I have a Jandy Aquapure 1400. I have replace the cell and the flow sensor last year. Recently it started to display an LO on the outside panel. After turning the cell off it will display service codes 145, 172 and 180 along with the LO. I went through the troubleshooting manual and got the following results.

Backboard transformer voltage 80.5 vac
Test point 2-7 = 71.5vac
Test points 3-6 = 21.4vac
Cell voltage is 0
Current test on front board test points k-h = 0 dc millivolts
Test points A-C on front board 21.4 vac
Pushing the R and Salinity buttons and the C key on the front = 2.7gpl
Pushing the R and Salinity buttons and the D key on the front = 75
Pushing the H-temp, the C key and the production up key = H-H

Based on these results I believe the front board is bad. Is this correct?
Thanks in advance for the help.