Horizontal Line across TVs

[ToplessZ]

I have two TV that has a blue line across the middle of the screen,(from left to right)
Is this a Horizontal deflection failure?  They both have the same part NTE2331 that seems to be shorted?  One has the two outer legs that are shorted together, and one has the middle and the outer shorted together.  My guess is that none of them should be shorted together correct?

[grantspain]

i would be looking at the vertical frame ic and its circuit,the tv is in the standard horizontal elevation i take it?
if so you would need to check for bad solder joints around the yoke plug,flyback and check the voltage to the frame ic-normally around +25volts dc

the horizontal output transistor if shorted would cause no monitor start up whatsoever and you would probably hear ticking

[ToplessZ]

yea the Tv is in the standard horizontal frame.  What does a frame IC look like? Do you have a generic part number of one so I can look up the data sheet?

[grantspain]

something like tda1675 or an LA type

[ToplessZ]

Foundem, both LA7838 and LA7837.
I noticed on the smaller tv that the LA7837 had some bad solder joints, I soldered them back and turned it on and it popped like a firecracker, then went back to the blue screen.  Not sure what happened there. I might have crossed a solder joint or something, I dont know yet.  I ordered the parts above.

Does anyone here work on TVs alot?  Are the above parts a common failure item for this symptom?

[grantspain]

yeah i only work on monitors for a few years,maybe 10-15

[ToplessZ]

yeah i only work on monitors for a few years,maybe 10-15

good deal then, looks like I got the right man for the job!

[qrz]

loose connections is a common fault on vertical output IC's. ( regardless of brand )
heat generated over time tends to degrade the solder.
 heat will also cause 'lytic caps to degrade .  and that is why so many mfgr's place them
so close to big heatsinks   

on the ic that popped , check the diode /resistor on the 24v line .
the res is likely open , and the diode may be shorted......     

make/model of tv  ?

qrz   

[ToplessZ]

Fixed the one that "POPPED".
The other no luck.
Only thing I have done is replace the vertical output IC.
It has a thin bar across the screen that changes from green to blue. It a 36" (maybe 39 not sure) Panasonic.  The only part number I could find on the chassis was TNP190157.
I would do a cap kit, but there are like a 100 of them!  Ayn guesses?

[grantspain]

yeah,google the frame ic and locate the voltage input pin then check the voltage at that pin.
most likely the frame ic popped and fried a protection resistor from the power supply output

[ToplessZ]

so the frame IC will affect video?  The TV powers on correctly and has sound, it just doesnt show anything other than the bar across the center.
Im not sure what a frame IC looks like.  You got another generic part number so I can look it up?
Thanks for the help!

[qrz]

a model # would be helpful.( there is a chance that i have the service manual)

meanwhile, a common panasonic vert out ic was an AN5521

spec sheet here :

http://www.alldatasheet.co.kr/view.jsp?Searchword=AN5521

the pic will give u an idea of what to look for . (and it WILL be on a heatsink)

also see la7835, la7833, tda1675, tda1771.......

qrz

[ToplessZ]

I already replaced the vert output IC, which I think you called it a frame IC? 

[grantspain]

yes thats correct i do sometimes refer to the vertical output ic as the frame ic,i think its an british thing.

now you should be checking the feed voltage to the vert ic,if you google the ic number and download the datasheet it should give the ic pinout and state the working voltage and to which pin it goes,from that you can meter and trace the voltage

also worth checking the resistance of the vertcal yoke

[ToplessZ]

okay that makes more sense.  13 tiny legs on this thing, Im gonna have to solder a wire to run a few feet so I can keep clear of the things with the TV on!( No room for hands and meter probes in this thing!)
So if Im not getting the proper voltage or any at all, then theres probably a resisitor or cap that has failed that is connected to the feed voltage line somewhere?

[Arm123]

Just my 2cents worth, but i notice when ever there is a vertical collaps and the frame IC / Vertical IC is at fault...  There is usually a dead diode or resistor that needs to be replaced as well.  You should probably check for these.

[ToplessZ]

Thanks for all the help, this thread is finished and all is working.  Found a diode that wasnt letting any power though, replaced it and its working like new.