Datasheet

http://www.instructables.com/id/Dell-W5001C-50quot-plasma-fix/
step 5: Replacing the controller chip
The first thing you need to do is get rid of the defective part, U501.
One method is to remove the chip by getting rid of the solder holding it in place. Either use a solder sucker desoldering station (if you have access to one) or solder wick
to remove the solder then pull the whole chip out. Careful with the solder wick. If you heat up a pad too much, you WILL lift a trace, effectively destroying the board. It's
very hard so get it right with the solder wick.
I used the desoldering station to clear the lead holes. Then, I attached the SIP sockets to the new part, placed it into position, tacked the part by soldering pins 1 and 8 to
hold it into place, and then soldered the rest of the pins. The reason for using the SIP sockets and not a normal 8 pin socket is because the width of the holes is unusual.
DIP parts are normally 300mils wide however the width used on this board for the DIP parts is about 340mils (when I say width I mean from say the center of the hole of
pin 1 to the center of the hole of pin 8.) A normal 8 pin DIP socket will not fit, hence using two strips of SIPs. However, mhra08a has used Radio Shack 8-Pin IC Retention
Contact ($0.48 Model: 276-1995 Catalog #: 276-1995) with success.
Better Method(if you don't have a desoldering station)
I suggest just cutting the leads off the old part and soldering in a strip of 0.100" pitch SIP sockets to the old leads that are left sticking up out of the board, ie a strip of 4 on
one side and another strip of 4 on the other. Try digikey ED7064 . This way, there is no desoldering and you'll have a socket there to make it easier if you have to replace
the part again. You must be very careful when using a small side cutter to snip the leads from the chip (this is the simplest way to do it however). The action of the cutter
will push the lead and the chip to the side, putting lots of stress on the hole that the lead is soldered into. Again, damage of the circuit board could result.
Also note jackohound's method he describes in the comments section:
"As I didn't have a desoldering station, or a small enough side cutter snip the U501 leads, to I used a Dremel tool with a very small cutting disk to carefully cut teach of the
leads from the old chip. This required a steady hand, but it avoided putting any stress on the board. I removed the old chip body and used a handheld spring-loaded
desolderer to remove solder from each of the holes."
After the chip body is removed, you can solder the SIP sockets to them. Watch out because when you touch the soldering iron to the lead you will also melt the solder in
the lead hole and the lead may move, fall through, or cock to one side. You might try first soldering a solid wire to all four leads on one side to keep them in position as
you solder the SIP sockets.
Make sure you install the new part with the right orientation! Otherwise you'll probably blow a fuse on the board(best case) and may take out some other parts as well.
Image Notes
1. Current mode PWM controller area for Va circuit, high voltage un-isolated side.
2. Va transformer provides isolation.
3. Isolated side of Va circuit.
4. Va power MOSFET and current sense resistor.
5. 120V input.