Steve's KP57WS510 Project

Hi Guys,

I just picked one of these units up. I wasn't really in the market as I'm pretty busy right now but it was just too tempting - literally the conversation went like "we're moving tomorrow and we're NOT moving a big, heavy, broken TV - come and get it"!

I picked it up but had to store it in my folks's garage as I was already working on a 51" set of the same model for a friend (these things are kinda like cars, there's just so much parking space available! ;->).

I have the 51" fixed and it's off to it's new home so this one will be finding it's way over here shortly so I thought I'd start a thread on the project.

The owners said they had it looked at and it was a convergence issue but they couldn't afford the fix and they did describe what a convergence problem looks like. I haven't fired it up yet so I'm not 100% sure it's a convergence issue -> I learned a long time ago that when you service stuff confirm what it's doing for yourself before you start!

I'm just gathering information for the project right now and am just assuming it's a convergence issue.

I found a service manual at this link (scroll down to find it):
http://www.techlore.com/group/2/list_downloads

It doesn't have the schematics with it though, if anyone has a link to the schematics please post it for me.

Doing a little research on this series it seems the following are the common failure items in the the convergence circuit:

(2) STK392-560 Convergence ICs

I noticed that Acme does have the STK392-560s. They also have the following:

STK392-570 Imitation
High quality Chinese imitation
We guarantee these to be as
good as the original Sanyo ICs

Also replaces STK392-560
90-day Warranty
Mitsubishi # 267P150010

I've read a few posts at various places on the net that recommend the 570s over the 560s as the 560s are 5 amp rated and the 570s are 8 amp rated and are compatible for use in 560 circuits (and I note that Acme even says "Also replaces STK392-560"). I noticed that Leonard doesn't have that sub noted in the convergence repair sticky though, so I gotta ask . . . What's the move here, real Sanyo 560s or imitation 570s that Acme is putting their reputation behind and claiming are as good as the Sanyos? Have the 570s proven to be a viable sub for the 560s?

(2) 5 amp, 90V IC link fuses

PS5001
PS5002

These are on the "G" board that stands vertically to the left of the "D" board that has the convergence ICs.
These are "IC Link" type fuses from the factory but pico fuses can be used.
From what I gather at least one of these almost always goes out.

(6) 3.15 amp, 90V IC link fuses

PS8001
PS8002
PS8003
PS8004
PS8005
PS8006

These are all located on the "D" board.
These are "IC Link" type fuses from the factory but pico fuses can be used.
I've noticed some use 3.5 amp in leu of the 3.15 as they are easier to find but Acme has the 3.15 amp ones so I'll stick with what was stock.
From what I gather these don't go out as often as the 5 amp ones on the "G" board but they go out often enough that they MUST be checked.

(30?) 4.7 ohm, 1/2watt, metal film, 1% resistors.

R8045
R8046
R8051
R8053
R8059
R8060
R8063
R8064
R8066
R8067
R8069
R8070
R8073
R8075
R8078
R8079
R8081
R8082
R8085
R8086
R8089
R8090
R8091
R8092
R8093
R8094
R8097
R8098
R8105
R8106

It seems from what I've read that burnt resistors are not as much of a problem on these sets, the bigger problem is blown IC link fuses. Do I take it that those fuses usually blow fast enough that they usually save the resistors?

I can't find specifics on which resistors commonly fail, all I've found is some posts where people have made the STK & fuse repairs and are still having problems - they are usually directed to "check the resistors near the STKs". A couple posts I found though did mention 4.7 ohm, 1/2 watt resistors as the ones to check (but didn't list their parts designations or quantity). What I've listed above are the 4.7 ohm 1/2 watt resistors I found in the service manual under the "D" board parts listing. Again, schematics would be nice if anyone has any.

The 4.7 ohm 1% resistors are kind of hard to find too - they spec 1% tolerance and I'm assuming there's a reason for that so I'd like to adhere to it, finding 1% tolerance in this ohmage and wattage is not easy though! I imagine one could go up in wattage, though I don't like to. I suppose if one couldn't find any 1% tolerance they could buy some 5% and just use an accurate meter and select the ones that were within 5% tolerance (i.e. between 4.65 and 4.75 ohms).

Does anyone have any input on the resistors? There are some lower value, fairly high wattage resistors on the "D" board listed in the manual - do they need ohm'd out too?

The only other thing I see that's a bit different than the other convergence repairs I've done is that the flyback transformer that supplies high voltage to the hv block is on the back of the board that has the convergence ICs. I just recently unhooked some HV cables doing a repair on a Sony so I'm confident I can unhook the hv cable without damaging it, but I'm also taking note that Leonard and other techs on other forums have posted they don't mess with unhooking and potentially damaging the hv lead, they just uhook everything else and then carefully flip the board over and work on it in the set so I'm going to follow their lead and attempt to do the repair in set (I'm picking up that there's enough of a risk of damaging the hv cable that it's best to not mess with it unless you have to - even for an experienced professional). If it proves to be too uncomfortable for me then I'll unhook the hv cable and remove the board so I can work on it more comfortably (I really like working at my nice comfy work bench rather than squatting on the floor!), but the plan is to try to put up with a little discomfort and save me a potentially self-inflicted problem.

As I work on the set I'll try to take pics and do some follow up posts.

Take Care,

Steve