It is the Aqua Rite Electronic Chlorine Generator (XL - not that it matters

with r1.40 board.
6+ years old
Cell is only about 1 yr old
I inspected it a few days ago and it is clean as a whistle
I noticed today that, upon start-up, before the Power LED comes on the Check Cell flashes once.
I have already replaced the transistor/varistor/thingy (that everyone sites as the problem when the Power LED is off) twice because I was unsure that I got a good solder joint the first time. There was some discoloring around that component, I am now 100% sure it's correctly soldered now - did not fix the problem.
I have checked:
20-24 VAC between yellow wires, 1 on rectifier, 1 on board - good
18-33 VDC between black & red on board - good
Check transformer: measured resistance between blue & white wires and violet & gray wires they were between 2.0-2.9 Ohms which is supposed to mean that the transformer is good
***, over?
Thanks in advance.
Your pal,
-H