Paul,
Thank you for suggestion. I pulled the keypad and ran diagnostic using ohm meter on key pad only. Each of the three buttons when depressed closed the loop to one of each of the three wires with the center wire seemingly to be the 'power in' wire. I surmise the key pad is good. When I depressed all three buttons however, two of the three buttons closed and the third opened. No clue what that means.
I did find an electrical short and bubble on the insulation surrounding the blue wire that runs from the control board to the Pilot Assembly for Electronic units (part # 002003F).
This blue wire is not broken, but obviously something happened that cause the insulation to overheat. I assume this is blue wire is called a High Tension wire in the Raypak parts list manual. Maybe the electrical short in this wire could have fried the control board?
I did as you suggested. I disconnected the keypad from the control board, (and disconnected the blue wire that runs to the Pilot Assembly since it has a short), then powered up... display reads the same "REM off" and then cycles to what I assume if water temp, "54 off", then back to "REM off" and so on... exactly what is was doing yesterday...
Any other suggestions appreciated!
It does peeve me that while I can buy the replacement control board and pilot assembly online, I get no warranty with the purchase. Raypak forces us garage mechanics to use their dealers. Tough choice as the total cost of parts and labor from dealer will be twice what I can buy parts directly. (Excuse the soapbox speech). In a past life, I worked on residential gas HVAC equipment, so I am not totally clueless.
Ivan