Light Chaser, DUD Kit!!

WBahn

Joined Mar 31, 2012
30,081
Kit for doing... what?

Hard to look for why something doesn't do what it's supposed to do unless we have a clue about what it's supposed to do?
 

Ramussons

Joined May 3, 2013
1,414
It is a simple Light Chaser using 2 SR's and a 555.
Either the power supply is not able to supply enough current or, there is a manufacturing defect of the LED's being wired the wrong way.
 

Alec_t

Joined Sep 17, 2013
14,335
From the schematic it looks as though the reset state results in all LEDs on. Is that what your first pic is showing?
It also looks as though SW2 is for 'chase start' and SW1 is for 'chase stop', or for selecting whether 1 or 0 is circulating. Is that the intention?
 
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Thread Starter

Icanmakeit67

Joined Sep 23, 2018
97
It is a simple Light Chaser using 2 SR's and a 555.
Either the power supply is not able to supply enough current or, there is a manufacturing defect of the LED's being wired the wrong way.
I have not tried any LEDs except those provided. I did test a couple to see what they looked like ON. I have one more unbuilt kit. I can try different LEDs.
 

Thread Starter

Icanmakeit67

Joined Sep 23, 2018
97
What test equipment do you have access to? Do you have a DMM? Have you made any measurements on the circuit?
Yes I have a meter. I have means to check the ICs( all ok) pot ok, random selection of LEDs worked ok, I followed schematic and PCB seems to be correct. No broken traces. Correct power. Buttons work properly. I even built last of three attempts with IC sockets, not plugging in ICs until ready for power. So…..I’m open to any ideas(what measurements do you suggest?) I’m not an engineer so theory issues you all might see problems with? This by the way is a kit sold often and available in several places so WTF!!??
 

ElectricSpidey

Joined Dec 2, 2017
2,786
Carefully remove the 3 chips from one of the kits you assembled with the sockets.

Take a piece of breadboard and place the negative lead from your supply to one of the buses, place a low value resistor (100 ohms or so) from the bus to an open slot, place a length of solid wire into that slot. (the idea here is to create a negative probe with a resistor in series.

Connect the positive lead from the kit to the supply positive.

Set the supply to 5 volts.

Probe the pins on either of the 2 shift registers that connect to an LED.

Post the results. Next steps will follow.
 

Thread Starter

Icanmakeit67

Joined Sep 23, 2018
97
But do any work after assembly? Is the assembled LED polarity correct?
The kit after assembly does absolutely nothing. I have used clips to attach a couple LEDs in the reverse polarity of what’s shown but nothing. It may be because the original LEDs are attached. If you look at the schematic/PCB board the connection points match the design in red to polarity…. I’m going to build one with LEDs from my own stock but leaning towards low odds of making a difference
 
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