My Akai PT5598HDI has developed a blue shadow or ghosting around white colored objects. I purchased it late in 2004. The picture is a little better if I turn the contrast down to zero, but that makes for poor picture quality. I am an electronic technician so I possibly can perform most repairs myself. Just need ideas or direction to follow.
Thanks, Jim Nelson
mailto:[email protected]
If the ghosting is like a 3D effect its your convergence ICs , but if its like a blue Halo around objects that usually means your CRT coolant has congealed and will need replacement. The blue is the first tube to congeal for some reason, followed by green. Red seems to be not quite as prone to this. It is a normal occurrence n sets about 4 years old to need the coolant changed.
If you would like instructions on how to change the coolant let me know .
Okay you have to remove the blue crt. First and most important is to remove the HV Lead from the HV block and then ground that lead to the chassis to discharge the CRT. The lead has to remain in the Tube. Next label the Yoke plug connections where you unplug them from the chassis. The yoke and purity rings have to stay on the picture tube. Then remove the PC board from the end of the picture tube. There will be at least one or two ground wires running from the tube pc Board up to the shield on the tube. Disconnect those. Then there will be 4 small screws holding the picture tube assembly into its mount. Remove them and lift the tube up and out of its mount. Be careful not to bump the tube or purity rings while removing it. Most tubes have a plug that is removed to gain access to the coolant chamber between the tube face and lens assembly. Remove the plug and pour the coolant into a pan and discard. After the coolant is out it is best to loosen the bolts with the springs in an alternating pattern and remove the coolant chamber form the tube face so you can clean the tube and chamber with alcohol. Dry it good. Them reassemble the coolant chamber by alternately tightening the bolts with springs until secure. Then fill the chamber with new coolant and reinstall picture tube in its mount. That's about all there is to it. It takes probably an hour to remove the tube and put it back in. just take your time and label any wires you remove. I will post a link to where you can purchase the coolant. Let me know if you need any additional info.
http://www.matelectronics.com/cgi-bin/ss...
Good to hear your set is back in top operating condition. The coolant definatly makes a big difference.Glad that I could assist you.
×
299 views
Usually answered in minutes!
The blue halo around objects sounds like the problem. People with black hair usually appears with a bluish tint. All three colors appear very good. Can I request instructions on how to replace this coolant and where is the best place to get this fluid. Thank you very much for your help so far.
You nailed it. I just received the CRT coolant on Friday, followed your instructions verbatim and my projection TV now looks better than new. The old coolant in the blue and green tube tank was a dark yellowish color with a slime built up on the tube face. I used alcohol and cleaned all three tubes and replaced with new clear coolant. With a little manual convergence it now has vibrant colors and looks great again. Thanks for your help.
Jim Nelson
×