buy a DSO138 DIY kit that needs to be assembled. Get one that has already been assembled and tested.) If you want to spend more money there are other options.

View attachment 315430

Give it a thought.

I have a new Siglent 1104X-4 four channel digital storage scope but apparently it only goes down to 10Hz.
I wouldn't know what to look for.

When I press on the circuit board the circuit behaviour changes. How is it ever going to work?
This is the second of three boards that I have tried.

 

Shucks. If you have a new Siglent 1104X-4 have you taken it out of the box yet? What are you waiting for then?

Oscilloscopes can go below 1Hz. In any case, why do you need to go below 10Hz? I said go up to 100Hz or higher, even 100kHz then you don’t have to wait all day to see changes.

 

Since it's a breadboard maybe faulty connections?

 

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.