Sony FWD-46B2 - two blinks on front, continual blinks on mainboard

Howdy, all,

I inherited a Sony FWD-46B2 monitor from work a few months ago, and am only now getting to work on it. The main issue is plugging it in and powering it on, which makes the screen blink on very briefly (perhaps 1/15th of a second?) before showing two red blinks on the front of the unit.

I’ve already replaced the power supply and mainboard (separately, not together) and with either component, I get the two-blink issue. Additionally, I’ve noticed that the mainboard continuously blinks red until the TV goes into two-blink mode.

Should I go ahead and replace the power supply in conjunction with the mainboard, or is there another component I’m missing?