I've replaced every board on the samsung plasma and still clicks

Replace it and check. If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/

Do yourself a big favor and just replace the TV, replacing parts is just to costly and in most cases it doesn't fix the problem.

Have you tried replacing the power cord or the voltage feed may be off replacing the whole cord should correct that

recheck first the wiring, if ok check bad component parts at the buffer board.

Take your scope and see if you have any activity on the LVDS cable on the main digital board as you press the menu button or the menu on the remote. If you do not see anything then replace the main board. If you do then the plasma display panel is probably bad. Time for the bone yard.

Something is wrong with your logic board, you've got the option of returning this TV if it's still under warranty or buying a new one.

Hello,

The ysus board is the most common reason.you have to replace the board, you can check on shopjimmy.com, ebay.com for replacement.Thanks and Take care

yep, do u have a digital multimeter? if so, measure all the voltages from the power board located top middle. if u look at the top right of the panel, there is a sticker with va, ve, vset, vsc settings. ground the black lead, and use the red lead to read each of the settings on the pow bd. if there are more than 2 mismatches, its your power board and needs replaced.

Try the following steps:
1. Remove the power supply to X Main board, check VE. If you get normal VE then replace the X Main board. Otherwise to 2.
2. Remove the power supply to Y Main board, check VE. If you get VE then replace the Y Main board, otherwise to 3.
3. Replace the SMPS board & SMPS 200V board.

Good Luck