JVC LT-42EM73 Flashing solid colors and turns on as soon as plugged in

[Doc38343]

JVC LT-42EM73 Flashing solid colors and turns on as soon as plugged in.

- TV turns on and is stuck in color test pattern mode forever.
I tried many resets and things from internet searches and nothing worked.
I even bought a remote. (this TV is a rescue from guy about to throw in dumpster) none of the suggestions to get it out of maintenance mode worked.
SYMPTOMS:
No red standby light at all. Soon at plugged in the led went blue. Screen said "Please Wait...." then it started alternating between colors solid filling entire screen. Holding Power any amount of time = nothing. Holding power Vol + and menu... = nothing. Another forum said main board E-prom was failed.
I ordered the E-prom chip from Shopjimmy/Ebay (free shipping thru ebay)
Cost was $15...
Important Note to any attempting to do this.
Very hard to do this chip change. There is a VERY TINY capacitor right beside leg 4 of the e-prom and unless you have a soldering microscope and micro iron you may have trouble. You will need your smallest tip and work very carefully. (That capacitor is the size of a flake of pepper) I mentioned this because i knocked mine off when removing the old chip and had one heck of a time putting it back. If you are rock steady handed you will have no problem. Also it actually may function without that cap but i didn't want to chance it. There is also a big metal heat sink soldered on the board over the processor and e-prom you will have to remove. This is also hard if you don't change tips or irons. Use the biggest tip you have and highest setting on iron because the heat sink will displace a lot of the heat. Same for putting it back.

Here is the good news I did it successfully and am now watching the piece of garbage that is now my treasure. Total cost to me a remote $17 an E-prom chip $15, about a total of 3 hours of my time, including time wasted trying to push buttons to get it out of maintenance mode and research.

It has a decent picture so i am happy. Sorry guys I did not think to take photos of the steps but i will include some of the board and the top of the heat sink. Next time i will try to photo document better to help others.

[Doc38343]

Re: JVC LT-42EM73 Flashing solid colors and turns on as soon as plugged in

Added Photos.
The E-PROM chip was U17 and it is under the heat sink about where the big sticker with the UPC code is.
If I had not have had that cheap USB microscope I would have lost and never got that Tiny capacitor back on the board without a direct short to ground.
You may have good optics and irons about 40x would work barely.

I would not recommend trying this at beginner levels.
I literally could not see that cap with my naked eye. It looked like a solder speck to me.

Git er done.

[dskall]

Re: JVC LT-42EM73 Flashing solid colors and turns on as soon as plugged in

Soldering is no longer the easy part of electronics repair

[Doc38343]

Re: JVC LT-42EM73 Flashing solid colors and turns on as soon as plugged in

"There is a VERY TINY capacitor right beside leg 4 of the e-prom"
Actually meant to say leg 5

Very nice picture!
Now i know why the main boards are $90

[diif]

Re: JVC LT-42EM73 Flashing solid colors and turns on as soon as plugged in

Soldering is no longer the easy part of electronics repair

It's because we have easier access to instant solutions but soldering is an individual skill, there is no short cut to the solution. It's down to practice and skill and having the right/decent tools helps.
It depends what you are diagnosing. I can remove and replace faulty components on laptops usually far quicker than I find them.

[dskall]

Re: JVC LT-42EM73 Flashing solid colors and turns on as soon as plugged in

I am referencing from leaded solder and large components. Soldering then was an easy skill to acquire. Seldom did you destroy a board by soldering or desoldering.

[ken539]

Re: JVC LT-42EM73 Flashing solid colors and turns on as soon as plugged in

:[QUOTE=Doc38343;756589]JVC LT-42EM73 Flashing solid colors and turns on as soon as plugged in.

I want to thank you for the info on the TV above. I had the same problem. it. - TV turns on and is stuck in color test pattern mode forever.
I did not want to buy a schematic and no one showed where the E-prom was located on the board so glad you included this info.
Bought the U17 chip from shopjimmy on E-bay and finally got it in place. Had a heck with the heat sink and finally used my old 125/150 watt welder pistol iron. I use to do a lot of old school electronics like back in the tube days. You are right about the very small capacitor. I thought I had knocked it off but just covered it up with the burnt resin. I only had a small pencil type 40 watt iron but took an old tip and ground down to a very long lead size tip and it worked well. Only had a table light with a magnifier lens built in but got the job done. For anyone else, when finished soldering, the last two pins next the small capacitor (5 & 6 I believe) and close end of the small capacitor all showed to be connected, but I could not see any cross solder joint, so left alone. P.S.- only used the diode setting for checking connections with meter, so as not to burn out any small parts, which a continuity check might do.
TV works fine now.
My thanks for all the great info. Ken