when relay boards go bad.... Options

[type47]

got a chance to do some work on the teener today. plans were to weld (IMG:style_emoticons/default/welder.gif) in a bung for an O2 sensor for LM-1. rod (root) was going to do some tig work on the bung. problems with car on the way to his shop. car quit twice. i carry a pressure gauge so i connected it on the cold start valve port and got zero pressure. simple i thought, bad fuel pump. even connected a voltmeter to the fuel pump power plug to verify voltage to the pump. however, didn't see that voltage was 12 mV not 12 V (where are my glasses...). long story short, i was able to get to rods shop and, third times a charm, bung got welded in (by the way, this may be a "DUH" to many but don't try to weld in the bung with the plug screwed into the bung, it'll just seize the plug. i/we didn't know any better). attempt to start the car to go home, no start. no pressure then we observe 12milliVolts at the pump connector. rod says all signs are pointing to a bad relay board and graciously lends me his relay board to get me home (IMG:style_emoticons/default/smilie_pokal.gif) so now my question is: how often/frequent do these fail and would like to hear some experiences about how the faulty board was discovered. it's hard for me to believe the board failed and i'm going to do some continuity tests on it. to me, all signs led to a bad fuel pump.