I have a ws-55819 that leaked fluid onto the green signal/control board. How do I replace this board and do I need to replace the picture tube?

It has no lamp, just the three picture tubes and they are not your problem.

I would suggest you do an inspection looking for any signs of Glycol leaks.

Each of the three tubes has a sealed area with this liquid in it, clear and very toxic.

Pull the front speaker grill off and remove the inspection plate behind it. There are three large circuit boards. Right to left as seen from the front---signal/control board green in color, Middle board tan colored----deflection/power and far left board main power and HV supply.

Leaks may be hard to see, it will not be a lot of liquid and or may appear as discoloration of parts. Leaks if there will be in first 3 inches or so of front of boards.

The green board is the most likely in your case---I will attach a photo of what it looks like and you will see the liquid on the square part on that board. The board has parts soldered to the TOP! and slight amounts may appear as discoloration of solder seen there.

As I said, you must look closely as even a tiny amount can cause real odd problems.

Let me know what you find and I will assist you.

If this helped, rate this solution as very helpful as I do this here for free.

SD TECH

Did you replace the center board with the STK-392-570 chips or the Digital convergence board mounted on it?


98% of the time if you have a convergence problem it is on the center board---the small board on the left under the metal shield box stores and controls the convergence of this set.


WHICH DID YOU REPLACE?

I am here to help----I have fixed hundreds of Mitsubishi sets with convergence troubles.

Regards, SD TECH

coolant leaks onto signal board frm crt. need to check for corrosive damage on board. to expensive to fix

No, that'll do it. Once you've changed em you'll know right away if somethin isn't right. But take faith and fire that puppy up. If the pix is good you did good. If something is amiss. I'd be happy to walk you through it. My money is on you though.

Mitsubishi - WS-55809, WS-55819, WT-46809, WS-65809, WS-65819 PCB ... try this

This set does have a lamp, it utilizes 3 picture tubes (red, green, blue) The tubes are not available as new any longer. It is recommended to replace all 3 after the reaches 5yrs of age because a new tube will over drive the others in brightness but it is possible to only replace the defective one. You can try Tritronics at 800-638-3328 for rebuilds.

You dont need a new tube. What you need is to repair the seal on your old tube and replace the CRT coolant fluid. There is a coolant chamber attached to the tube with long bolts with springs on them that contains coolant to prevent your tubes from getting hot. Yours may just need tightening, but I would replace the seal just to be safe as thecoolant can and will destroy your circuit board if its allowed to continue to leak on it.

Bad convergence ic and should replace caps also

http://home.earthlink.net/~oleg.filippov/ConvergenceFix.htm
http://cmpalmer.blogspot.com/2006/11/fixing-my-own-tv-part-ii.html

caps:
· http://www.chrisandnat.com/Projects/BlinkingTV/blink.htm · http://www.jeremyburns.com/Mitsubishi-Green-Blinking-Light-Fix.pdf
· http://www.fixya.com/howto/h159332-mitsubishi_dm_board_repair
· http://hdtvoice.com/voice/showthread.php?t=32186
replace DM

Sorry, but when the coolant leaks down onto the small signal board, that board will never work right again. The fluid penetrates the board itself since the board is double sided and has many feed-throughs. The fluid gets under the surface mount parts and just eats through the copper traces, part leads and board itself. After trying many times to clean and restore those boards, not one has ever worked right again. The boards are NLA from Mitsubishi, so the set is done.

Hello DaveDaveDave, Ok let's levelset as is said in the business world today. it looks like you have an overcurrent protection problem which means that the tv set has a component that is causing excessive current to be drawn. Now this can be caused by a component withc has become "leaky" (by leaky this means the inability to prevent the flow of electrons as related to dc voltage). Your last statement is the reason I am replying how I am. Since you don't have equipment your only option is to take this set to a TV repair shop and have it repaired. I have given you a possible cause a component in the HV section that may have gone bad, but without substantial data as to the voltage levels and signal appearances, one can only guess. I hope this helps and you find what you are looking for. Thank you, Shuttle83