NEC TV Help

[TJB]

I have a NEC FS5197 TV, which I tried to repair recently without a cct and
failed. I have since tracked down a circuit and had another go, but argh
I'm still having trouble!

The set has sound, no picture but the OSD works okay. Something is
preventing the picture from appearing. Video from the tuner or AV input
appears at the jungle IC: TB1226EN but doesnt make it out. My initial
thoughts where faulty x-ray/protection cctry, but that seems to be okay.
This leaves either a faulty jungle ic: TB1226 or faulty micro: M37212M8.
Anyone got any ideas?? Unfortunately the set is old and not worth spending
alot of money on it.



Thanks in advance
TJB

 

[[email protected]]

I have a NEC FS5197 TV, which I tried to repair recently without a cct and
failed. I have since tracked down a circuit and had another go, but argh
I'm still having trouble!

The set has sound, no picture but the OSD works okay. Something is
preventing the picture from appearing. Video from the tuner or AV input
appears at the jungle IC: TB1226EN but doesnt make it out. My initial
thoughts where faulty x-ray/protection cctry, but that seems to be okay.
This leaves either a faulty jungle ic: TB1226 or faulty micro: M37212M8.
Anyone got any ideas?? Unfortunately the set is old and not worth spending
alot of money on it.



Thanks in advance
TJB

If all the voltages on the jungle IC are correct, and video goes in and
nothing comes out, it sure sounds like the jungle IC has gone to the
great heavens above. How about the sync outputs, anything there?

H R.(Bob) Hofmann

 

[TJB]

If all the voltages on the jungle IC are correct, and video goes in
and nothing comes out, it sure sounds like the jungle IC has gone to
the great heavens above. How about the sync outputs, anything there?

H R.(Bob) Hofmann

Voltages are okay, sync okay. I can force a picture by removing the OSD
Y out from the micro to the jungle IC. So either the jungle IC is not
responding correctly or the micro is not controlling it correctly or
something is locking out the video signal on the micro.

TJB