Electronic Control Board

Disassemble all the housings starting with front cover, top, sheetmetal side/back piece and top styrofoam support. The top slides back 3/8" before you can lift it up off the keys. Carefully pry/pop the control board loose from the top piece and swap all the wires. Had to cut loose 2 zip-ties to re-route the tank switch wires: immediately replace with new zip-tie left full loose so new wires can be re-routed without wiring bundle falling all over. Get all the wires positioned and finish tightening up the zip-ties, but not all the way, just like the factory did. Cut the tails on the ties.

While all the housings were off I vacuumed off the parts and coils and washed the fan blades off with soapy water and a sponge. Looked for chafed wires and such. Trimmed the coil case up with sheet metal shears where it was rubbing on the styrofoam bottom tray and gently filed the cut smooth.

Reassembly: snap the board back into the top piece, put the styrofoam top support on, then the side/back metal, then the top, dropping it onto the keys and sliding it forward again. The front piece goes on last.