[Amps] LK-800A

[Will Matney <craxd1@ezwv.com>]

John,

Sorry about that. They were some manufacturers who wouldn't detail some 
circuits on schematics fearing some would copy them. Thing is, it aint 
hard to make a 555 timer so they didn't hide much. Shame it wasn't a 
Amperex timer tube the way it used to be done. Just pull its tooth and 
plug another in. There was a way though using that schematic to bypass 
the timer as it showed switching +12 on to the switching circuit. You'll 
see where the wire goes on and says + 12 V SW. Jump that to + 12 Vdc at 
the lamp connection on the ready light. Most 555's use a 5 to 9 volt 
supply so something may be open feeding the chip. If not, it could be an 
electrolytic cap, resistor, or the chip itself which really is most 
likely the case. They'll be a resistor and a capacitor forming the RC 
network hooked to the chip to set the timing. Most likely one more 
resistor from the chip to VCC. That's about all I remember on the 555 
without pulling a book.

Will



Thanks for looking guys.  The Bama site schematic is what I have and it
doesn't detail the 180 sec timer circuit and Omega wants us to send it
in for repair.  I guess I'll try reverse engineering a diagram of it and
then troubleshoot the thing.  I hate "shotgunning" parts in something
that needs a small .25 watt resistor.  It is so easy to burn a circuit
board or destroy a good part and still not fix the trouble.  I have a
feeling there were several version of this thing.  

Thanks again

John, WA5BXO
http://www.qsl.net/wa5bxo
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