Question about Akai PTH5498 54" Rear Projection HDTV-Ready Television

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Blurry picture & no sensor data in blue convergence

Tv used to have a great picture. Now it's a little blurry and the colors are never right. When I try and do a convergance NO SENSOR DATA shows up for blue. The red seems to work ok. Last summer had lighting strike the house and got several eletrical appliances. Thjis didn't show up before the lighting strike but sometime after.

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6 Suggested Answers

6ya6ya
  • 2 Answers

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Posted on Jan 02, 2017

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tvtechnician
  • 105 Answers

SOURCE: Sony KP-48S65 48 in. Rear Projection: fine tune convergence

you will have to go in the service mode. be careful as you could damage the tv if wrong settings are changed. with the tv off push on the remote display 5 vol+ power. now hit the 1 button until you see pje fdis on the upper left. now push the 9 button to enter convergence. you should now have a cursor on the screen. usr the 3 button to switch colors. use the directional pad on remote to move the cursor and the enter button in the center of dir pad to select or deselct a point in the screen. push muting and then enter to save convergence. now restart the tv and all done

Posted on Oct 13, 2007

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Shmoopy
  • 53 Answers

SOURCE: Akai PT4298HD Rear Projection

Perfect Focus and the convergence screen are for convergence, not actual focus. Real focusing is done in a combination of two ways: electrostatic and optical. And to do it right you need a good test pattern, like the convergence pattern from the Digital Video Essentials DVD. At a bare minimum turn your contrast down to half (don't use "dynamic" mode, ever).

This is going to sound scary, cuz it terrified me at first but now I'm comfortable with it:

To focus electrostatically, the front panel under the speakers needs to come off. As in actually unscrewing some screws and opening up your tv. Do all of this without cats or toddlers in the room. There are three circuit boards on which the picture tubes are mounted, and each board has a focusing knob next to the words "red," "green," and "blue." Do not touch ANYTHING other than these knobs. Twist the focus back and forth until it is as focused as it will get. The lines on the convergence pattern will get fatter or skinnier. If they get fat in one direction and skinny in the other, find the best compromise. Do not focus the blue too perfectly, as perfectly focused blue lessens the amount of blue relative to the other colors, making whites look yellowish.

Next you really need to clean your lenses, they are filthy from dust and that's why the focusing is so bad. For this tv, you'll want all three panels on the front to come off. That's about twenty screws, both on the sides of the tv and the undersides of the panels. The middle panel that covers the speakers can rest on the floor by the front panel, but the screen panel needs a resting place. An ottoman, or a chair with a towel on it, makes a good place to rest the screen (parallel to the floor).

Each CRT has a set of focusing lenses, and these can be removed. Do one at a time. They come off from four screws each. FOUR SCREWS. Do NOT unscrew anything else, as just under the lenses is a cover for the CRT. Take this off and you risk coolant leak, leading to expensive electrical problems. Do not, repeat, NOT touch either the lenses or the mirror with your fingers. One scratch is bad. Scuff marks can destroy a picture. These lenses and mirror are easily damaged.

http://www.keohi.com/keohihdtv/learnabout/generaltips/screenoptics.html

There are some cleaning techniques there. I'd only bother cleaning the top and bottom of the lens assembly. Don't mess with the wingnut on the side, we'll handle that later.

Now, with your CRT lenses back on (wingnut facing towards the mirror), replace all of the panels and rescrew the screws. Next we do optical focusing. Again, this is where test patterns from a test pattern DVD come in handy. Regardless of what TV a person owns, a DVD like Digital Video Essentials is, well, essential.

This time we're taking a panel off the *back* of the TV. Scary, huh? Specifically, the bottom one (there are two big back panels). About fifteen screws, four of which are the same ones you do to get the front bottom panel off. Get all of the screws off, pull it back, and lift it out. Don't touch any of the electrical stuff. From here, if you are careful, you can reach up under the mirror and untighten the wingnuts on each CRT lens assembly. If you are using a test pattern, use a standard definition one here, makes the scanlines easier to see.

Here's what I do to focus each gun:
1) Put on a full screen of green, red, or blue, depending on which gun I'm focusing. DVE has just these patterns.
2) Untighten the wingnut, and start making minute adjustments.
3) What you want to see is *scanlines*, as clearly as possible. Make a tiny adjustment, get back around to the front of the tv, and see how well you can make out scanlines. An all-green screen should actually be a bunch of horizontal lines of green. If you can't make out these lines, you aren't focused.
4) If you don't seem to be making progress at all, switch to DVE's convergence pattern to make sure you haven't completely lost focus on that color. You want to start from good focus, and then fine tune very delicately.
5) You may find it hard to get blue-focus perfect. That's okay, really, as blue is a filler color. Green was very hard for me to see lines on, but it was a step up from not being able to see them at all.
6) You may find it necessary to go back and forth between electrostatic focusing and optical focusing adjustments to get them right. That's okay.
7) When it seems you've done the best you can, you're done. Put the back panel back on and rescrew all of the screws.

