loopyloo (26-07-17)
That'll certainly save a lot of time for targeted hands-on probing
Check for 400V (approx) on Q101, if there's none then LB106 is likely to be open circuit - the fault current that destroyed the fuse and FETs went through there.
Last edited by Skepticist; 20-07-17 at 12:06 AM.
loopyloo (26-07-17)
To satisfy my curiousity, what is the model number of the television receiver.
The thread title suggests it's an LG, but which model?
(I couldn't see it mentioned elsewhere in the thread)
loopyloo (26-07-17)
I found a diagram for it but it's near impossible to read :
loopyloo (25-07-17)
tristen (20-07-17)
400V was a major over-estimation (it was late when I posted that), should be around 340V across the large cap (120uF 450V).
An average of about 170V across each inverter FET would indicate they are actually running (switching alternately at high speed) and yet there's no 12V or 24V output?
Got me thinking about C114 (18nF 800V) if the FETs are switching but so many possibilities need a lot more data to narrow it all down.
Last edited by Skepticist; 20-07-17 at 02:06 PM.
loopyloo (25-07-17)
You will find the complete service manual for that at .
The manual appears to contain relevant circuit diagrams.
The parent url is .
Some members might remember that I have mentioned the jordansmanuals website in past threads.
Loopy, I suggest that you write it on the back of your workshop door for future reference.
loopyloo (20-07-17)
It's part of the power factor correction system. If you're reading a full 340V across C610 it's not interfering with the supply enough to cause a problem.
The standby 3.5V supply runs off the same bus and it's fine, it also supplies the Vcc to the PFC and the inverter controllers.
loopyloo (26-07-17)
loopyloo (26-07-17)
loopyloo (26-07-17)
The 'UX...' ?
Looks like a spark gap or a neon to me (just going on lack of polarity markings)
loopyloo (26-07-17)
CAn I phone a friend. has a Samsung tone about it with those designators. Spark Gap, Surge protection
Last edited by tw2005; 21-07-17 at 07:46 AM.
loopyloo (26-07-17)
Ha ha yep Samsung. You done well.
Spark gap is what I figured too. Should be SG803S lol.
Now back to the LG.
I've got 340v across that C610. Also got 340v on the drain of Q601, Q602, Q101 but nothing on Q102. What do you reckon ? IC101 gone ?
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