KP-43HT20 convergence

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ed56
ed56's picture
hello, I'm new to forums -

hello, I'm new to forums - would also appreciate some advice. I have similar problems with this model. I have replaced the convergence STK ICs and one 5 amp fuse on the G board. I've checked the fuses/resistors under the heat sinks on the D board also. Still convergence issues - can't move red and green horizontal grid lines vertically in the service mode, blue works. I've checked resistors for continuity all seem Ok. However, there is one item on the "G" board that looks like a big resistor that I tested for continuity and appeared open. I checked the color band codes on the item but cannot correlate it to any resistor coding standards. The color sequence is: orange, red, green, white. There is no gold or silver band and the white band is definitely white.

zapdbf
zapdbf's picture
give me the reference number

give me the reference number on the board? also if you are having secondary trouble it is usually something wrong like missing plugs or bad solder, need to check this over carefully. Also re-check your fuses, because you can blow them again if you had a problem with the "D" board.

ed56
ed56's picture
I appologize, I've edited my

I appologize, I've edited my previous post.  The item in question is on the G board not the D. The location is labled R6015 - is this the reference number you asked for?  It fails a basic ohm test on the leads.  I've rechecked the fuses and will examine the solder points again.  Thanks for your response.

zapdbf
zapdbf's picture
ed56- i need one more thing,

ed56- i need one more thing, your model number

zapdbf
zapdbf's picture
that resistor is a 2.2 meg

that resistor is a 2.2 meg ohm, which is very high resistance. that is not your problem anyway.

Methodicly check the following fuses, make sure you have identified each one so you know you did not miss any of them. ps8002,ps8004,ps8006,ps8001,ps8003,ps8005.

Also check resistors r8122,r8127 - although in some models these are just jumper wires. if so no need to check them.

also at r8122 and r8127 with the tv on check the voltages at this point, they should be +22 and -22 respectively.

after  you have done this, post back here let me know results and we will move forward from this point

ed56
ed56's picture
I've tested all points above

I've tested all points above plus the voltages - all check OK, r8122 and r8127 were just jumpers.  One important item I did not mention before, the STKs I pulled out were STK392-560's, the TV shop where I got the new ones gave me STK392-570's.  He said they were suitable replacements for the "560's". Do you agree?

 Other items:  when in convergence mode I can adjust blue grids up and down, left and right.

                                                                                      green only left and right

                                                                                       red - can't adjust at all!

zapdbf
zapdbf's picture
I have never used stk392-570.

I have never used stk392-570. So i have no opinion. i am looking at the next step now

zapdbf
zapdbf's picture
What you said about movement

What you said about movement matches up perfictly with a problem with ic 8001 convergence ic.

ic8002 is working fine. pin 4,5, 12,17(ic8001) are the power supply pins check to see that they have continuity back to r8122,r8127 (jumpers)

pins 4, 12,17 will go to r8122 (sorry had it wrong)

pins 5,10 will go to r8127

now if the continuity is good, then you are left with few options as far as the problem is concirned, either all three control lines are bad (which is not pratical) or that ic is bad.  I would suspect the ic, before the control lines at this point because it is un likely that all three would fail at the same time.

ed56
ed56's picture
I've checked the continuity

I've checked the continuity as you stated above.  I did not get that arrangement.

I got continuity as follows:pins 4,12,17 to r8122 and pin 5 to r8127.  Both ICs were similar. 

zapdbf
zapdbf's picture
there were two revisions i

there were two revisions i looked at the wrong one(sorry), what you see is correct, and you are sure ps8001,ps8003,ps8005 are good, you now either have a control issue on all three geometric controls that that ic amplifies (which is a long shot), or the ic it's self is bad. I would bet the ic is bad.(IC8001)

zapdbf
zapdbf's picture
ic8001 controls the gv,rv,rh

ic8001 controls the gv,rv,rh

IC8002 controls the bv,bh,gh 

ed56
ed56's picture
It works! Thank you very much

It works! Thank you very much for your help and patience "zapdbf".  You saved me a lot of money just before Christmas - so my family thanks you as well!  It was related to IC8001.  Pin 2 was not soldered good enough.

Merry Christmas!  

severum
severum's picture
I just wanted to say thank

I just wanted to say thank you to Techlore and especially zapdbf. This thread along with the service manual allowed me to fix my KP-43HT20 for just the cost of 2 ICs and heat sink compound.

It was a lot easier than I thought it would be.

