need hepl to solve the problem

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anbudanarunm

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Hai i have to design a input selection circuit by using a matrix keypad. So i have used MM74C922 as Keypad Encoder. For testing i have assembled it in breadboard. for to verify the functionality and check the output i have used LED's at the output section. But There is no indication for the key pressing. here with this i have attached the schematics. Can anyone look in and help to figure out the problem.
 

You have to pull pin 13, output enable low to get an output.
The output pins can not source a lot of current, might not turn on the leds unless they are low current leds.
 

even after pull pin 13 to low,you find that the LEDs are not working you may further see if your bread-board is working properly (continuity test). Sometimes, the contacts will not be proper.
As a next level, think of using transistor driver circuit for the LEDs also.
 

Thanks for you reply. After including a not gate b/w pin12 and 13 now am getting the LED o/p.
 

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