transistor markings question

[NOOBPASTE51]

Hello to all of you in this forum. I have found so many useful things here, that helped a newbie like me to fix some simple electronics..
So,  first of all, let me express my gratitude to this forum and all its members.

I am in NO WAY an electronics expert (not even studied any stuff like this). But many times i have stumbled upon "broken" electronics that need fixing (like replacing some tact-switches in my synthesizer, replacing capacitors, resistors, or constructing a pcb with various components based on other peoples' instructions etc..)
So, now, a new problem arised : my plasma tv has gone black, and based on various stuff i read in the web, it would probably be the YSUS boards' fault.. So i tried to check some electronics components with a multimeter, and found some transistors shorted to ground, and maybe a PP capacitor is leaking ...

Unfortunately, the transistors have some markings i cannot translate to actual specification, and i really need your help in this. There you go:
(transistors with 3 legs THROUGH-HOLE, probably TO-220 or TO-220F packaging, if i say this correctly..):
1)  (1rst line)  0944 /  (2nd line)  F20LC30
2)  1942  /  F20LC30
3)  0544/  F20LC30
4)  0644/  F20LC30

(Transistor SMD with 3 legs (one not to be soldered) and a tab on the opposite side) :
N 4C / 61FC4

I really do NOT have a clue if these are MOSFETs or diodes or regulators. I only found datasheets for the F20LC30 but i cannot identify the numbers before this code, so i am not sure if i should buy any F20LC30 with different numbers..

I would greatly appreciate your help with this.. (please note that my electronics knowledge is quite limited, so be gentle    )

[davekni]

If you've found a part "F20LC30", then the other numbers may just be lot numbers and/or date codes.

[Arcatarter]

I have come across this issue many times while scavenging parts from plasma TVs, many of them have parts which I have been unable to find datasheets for. However I do know that all of the plasma TVs I've seen use IGBTs and rectifiers, and those are typically the components which I am unable to find datasheets for.

The majority of the plasma TV circuit boards I have use IGBTs that are rated for 300 volts and around 80 amps, and the rectifiers are usually around 400 volts and 10 amps. I feel pretty certain that the part number you gave is an IGBT. If pin 1 has a smaller trace than pin 2 and 3, you can be almost certain that it is an IGBT as the gate (pin 1) will almost always have a small trace due to the much lower current required. If you can take pictures of the board, I could tell you almost for sure whether they are IGBTs or rectifiers.

The numbers around the f20lc30 aren't important, as davekni said they are likely lot numbers and date codes.

[Mads Barnkob]

When searching for part numbers from power silicon components, I find it useful to only search for the two numbers and the letters in-between. They are almost always structured as current first, some letter and then voltage rating. 20LC30 would be 20A 300V and LC is manufacturer specific.

As seen here: https://www.alldatasheet.net/view_datasheet.jsp?Searchword=20LC30&sField=3

The prefix of S, DF or SF makes a difference if its a diode or MOSFET, so that is how Shindengen chose to name their devices with a common current/voltage part of the name across different types.