[Coco] OT: electronics question

Bob theother_bob at yahoo.com
Wed May 26 01:26:33 EDT 2004

--- James Dessart <james at skwirl.ca> wrote:
> I've got a 7402 I pulled from a board. I hooked it up to a 5v source 
> and ground. When I sample the inputs, I get a lowish voltage (around 2 
> volts, unconnected pins), but when I sample the output, regardless of 
> how I drive the inputs, I get a really, really low voltage. Do I need 
> to do something in particular to drive the inputs? I'm simply using a 
> switch to vcc right now. Should I set it up with the switches 
> triggering transistors?
> It could be burned out, I used a butane torch to take it off the board. 
> It's pretty thick PCB, and I can't seem to get the chips off any other 
> way.
> James
If either input is high, the output should be low. Short both inputs to ground
and the output should go high. I assume you have the pinout for this quad NOR

The easiest method is to simply cut the leads with some small dykes, desolder
the remaining pins and solder in a socket.


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