Now you need to adjust your convergence. You can use the user convergence menu, but it will only get you halfway there, because it only controls like nine or twelve points. What you want is to access the *service* convergence menu. With the tv on, press mute-1-8-3 on your remote (not pressing them all down, just in that sequence). You should switch to a secret built-in convergence screen.

I hate to tell you this, but the only way to save settings made in the service convergence screen that I know of is with a Samsung remote, not the Akai one. This tv is actually a Samsung after all, and the Akai remote is missing some buttons that the Samsung remote has. You can buy them off partstore.com, among other places. Here are what the buttons do:

7-allows you to control red convergence
8-allows you to control green convergence (what the screen defaults to)
9-allows you to control blue convergence
+100-turns red on or off
0-turns green on or off
pre-ch-turns blue on or off
circular direction buttons-moves the cursor to a new convergence point
channel up/down-moves the convergence up or down
volume up/down-moves the convergence left or right

ONLY ON THE SAMSUNG REMOTE:
add/erase-saves settings after blinking the screen and centering the cursor

If you can find a button on the Akai remote that does that, you won't need to buy a Samsung remote.

BTW, you'll want to do this service convergence on each scan rate. So one for 480p (from a progressive scan DVD player), once for 480i (s-video source or non-progressive DVD player), and once for HD (I use my HD DVD copy of DVE).

Posted on Mar 19, 2008

easyab
  • 132 Answers

SOURCE: Samsung Rear Projection Problem (not convergence)

The tv has 2 focus adjustments for each tube, mechanical and electrical.

1. Mechanical focus is set by looking at screen from back (through inspection plate on back of most samsungs) and rotating the lens assembly on CRT. loosen wing nut and turn lens assembly to go through focus and back to best position.

Put convergence pattern on screen and manually misadjust bottom red and green lines convergence so they can be seen through inspection hole.

With back cover of TV off you can usually reach your hand up beside the lens assembly to loosen the wing nut then rotate to adjust. Green is in the middle. The focus will be obvious when you rotate and look

When you are finished make sure the foam dust protector is not over any of the lens assemblies and the wing nut is tight.

2. Electrical focus - located at front of unit. the front grille/speaker cover is removed and maybe a cover over the front crt inspection hole.

In the inspection hole there is a black plastic "Focus/screen adjust Assembly" with 2 rows of 3 controls.

One row is focus and the other is screen. The middle controls are for green with R/B on either side. Usually the controls are labelled as "focus" and "screen". You want to adjust the focus controls, one for each color. Look for the focus or screen label imprinted in the plastic. Don't play with the screen settings.

With the same misadjusted convergence pattern you can see a red, blue and green line. Adjust green focus and watch green line for best focus. Do same for other 2.

Screen adjustments are very exact and delicate. The easiest way to deal with them is to turn color off in Customer adjust menu. Put any color tone adjustments in the middle (low, med, high, put at med).

You should have a b/w picture if there are no crt or other color related faults. If it is close to B/W leave screens alone.

If the pix is too green, then the green screen setting must be reduced a small amount. Do not play with these adjustments as most TV repairrers have a difficult time adjusting them.

If focus adjustments don't help then focus control or CRT may be defective. Needs expert to determine.

easyab

http://calgaryconvergencerepair.weebly.com/convergence-ics.html


Posted on Jun 25, 2008

SD Tech
  • 14553 Answers

SOURCE: Convergence comes and goes.

OK, THIS model uses two STK-392-110 convergence IC's--if hitting the set makes the convergence come back you may have bad solder connnections on them====each has 18 pins--considering the labor just to get at them to solder them---i would replace both anyway, even if I find bad connections on them---one of the reasons they fail is the back of each is metal and a white grease to transfer heat to the metal they are attached to dries out---this set is old enough the grease is now probably dry--YOU CAN BUY BOTH IC'S FOR LESS THEN 13 DOLLARS ON EBAY PLUS SHIPPING----Not a do it yourself job if you do not have certain skills---shop around in your area---here I do this in home for people for 200-250 depending on the set----shops get 3-4 hundred and some do not do it in the home---I don't have to tell you the economy is poor right now; and this time of year is the slow time for most tv repair shops---find someone who has done this kind of repair on your brand of set--a good tech can do it in about an hour right in your home---200-250 is a good price--you cannot replace the set for this kind of money.

these sets are much more dependable then LCD or Plasma TV sets--not one of those sets get fixed in the home--and 80% of them that come into the shop I work for are less than 2 years old--if you buy one get a 3 year warranty.

