Question about Akai PT4298HD Rear Projection Television

1 Answer

Blue washes out whole picture

Hi, I just bought an Akai PT4298HD for cheap because it needs fixing. I am very familiar with CRT projectors. I used to buy them, fix them up and resell them. I still run an old Electrohome CRT projector in my theater room. Anyway, on this Akai tv the blue is overdriven. It washes out the whole picture. When I adjust the drive in on the board at the bottom of the yoke, it doesn't make a noticeable difference. I tried focusing the tube, but it's so washed out, focusing the lens makes no difference. What I'm really looking for are the technical specs on this set, or for someone who's had the same problem to point me in the right direction. Thanks for any help!

Posted by on

  • Anthony Case Oct 21, 2007

    Hey thanks retrohack. By the time you had posted I had figured it out. The blue tube was leaking and had nasty stuff inside it. The bacterial growth you described. It was leaking a little bit already, so I drained and cleaned it and put in new heat transfer fluid. It looks great after that. I must say, what a crappy seal design. After refilling it and cleaning the seat area for the gasket, I still didn't feel too good about it, but I made a little drip pan underneath it just in case. Thanks for the help.

  • Anthony Case Oct 21, 2007

    Hey thanks for the help Retrohack. It was the algae growing in the tube. I noticed when I got it apart that the tube had been leaking a little bit, and saw the nasty stuff right away. I drained and cleaned it and refilled it with new heat transfer fluid. You were also right about the design of the seal. It wasn't leaking when I put it back together, but I still don't like it. Anyway it looks great now. Thanks for the help!

×

Ad

1 Answer

  • Level 1:

    An expert who has achieved level 1.

    MVP:

    An expert that got 5 achievements.

    Governor:

    An expert whose answer got voted for 20 times.

    Scholar:

    An expert who has written 20 answers of more than 400 characters.

  • Contributor
  • 27 Answers

Hello....I have been working on these (and it's Samsung counterpart - HCM4215) for about as long as they have been on the market. I have ran into this problem on the blue and green CRT many times. Most of the time it is a bacterial growth in the glycol coolant. This model is notorious for leaky tubes (they have the worst rubber seals ever invented for a CRT), and air bubbles trapped within the tubes which allows for an algee-like growth in the fluid compartment between the screen and the primary lens. If this is the case, you will have to remove and drain the CRT, completely clean the assembly with denatured alcohol, and refill it with glycol coolant. If you have rebuilt these things before, this is probably no new task for you!!

 

I have also ran into bad components on the CRT driver boards with this model. They have always been the variable resistor for the drive (VR501 1Mohm) or one of the three 1/2W resistors right next to it associated with screen circuit. If you don't see retrace lines, then I would bet on the algee!!! Hope this helps out.....please let me know how you make out on it.

 

jdavid_3343@yahoo.com

 

 

 

Posted on Oct 21, 2007

  • Jerry Coleman
    Jerry Coleman Oct 21, 2007

    By the way...on one occasion, I did run into a bad focus pack. You could always try to switch the green and blue focus wire....like I said, it only happened once...but it's and easy check. Good luck!

×

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Good luck!

Posted on Jan 02, 2017

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

2 Answers

AKAI rear projection TV won't turn on


possiblity convergence needed...
main power board malfunctioning
contact akai service center

Apr 26, 2010 | Akai PT4298HD Rear Projection Television

1 Answer

Vertical line on rear projection TV - Akai PT4298HD


this is an indication of a burnt crt. unfortunatly to fix this the crt will need to be replaced. such a repair is something i would recomend to a non tech. theres adjustment issues

Oct 30, 2008 | Akai PT4298HD Rear Projection Television

1 Answer

Akai PT4298hd


You may need the change the coolant in the blue tube. Convergence is when the picture will look 3D Let me know if you need more information.

Apr 25, 2008 | Akai PT4298HD Rear Projection Television

1 Answer

Akai pt4298hd picture is to bright


Sounds like dirty lenses to me. Do some research on optics cleaning for RPTVs. AVS is a good place to start. Also try this:

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

Mar 16, 2008 | Akai PT4298HD Rear Projection Television

2 Answers

Akai PT4298HD..Please help!!


Normally, yes.
Make sure you get the CG Board Part number:
BP94-00155A
There are other boards in this set that say convergence, but, they are not the boards you want.
Available at:
Andrewselectronics.com
Easy to replace.
Any questions, reply to this post and I will respond.

Jan 13, 2008 | Akai PT4298HD Rear Projection Television

1 Answer

Picture quality


possible blue crt is defective. also the tube needs filament,blue drive and screen voltages/high voltage to lite up. these should be ck'd only by experienced tech or OUCH! john

Aug 20, 2007 | Akai PT4298HD Rear Projection Television

1 Answer

Akai


yep you need convergence amp replacment for your set..very common prob call experienced repair person for this job use original replacements....john

Jul 31, 2007 | Akai PT4298HD Rear Projection Television

1 Answer

Akai tv


have a good tv guy repace you convergence amp's john

Jul 31, 2007 | Akai PT4298HD Rear Projection Television

1 Answer

Hourglass shaped red


I need to see a picture of the TV set. send a photo to techman32k@yahoo.com

Jun 05, 2007 | Akai PT4298HD Rear Projection Television

1 Answer

AKAI PT4298HD


If you have a good picture except for a missing color all the various circuits are working OK. Most likely you have a bad solder joint or component in the red circuit. This would also be indicated by the fact that ocassionaly the red pops in. If you have the experience remove the boards and inspect for cracked or cold solder joints. Resolder anything that looks suspicious. If this does not fix it you will have to troubleshoot the red drive circuits from the CRT back to the video IC. Another possibility is that you have a bad/intermitant red crt. I doubt that you have the equipment to check this but you can test it by moving the green crt board to the red crt. If it now works the red crt is OK. If all this fails you will need to find a reputable repair shop to look at it. If the unit is more than 5 years old it may not be worth fixing. Good luck.

Jun 02, 2007 | Akai PT4298HD Rear Projection Television

Not finding what you are looking for?
Akai PT4298HD Rear Projection Television Logo

57 people viewed this question

Ask a Question

Usually answered in minutes!

Top Akai Televison & Video Experts

Jaime Hernandez

Level 3 Expert

2336 Answers

The Knight
The Knight

Level 3 Expert

75276 Answers

yadayada
yadayada

Level 3 Expert

78919 Answers

Are you an Akai Televison and Video Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...