I recently checked out a lxi 400P heater and after the trouble shooting protocol was done, it was determined that the PIP board was bad. The home owner said that it was replaced two weeks ago by another company. I had noticed that there was corrosion on terminals and had cleaned it off to assure that there wasn't any possible short related to it before the troubleshooting test. I became suspicious that the board may have been pulled from a heater company may have replaced. I imagine that there would be a date the board was assembled somewhere on the labels on the board. the board info is as follows.
universal controller power interface
18 12
"L" 02952 Lxi4.2 chip
the info printed on board by the jva ports is 12 12 ys-2 94v-0 e226490 RoHS