If this has been helpful give me a vote here--I do this for free--you need help or have any questions:

etower.766@netzero.net

Posted on Aug 24, 2009

Testimonial: "etower, thank you very much. Extremely knowledgeable, precise, explained it very well. Thank you so much. "

SD Tech
  • 14553 Answers

SOURCE: Hitachi 53UWX10BA dynamic convergence works but blue is blurry

I know this set very well---you are saying convergence adjusts ok everywhere? If you understand that the blue is usually de-focused a little----there are only two ways to adjust the focus of each tube-----

1.) Behind the front speaker grill there is an inspection plate---with it removed you will see a small black plastic block with 6 controls on it; it is the MASTER SCREEN/ FOCUS BLOCK

2.) THREE of the controls left to right are Screen controls(red, green and blue) and the other 3 are FOCUS--IT IS ALL black and you need to look close to identify which is focus and which is screen---you are looking for the BLUE focus control(one of the 6)

3.) With the convergence grid on screen cover the RED and GREEN lens in the set and try to adjust the focus of the blue(I presume you know how to put the set into the Convergence mode?

4.) The only other way to adjust the Blue focus is from the back of the set---with the Red and Green lens covered up place a blanket over the top of the set that covers the whole screen--from the back of the set you will note that all three of the black focal lens have a wing nut---with the convergence grid up and only blue lines present(Green and Red lens covered with a cloth) look from behind the set at the grid---loosen the wing nut on the blue lens and slowly slide the lens left or right until the blue has the best focus possible----if it will not adjust with the focal lens or the front focus control you have a circuit problem.

I do this here for free and if this information helps you take a minute and give me a vote here. If you have any questions or need advice reply to this posting here and I will assist you.

SD TECH

Posted on Sep 15, 2009

Testimonial: "Thank You! Much better quality now! Your advice was dead on. I did not think it was convergence problem....One more Q, where do I send the beer?"

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I have a toshiba tp50h50 rear projection tv and their is a blue shadow behind the words and makes the words a little blurry


Sounds like you need to do a color convergence. If you still have the owner's manual, it will give great detail on how to do this. The convergence menu is accessed from the video menu on the tv.
The tv has three color picture tubes, red, blue and green. The convergence alignment adjust each tube so that color from each tube overlaps each over to create a white image on the screen. Most tv's only allow you to adjust the blue and red colors.
Convergence should be performed each time the tv is moved and at least once annually.

May 16, 2011 | Televison & Video

1 Answer

Magic focus blue is fine, green and red are really blurry, tv picture is almost black and white. all bulbs are on.


Tv have a problems known as a convergence problems,it dead.Any colors lines R,G,B mis alignment,have colors shadows pictures or 3D pictures.The tv convergence board,the 2 STK convergence ICS and some or all it resistors are dead.These parts,must be replaced on the convergence board,to solved the convergence problems.The shop,will cost u $300-350 for parts and labors.

Sep 13, 2010 | Hitachi 53UDX10B 53" Rear Projection...

1 Answer

Lines, a little blurry, a little movement


Projection TV sets need to have all three colors - RED - BLUE - GREEN - lined up correctly on the screen in order for the video to look normal. When its out of alignment the video will look 3D, wavy, distorted, etc. Most of the time you just need to adjust your convergence in the TV menu. If you cannot adjust it in the menu - then your convergence is broken and needs to be repaired.

This is a very common failure on these projection sets and a fairly simple DIY fix. All projection sets including Samsung, RCA, Sony, Philip Magnavox, Panasonic, Pioneer, Akai, GE, JVC, Toshiba, and others at some point will have the same problem.

Common Symptoms include....
  • Screen looks 3D
  • Colors don't line up
  • One or more colors can't be adjusted when using the convergence menu.
  • Screen is bowed or warped.
  • TV shuts off after powering on. Power light will blink. TV may also make a chirping noise.
Here are some photos of convergence problems.

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Here is a quick test....

Using your original remote go-to the settings menu then goto the convergence section.

Try to adjust the red and then the blue convergence.

You should be able to move RED and BLUE in all directions - up, down, left, and right. And you should be able to get the grid straight.

If you can't move them in all directions or cant move them far enough your convergence chips are bad and should be replaced. This is a common problem.

