Question moved to proper eHam.net category.
My LogiKey K-3 has died. I am stuck.
Does anyone have a K-3 or K-5 that they would like to sell? Any help?
WHAT is wrong with your Logi-Key K-3 ?Schematic is on last page (page 26) of the manual.http://www.idiompress.com/K3_Manual_Tutorial.pdf
There are ONLY 2 integrated circuits in this K-3 keyer. SIMPLE Design to fix.
Freescale 68HC705C8* and 24C16http://cache.freescale.com/files/microcontrollers/doc/data_sheet/MC68HC705C8A.pdf?pspll=1
Transistors: 2N2222A (3), MPSA92
Voltage Regulator, 7805, 1A type device (7805)This device may have a heat sink, due to current draw and voltage drop.
In the newest K-5 (2004 design), they used the surface mount: NJM78L05UAhttp://www.mouser.com/ds/2/294/NJM78L00E1-196913.pdf
A transient on your +12 VDC input can damage the +5 VDC regulator.I would FIRST check with a DVM that you have +5 VDC after the regulator.