Wahoo!

mark714
mark714's picture
zapdbf PLEASE HELP!!!

zapdbf PLEASE HELP!!!
I seem to have a convergence problem with my KP-43HT20. We were watching tv and suddenly the colors were mismatched. I tried to use the coarse adjustment on the tv using the remote but could not get the images to match. I think that maybe the IC8001 and 8002 might be blown, but is there anyway to check that specifically, since I checked all the fuses on that board and on the power board like you had suggested and all were shorted, meaning they were not blown, so since everyone else had problems with the fuses, I am thinking that maybe my IC8001 and IC 8002 are not blown and it is something else. Any help would be greatly appreciated. Thank you!

zapdbf
zapdbf's picture
There is no way to

There is no way to specificaly check these ic's but, even without blowen fuses these ic's will fail. The circuit is relitivly simple and the only active devices besides the mute transistors are the stk ic's. replacing them will fix 85% of the televisions out there. with or without blowen fuses.

mark714
mark714's picture
So i replaced the ics and the

So i replaced the ics and the picture is still way out of alignment, so I went to course adjustment but everything I do on all three colors in in PJIC part, where you have blu, grn, red center, pin, lin etc. does not seem to do anything to the picture. the picture is bent inwards vertically and does not reach out to all corners, and all three colors although have similar characteristics are way off. What should I do next?

ron77
ron77's picture
There are 2 pico fuses on the

There are 2 pico fuses on the power supply board - 5 amp. If one of those is blown, the new IC's won't work

mark714
mark714's picture
where can i get the 2 pico

where can i get the 2 pico fuses, i tried radio shack they dont have those style of fuses.

mark714
mark714's picture
i tested both and only 1 of

i tested both and only 1 of them is blown the 5001.

ron77
ron77's picture
1 will do it, MCM or go to

1 will do it, MCM or go to your local tv repair shop. They will stock them and probably sell you one if you can't wait.

zapdbf
zapdbf's picture
replace the blowen one, you

replace the blowen one, you can get them from mcm electronics. or thepartstore.com

mark714
mark714's picture
So, I replaced the blown fuse

So, I replaced the blown fuse 5001. Now the TV will not turn on at all. During replacing the fuse I forgot to turn off the power at first when pulling the power board out of the back of the TV and got a little shock. Could I have blown something else? I have checked all four ps fuses on the convergence board and the 5001 and 5002, as well as the 1 glass fuse on the power board and all show shorted. Now when the TV is plugged in there is no standby light on and when i press power the standby light blinks 3 or 4 times and then goes off again and there is nothing output to the screen. There are 3 glowing things that are at the bottoms of each of the three color projectors, and they are lit. Where should I go from here????

zapdbf
zapdbf's picture
It sounds like you did

It sounds like you did dammage the board, is it three blinks or 4, if it is 4 you may have taken out the vertical circuit, also make sure you plugged in the yokes.

mark714
mark714's picture
it blinked 4 times, how do i

it blinked 4 times, how do i check to see if this circuit is broken?? and what do you mean by yokes? i dont understand that terminology...

zapdbf
zapdbf's picture
The yokes are the coil of

The yokes are the coil of wires on the neck of the crt's (the glowing projectors) there are wires that need plugged in if they are not, you can get a 4 blink error. If you verify that the yoke plugs are in, then you may have blowen ic8003 or dammaged the 15 volt line. The fixes that are presented here are usaly common problems that tech's run into. but now you have a situation where you need to troubleshoot the symptioms to find the problem. you now need to make live measurements, you need to check pin 4 and pin 6 of ic8003 for the presence of -15 on pin 4 and +15 on pin 6. If you don't have these voltage you may have power supply problems that need fixed, if they do exist then change the ic. Also ic8003 could be loading down the ps so dis connectiong pin 4 and 6 before you test will give you a more accurate result. if you disconnect these pins make sure you measure the solder pad and not the pin it's self.

This is what i would have to do to fix this tv from this point. Get the above diagnostic, then move to the next diagnostic point.

mark714
mark714's picture
i cant for the life of me

i cant for the life of me find ic8003
if it is on the a board, most ic on there are listed ranging in the 300s.

mark714
mark714's picture
sorry found ic8003, but it

sorry found ic8003, but it only has 4 pins

mark714
mark714's picture
So magically everything

So magically everything started working, and we started to correct the course adjustment and have green and red working, when we tried to start altering the blue adjustment, which is way off, some of the course adjustment adjustments do not alter the grid on the screen, the ones that dont work are lin, size, skew, center. I have also noticed that the IC8002 seems to be running significantly hotter than the IC8001, both have industrial heat sink compound on them. What should I do now

brad148405
brad148405's picture
Hello, is this board still

Hello, is this board still active? I need some help with a KP-43HT20 convergence problem

zerobagz
zerobagz's picture
i just aquired a kp-43ht20

i just aquired a kp-43ht20 projection tv wiht a convergence problem picture looks clear enough just there are three of them in dif colors lol they say they just spent close to 600 to fix then it goes out again they went to a flat and give this to me is it worth fixing is it cheap etc can you help me i have an internet phone that is unlimited if nessicary

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