Note: If you TV has as flash focus or magic focus button only try pressing the button. If it fails to fix the convergence your need to fix it. See below for a fix

69189a5.pngCONVERGENCE SOLUTION

You can see some more examples and find a fix using this link on Fixya http://www.fixya.com/support/r2861467-solution_video_looking_whiteish_dull

Jun 10, 2010 | Hitachi 51F59 51" HDTV Projection...

1 Answer

RCA 52" projection tv convergence problems,can i fix it?i try auto convergence? the model is P52920BL and is a 1998 i try the green centering blue & red convergence in the setup of the tv,and it goes back...


My RCA 52 rear projection TV has the letters getting blurry on top and bottom, Picture is OK but visually losing my eyesight staring at blurry numbers and letters.

Is this a bulb or simple fix ??

Mar 28, 2009 | RCA P52920BL 52" Rear Projection...

1 Answer

Sony rear projestion TV has blurry picture.


sounds as if your convergence needs to be set. either through the menu on the tv or remote you need to get to the convergence set screen and you need to line up the crosshairs. this usually happens when the tv is moved or bumped.

Dec 31, 2008 | Televison & Video

1 Answer

There is a picture but it is blurry with a big yellow blur.


Your TV most likely has one or more possible problems.

Problem #1: Convergence Chip Failure ( common problem )

Here are some of the most common symptoms and example photos of a convergence problem
  • Screen looks 3D
  • Colors don't line up
  • One or more colors can't be adjusted when using the convergence menu.
  • Screen is bowed or warped.
701cb04.jpg
77ea520.jpg
f0900cb.jpg
Here is a quick test....

Using your original remote go-to the tv settings then goto the convergence section.

Try to adjust the red and then the blue convergence.



You should be able to move them up, down, left, and right.

If you can't move them in all directions your convergence chips are bad and should be replaced. This is a common problem.

2c07611.pngSolution #1

You need to replace the convergence chips and convergence resistors. Check the site www.TvRepairKits.com. They have put together a kits for most models. If you don't see a kit for your set send them a quick note and they will put one together for you. Their kits include a photo instruction guide, original OEM Sanyo STK chips, convergence resistors, pico fuses, etc.


Problem #2 CRT Fluid is Cloudy

Projection TV tubes have a liquid coolant that is used to keep them from overheating. After many years the coolant in the blue and green tubes will become cloudy and cause the screen to look dull, red/orange, etc. You may even see halos around images.

Picture of a set that needs the fluid changed.

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TV set after fluid change

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2c07611.pngSolution #2


What you will need to do is replace the coolant and clean the crt. You can get a repair kit from www.TvRepairKits.com that includes replacement coolant, photos. instructions, etc.

Dec 30, 2008 | Philips Magnavox 51MP392H Rear Projection...

1 Answer

Blurry, Multi-Color, Multi-Line


covergence problems and its not adjustable you need work done on the convergence board or a new board and realignment which can be timely.

Nov 01, 2008 | Samsung DLP HL-P4663W 46" Rear Projection...

1 Answer

Picture distorted and blurry with color


bad convergence amp ic
http://home.earthlink.net/~oleg.filippov/ConvergenceFix.htm
http://cmpalmer.blogspot.com/2006/11/fixing-my-own-tv-part-ii.html
Sony Convergence
http://www.techlore.com/blog/entry/19694/Sony-Convergence-Repair-My-Sony-TV-has-a-distorted-picture-/
http://www.techlore.com/article/19631/Sony-Convergence-Procedure/

Jan 28, 2008 | Mitsubishi WT-46809 46" Rear Projection...

1 Answer

New PCB SUB - But blurry and color off.


have you tried to also adjust the lenses to fine tune the focus .

Aug 28, 2007 | Samsung HCL4715W 47" Rear Projection...

8 Answers

Blurry tv


Sounds like theres a leaky capacitor in the screen drive circuit. I have seen this problem also be a gassy crt but was able to clean off the grids of the CRT with a crt/rejuvinator. It happens because of low emmissions in the tube and when white is on thats a mix of all the colors, so the tube works harder. I bet when you whatch a movie and the scene changes suddenly to a white or brite scene the pic looks a little washed out. If this is not the case then I aggree with the Pravin and try it on another TV just to be sure .. This is not a repair for a consumer to do, though however it is only a three year old set you stated, so there should be life left in the tube, so im kinda thinking a capacitor is bad. Seek out a yechnician to check this out for you as a TV is not a place to see it you can fix it or to exoeeriment with. Good Luck

Jul 26, 2006 | Toshiba 36A40 36" TV

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