Hello
everyone!, Im new to the site but have been lookin around for a
bit and like what I see , u guys know your stuff!. Anyways I was
wondering if you guys could help me out on this, I've recently
got a Sony KP-46S55 in my possession for free, It has a bowtie
picture and the colours are wayy off.. I think the guy I got it off may
have tried fixing it by adjusting potentiometers in the front...
yay.. I've read about convergence IC's going out and
blowing pico resitors. Im taking this kinda stuff in school and
feel confident enough to fix this. I've estimated the STK's, heat sink
compound, and resistors to be about 40 bucks. give or take. but
these are the largest IC's I've done! and I wanted to confirm that the
IC's I've pointed out in The picture (STK-4278L) are the convergence
IC's to be replaced on my model. This would be swell if I
could get this 50" going, while Im here at school 
If
anyone could give me a little bit of a advice about these
IC"s, and some more inforamtion about heatsink compound/
walkthorugh, That would be very much appreciated!! Thank you..
I can't really tell from your photos but I have done the same repair on my Sony. On mine the STKs are on large silver, metal, finned heatsinks. You need a de-soldering tool and a very fine tipped soldering iron. Remove the old STKs by de-soldering one pin at a time and not doing adjacent pins consecutively (to avoid overheating the circuit board). After that remove the old ones and spread a layer of heatsink compound on the new ones then screw them to the heatsinks. Next carefully solder the pins on the new ones. You want the new solders to completely cover the eyelet holes but not flow beyond them.
Find your pico fuse locations from a service manual http://www.techlore.com/group/2/Technician-s-Corner/ and check them for continuity. On my Sony all the fuses on the D board were fine.
The next step is to check the voltage levels to the STKs. You should have the same 22-25 volt positive and negative on the appropriate pins (see the manual for the voltages on your model). On mine the negative voltage was off due to a blown pico on the G board (power supply). I replaced that and now I have a 2004 57" HD ready widescreen TV for $38 and 3 hours of my time.
I thank Larry Dillon on this site for his excellent advice that I have used to fix 4 TVs simply by reading his posts. I've never posted before myself. He really knows this stuff!
Im just having trouble pinpointing any other components that I should replace, because if the STK's went how high of a chance is it that somthing else is pooped.. So if I swap out these STK's can I turn on the set and go into service mode without worrying about blowing the new STK's?
I advise you to check all the pico fuses. When the STKs go out they often take the fuses with them. That's why I suggested you check the voltages going into the STKs. Picos look like resistors but they will be labeled with an f on the board and only have a single colored stripe on them. As for service mode, you may not even need to go there. I didn't need to and the set is working great.
SoooooooOOooooooo I finallllyy got the parts, after waiting on the shipping. I installed the STKS no prob.. but I still have convergence issues. I have removed G board because I wanna replace the fuses, and i was curious..
but Im having trouble, the fuses I have dont look execatly like the older ones, neways I was wondering if anyone cold explain which fuses i should be looking at to replace any help or opinions would be great
Looks like the picos on your board are pink ones. There's one right at the bottom of the pic 2 inches from the right. Another is directly above that about 2.5" next to the screw on the heat sink and so on. Check them for continuity, replace as needed. I only see those two on the pic. Yours is an different chassis from mine but there may also be picos close to the convergence ICs that you should check. What they look like, of course, doesn't matter-just the values.
Thats great, yea I know if they dont look the same its fine lol, but they appear to be 4amp fuses
The first one you pointed out in picture is "82K Ω FU 41T" and it seems to be blown (after checking continuity) , could I just replace that with a 5amp fuse? The new pico fuses I ordered are 125V 5amp 0.281" x 0.093"
The other one that has no continuity is the one left of the transformer, about 3" up from bottom left , it reads 6.8K Ω FU 40T, I guess to sum it up, I take it that those are the fuses resistance, does it have to be the same reistance?
Hold on. If it has a resistance printed on it then it's a resistor. Picos look just like resistors but they have only one stripe around them. If there are multiple stripes then it's a resistor. I'll try to look at the pic again and zoom in on it. My eyes aren't what they once were.
Okay, I zoomed way in and those are definitely resistors. I don't see any picos on the board. I'd go back to checking for voltage at the STKs and looking for fuses near them.
Ok soo I looked at it again today and concluded there are no pico fuses? ( this set was made in 1995). Just those glass ones, and there were two on the D board, one a 250v 3.15A fuse, I replaced it, and it seems to have helped ALOT ...the bow is almost gone if not it is gone..the only thing is the colors still dont line up..I dont know if its because the potemeters in the front (first picture) were adjusted and screwed it up? I put them back to what looked like normal factory standard, but what would you suggest.
oh I do have a full service manual in pdf format if you would like to take a look ...I found some stuff of converging in it, but its about inputing a grid pattern and frequency counting kinda stuff. I was just wondering if there were any faster soultions like auto focus?
There should be instructions on screen and focus control adjustments (the pots you were talking about). There is a sony convergence training manual that might help on this site. Can you move the cross hairs when you're in the convergence menu? If they don't move there may still be electronic issues.