27


  #1  
Old 07-28-01, 10:54 AM
Guest
Visiting Guest
Posts: n/a
FOR MONTHS NOW, WHEN I TURN ON MY NEC TV27"stereo , STATE OF THE ART IN 1991(has built in stereo amplifier with multiple outlets for speakers).....when i turn on the tv, the sound is usually on,howver withih 10 minutes i will hear small electrical "snaps" and the sound will go blank. picture ok.

a little humor,one time i got some frustrated,i banged the side of the TV and the sound came back on!

of course,its 100's of dollars to probably to repair and a new tv would probably be better with that price.


thanks,sharky
 
  #2  
Old 07-28-01, 12:08 PM
Smokey
Visiting Guest
Posts: n/a
Thumbs up

Good Afternoon, Sharky:
Welcome to DoItYourself.com. If you will read any number of posts on this forum you will see similar situations with television sets. While the symptoms are different, the cause is the same. Bad solder connections! The Japanese electronics industry seems to be plagued with them.

Circuit boards are all manufactured by machines these days. Machines install the components on a predrilled board, it goes through a solder bath, and the result is a circuit board that ends up in your television set. But, it is inevitable that in all this mass production that one solder connection didn't turn out as well as they would have hoped.

So, you are going to have to take the back off the set and do a little poking and prodding with a non-metallic wand of wood or plastic. You will have to poke around the circuit board that is your sound driver, and you will have to find the "sensitive" spot that causes your sound to come and go.
Then you will have to take a low heat pencil soldering iron and a little 60-40 electronic solder (the small stuff) and resolder the connections on that board in and around the "sensitive" spot. You may have to do this two or three times until you "get lucky" and hit the right one.

But, that is the sum, total, and existence of your problem.
You can do it yourself or have a shop do it for you. But, the outlook is the same.

Smokey






 
  #3  
Old 07-28-01, 03:10 PM
Guest
Visiting Guest
Posts: n/a
thanks smokey

that's a mil smokey!
 
  #4  
Old 07-28-01, 05:59 PM
bigmike
Visiting Guest
Posts: n/a
Cool ZZZZZZZZZZZZZ

Buzzzzzzzzzzzzzzzzz, snap, pop... Watch out for HIGH voltage Around the big "Flyback" (does it have one Smokey?) or the Anode that goes from the board to the CRT (picture tube). Make you dance the funky chicken and not in a fun way
 
  #5  
Old 07-28-01, 08:31 PM
Guest
Visiting Guest
Posts: n/a
thanks smokey/big mike.

i'll open up the back,see one of those"high
voltages warning" and probably chicken out.
maybe not. but i know electicity is pretty
powerful.

if i do get it repair,any ideas what it might
cost. i notice most places charge 50-75.00
just to look/estimate.


it might take weeks to follow up at this
thread,but i will

thanks again

it's funny how the traditional banging on
the side of the TV worked.
 
  #6  
Old 07-29-01, 07:15 AM
bigmike
Visiting Guest
Posts: n/a
Cool Solder joints

Like Smokey says, it's just solder joints and I wouldn't think it would cost alot to repair.
 
  #7  
Old 07-30-01, 08:11 AM
lucman2
Visiting Guest
Posts: n/a
Thumbs up

hello sharky,
Yes, it is solder connections and this is very common for NEC televisions....Remove the back cover and look for the biggest chip with about 64 pins on it. It is located close to the front left corner of the TV. You will have to slide out the "main circuit board" towards the rear of the set to get at it. Lift the main board so you can get at the bottom side of that big chip.

You will just have to solder the last 4-pins on each end of the chip and on each side of the chip. This always cures the problem without any parts needed

If you need the chip number or anything else...just let us know.
Good Luck Sharky.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description: