Samsung TV (model number coming soon) dead Darfon v183 inverter board, what to check?
Good evening folks. I was going to write this from work where I've got this TV at the moment, but I got carried away with work and I'm writing from home instead, so that's why I said "model coming soon" - I don't have it on hand right now to check. Anyway, this Samsung set has a dead inverter board. Everything else seems to work normally, as it passes the "flashlight test" and responds to commands just fine. From the pictures I took, I can read "Darfon v183" in a corner of the board and upon searching for this, I did find it indeed, though I'm not sure if this is the actual model that people might be asking for, so sorry if that's the case. Taking some basic readings, immediately revealed that a couple of the 3A SMD fuses are open (there's 6 of them in total - you can see two in the close-up photo) which told me there's a short somewhere and sure enough, probing the MOSFETs which correspond to those fuses gives me dead-shorts across all of the pins. These ICs are p2804nd5g twin N and P channel FETs in one package, so it's just a matter of replacing them, putting new fuses in and hoping for the best......is what I thought at first, but then that got me thinking about the actual cause of failure of these FETs. In other words, if I just replace the bad FETs and power up the set, they might just go out again after a few minutes because they weren't the initial problem, which brings me to my actual question: what should I look out for when I got bad transistors on an inverter in general ? Could the transformers driven by the FETs have issues ? Any way of checking ? (There's 10 of them btw, to spare you the counting 
). I doubt the lamps can lead to dead FETs like this. I've used the trick of measuring the resistance in the primary and secondary windings with my meter before for small monitors which only have 1-2 transformers (pretty reliable method), and I gave it a shot here as well, but this one seems to be inconsistent, as my readings range from around 5.9 kOhms to 1 kOhms and between, though that could also be because the shorted components which I haven't removed. Any clever tips to avoid wasting money and slaving away only to end up with another set of dead FETs ?
). I doubt the lamps can lead to dead FETs like this. I've used the trick of measuring the resistance in the primary and secondary windings with my meter before for small monitors which only have 1-2 transformers (pretty reliable method), and I gave it a shot here as well, but this one seems to be inconsistent, as my readings range from around 5.9 kOhms to 1 kOhms and between, though that could also be because the shorted components which I haven't removed. Any clever tips to avoid wasting money and slaving away only to end up with another set of dead FETs ?
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