LG22LH2000 TV, Lien Chang AIP-0190 schematics anyone?

[OniJon]

I found this TV from my workplaces electronics waste. I know it's old 2009 model and only hd ready, I just took it out of curiosity and for something little to work on. It has that Lien Chang psu mentioned. On a first look it has one resistor that's exploded, sus'cons that will need replacing juat because they're crap and according to youtube, maybe a power driver ic is in need of a replacement. Pictures are also now up.
IC I'm talking about is strw6252 and blown resistor (or a fuse?) is R111 (dead center in the picture between main filter caps and yellow trafo), which of I have no idea what it should be because can't find schematics.

[R_J]

Re: LG22LH2000 TV, Lien Chang AIP-0190 schematics anyone?

R111 is a 2amp/125, 20N series pico fuse, also check R108 (in heatshrink), pin5 to ground, it should measure 0.4Ω It is likely good. I would replace the ic and fuse and see if it works, if it does, I would replace C105, then I would replace the other caps if you like, but they don't look bad yet.

[OniJon]

Re: LG22LH2000 TV, Lien Chang AIP-0190 schematics anyone?

Thanks! I ordered glass tube pico fuses at 2A 250V, they should be okay or is the inrush current capability in those 20N series very important? Pin 5 to ground, R108 measured around 0.4 like you said. I also ordered new IC and better caps. Gonna report what happens when I replace all of those.

I don't think it hurts anything to add more filtering like let's say, adding another 25v 1000uf cap to missing point at C202? What about C204, what value would be good and why it's not there? Because I have loads of caps, better to use them than let them dry.

[R_J]

Re: LG22LH2000 TV, Lien Chang AIP-0190 schematics anyone?

These power supplies are used in many different models, there is no need to add more capacitors.

[OniJon]

Re: LG22LH2000 TV, Lien Chang AIP-0190 schematics anyone?

These power supplies are used in many different models, there is no need to add more capacitors.

I know they are used in many models but I was just curious would it help with longetivity to add more filtering or would extra capacitance hurt something? I'm more than capable at component level changes, fixes and measuring stuff but designing these things is not my strong point. So "what does this do in this circuit" is out of my league a bit.

[R_J]

Re: LG22LH2000 TV, Lien Chang AIP-0190 schematics anyone?

Adding an extra 1000µf won't hurt it, the extra added capacity will add a bit more current (not very much) as it charges up the extra capcitor.
If there was too much extra capacity it could damage the supply diode, or more likely put too much strain on the primary circuit as it would look like a short as the capacitors charged.