Projection screen turns red after 3 seconds

[kilgorekb]

I have a Hitachi Ultravision 57S715. When I turn it on, it looks great for about 3 seconds, then everything goes red. I would like to repair it myself if it's cost effective to do so. I don't know jack about TVs, but I can read. Any suggestions on where I should start?? or if I should just punt??

[ben7]

Re: Projection screen turns red after 3 seconds

Sounds like either a typical bad solder joint, or problem with the convergence IC. Could we get some pics of the insides?

[f67bird]

Re: Projection screen turns red after 3 seconds

If you can post some pictures, please also include one of the picture when it acts up, and a few of the crts from the front of the set. You should be able to remove the speaker grill and the cover...(both located in the front of the tv) to the crts.
If everything is going red - I have a feeling that the problem is the red crt arching internally.
If you can unplug the tv, then separate the red crt board from the red crt (sometimes there is silicone glue between the crt and board) and make sure to not let the board touch any metal while it is hanging, and turn on the set with the red crt board disconnected... you will have a strange colored picture, but it will not change after 3 seconds like before if the red crt is causing this.
Oh, the easiest way to determine which of the 3 crts is the red one is to turn on the tv with the speaker grill and crt cover removed, and look up at the crts...one will have green light, one will have blue light, and the other will have red light- that's the red crt.
Be EXTRA careful not to bend any of the metal crt pins while moving the board to the side or reconnecting the crt board.
The is a small possibility that components on the red crt board are causing it instead of the crt itself.
Let us know what you find out.

[kilgorekb]

Re: Projection screen turns red after 3 seconds

f67bird,
I'll try your steps in a minute. In the meantime, here are the pics I took.

[kilgorekb]

Re: Projection screen turns red after 3 seconds

I've got some new symptoms to report. So I'll just list all again to recap and update.

-I turn on the TV.
-The TV looks fine.
-After a few seconds, the picture goes red.
-After a few more seconds, I hear a click and there is no picture. The blue LED power indicator on the front is not lit.
-I press the On button and nothing happens.
-I press the Off button and I hear a click.
-I then press the On button and I hear a click, but the picture doesn't come on.
-I unplug the TV.
-I plug in the TV.
-I press the On button.
-The TV turns on. The blue LED power indicator on the front is lit.
-The TV looks fine for only a split second.
-The TV then goes red.
-After a few more seconds, I hear a click and there is no picture. The blue LED power indicator on the front is not lit.
-Wash and repeat.

Here are a couple of pictures when red:

[kilgorekb]

Re: Projection screen turns red after 3 seconds

I disconnected the red CRT board. Problem solved.

So do I need to replace the board, or can I try some troubleshooting on it?
If I had to replace it, do I need to replace it with the exact Hitachi part# ?

[kilgorekb]

Re: Projection screen turns red after 3 seconds

Here's a pic of the red CRT board. Part # JK08674-C

[f67bird]

Re: Projection screen turns red after 3 seconds

More than likely it's the red tube itself that is causing this.
The photo of the crt board is out of focus, can you get one or two clear ones of both sides (top and bottom) of the board?
One way to tell if the crt is causing this can be to carefully reconnect the crt board without bending any of the metal pins sticking down from the crt...
and turn the tv on while GENTLY rapping something light (like a plastic ball point pen, or a plastic or wood screwdriver handle) on the side of the red crt neck. The neck is the roughly 1" diameter glass tube section that is between the deflection yoke and the neckboard.
Rap on it, but not hard enough to break glass.
Most of the time you will see the red flash and maybe straighten out for awhile if the crt itself is the problem.

[kilgorekb]

Re: Projection screen turns red after 3 seconds

Ok, well this is the point where I should stop and ask.. how much would it cost to replace the CRT?

[f67bird]

Re: Projection screen turns red after 3 seconds

Sometimes this problem can also be caused by the crt board or possibly even the video circuit that leads into the crt board.
In some cases its possible to verify that it's the crt board or video circuit that is causing this issue by disconnecting the green crt board from the green crt (the green crt is always the one in the middle), and letting it hang
down... and moving the red crt board over and connecting it to the green crt. Sometimes the wires that connect to the red crt board are long enough to let you move it over to the green crt. Also many times either the red or blue crt will be mounted 180 degrees apart from the other two crts. You can look at the crt socket where the pins come out of the crt on the green and red crts to see if they are oriented in the same direction.
If you are able to connect the red crt board to the green crt and turn the tv on... you will know if the red crt board and video circuit that drives it are good or not.
If good, the green and blue crts will come up with pictures on them and the set will not shut down. If this happens- the red crt itself is at fault.
If the red crt board or video circuit that drives it are bad, the green crt will now light up very brightly and the set will shut down like before. If this happens, the red crt may be good.

[f67bird]

Re: Projection screen turns red after 3 seconds

The red crt itself lists for about $275.00, then there is the matter of changing it out and setting the focus and convergence up. You would just about have to find a set for parts to get a tube at a reasonable price.

Can you get a few photos of the paper tag that is located near the red crt deflection yoke? Your photo above sunp0019 looks to show the tag on the blue crt. Usually the tag for the green crt has a green colored outline to the tag, and the red crt has a red outline...
Many times lots of different big screen tvs use the same number crts. The tube may be easy to find by the number on the tag.
Changing it out will be harder, but doable.

UPDATE: this website shows a used red crt for your model with yoke and lens included for less than $65.00 http://www.bigscreenparts.com/servle...--/Detail.html
If you determine that the red crt is definitely bad, you may want to call them to verify that the crt, and yoke, along with the lens are all included as shown in the photo... that will save you lots of trouble.
The main complication about changing out the entire assembly is removing the high voltage lead from the flyback. I can guide you through that though.

[kc8adu]

Re: Projection screen turns red after 3 seconds

if it does have an h-k short you can use an isolation transformer.
that is of course as long as the crt isnt now beat to death running at uncontrolled full beam current.
i would think it would shut down fast enough to prevent damage.
measure from k to chassis ground.should be comparable to the blue and green.
if ok till you let the red warm up then low its the crt.

[kc8adu]

Re: Projection screen turns red after 3 seconds

btw that site may be a ghost.
putting anything in your cart gives a 404.

[kilgorekb]

Re: Projection screen turns red after 3 seconds

The tag is P16MAB00RFA. The tags on the blue and green are each different than this one.

Here's a better pic of the board. The bottom has a shield soldered to it.

[kilgorekb]

Re: Projection screen turns red after 3 seconds

Well, I'm making an executive decision. I'm punting. Thanks to all for the help. If you want a free TV, it's yours. Just have to pickup in Northwest AL