[DIYPatrick]

What kit is for model: 51UWX20B chassis: DP23? I know that I need 2 STK394-160 Output ICs, but don't know the values of the resistors. Can somebody please help?

 

[lcaillo]

If you have not read the convergence repair sticky, be sure to go through the first 10 posts very carefully. The info you need is in this post:

http://www.hometheatershack.com/for...based-rptv-convergence-repairs.html#post43743

 

[DIYPatrick]

I did read your first 10 posts. Thank you so much for all the info. I called Hitachi- They were able to tell me the 6 resistors in the locations on the chassis I need to replace. I found that kit X480293 had 4 of those resistors along with the 2 ICs. Now I just need to learn how to solder.
Another thing I need help with is taking the chassis out from the TV. I have taken everything off except some device (maybe 3"x3"x3.5") soldered to the chassis, that has heavy wires coming out the top going to the projectors. Is there anyway to diconnect the wires or something.

Thank you

 

[lcaillo]

You should not have to change 6 resistors. They only need to be changed if the values are different in the kit or they are open. Most sets require no more than a couple of resistors, if that.

You do not need to remove the entire board. You can stand the entire chassis up on the front edge once you loosen a few wires. The large device you describe is the high voltage transformer, aka flyback, and it does not need to be removed. Taking the wires out is a challenge and if you don't get them seated or if you break a clip on the end you will have a much more costly repair. Leave it alone.

 

[DIYPatrick]

Kit X480293 [Ohm] My Chassis [Ohm]
RK42 3.3 3.3
RK46 1.8 2.2
RK50 2.7 2.7
RK54 1.5 1.8
RK58 3.9 4.7
RK62 2.2 2.7

I thought that I needed to replace the resistors in my chassis to make sure they were ok. Are you saying that the resistors in my chassis need to be replaced with the ones from the kit? The kit isn't for my tv- Why would I put different resistors in my chassis that aren't for my tv?

Thank you for your continuing help.

 

[lcaillo]

A few of the sets have slightly different values in the kits than found in the sets originally for one or more of the resistors. Most are the same, and the original values still work. The resistors should always be checked and compared to the value in the kit for your set IF there is a kit for your set. The .pdf files for most of the Hitachi kits may be found at the link above, and they should be used for reference. As noted in the convergence repair thread, any damaged or open resistors should be changed, or any that have an updated value should be changed.

 

[DIYPatrick]

I'm still confused- The kit is NOT for my model tv. I'm just using it because it includes four of the same Ohm resistors that my chassis originally came with. If the Ohm's of the resistors should be change from original values, what should I change them to?

Thank you for you help.

 

[lcaillo]

In post number two, I linked you to the post on buying the parts. In that thread are .pdf files of the service bulletins that come with the kits. There is no specific mention of your chassis and your set, so assume that the original values should be used. Verify the values in the service manual. Don't make it more complicated than it is. If there is not specific info that says change the parts to a different value, the original values should be fine. Changing parts that are not necessary is just asking for problems, either by making a mistake in value or in desoldering/soldering. Verify your values and your work by double or triple checking them.

Be sure to get all of the wires back where they were, both in terms of connections and routing.

 

[ljryjj]

You'd better get a service manual for your TV. With that you'll see the resistor values, and most likely you need the instructions in it to do service mode digital convergence adjustment.

 

[DIYPatrick]

I will get the manual, but I already called Hitachi and got the resistor values for my tv. Will the manual tell me that since I'm now putting STK394-160E's, that I need to replace some of the resistors?

Thank you.

 

[lcaillo]

It will tell you what you need to know to align it.

 

[ljryjj]

lcaillo already said that you only need to replace defective resistor if any. STK394-160E is a direct replacement of STK392-110, aka, no resistor needs to be replaced unless defective.

 

[lcaillo]

lcaillo already said that you only need to replace defective resistor if any. STK394-160E is a direct replacement of STK392-110, aka, no resistor needs to be replaced unless defective.

That may or may not be true. It is for Hitachis, but there may be differences in the muting circuit that is not a problem in the hitachi sets. Sanyo never published a datasheet on the -160 so we really don't know if there are differences or not. I have heard of some other brands that have had problems using this sub. There may also be other reasons that they muight change resistors, like learning that a particular value allows for more efficient operation in some way. I don't know, but I never assume anything and I always check.

The bottom line is, assume nothing, check everything. Then verify it again.

 

[ljryjj]

Sure master lcaillo! For Hitachi it should be ok.

This reminds me a saying from Eric Bogatin in his signal integrity class: it depends.

:yes:

 

[lcaillo]

The correct answer to most questions is "it depends." I even once had this as my signature. When you make sweeping assumptions and generalizations, you are almost always going to be proven wrong at some point. Especially in this industry.

 

[DIYPatrick]

A friend at school told me about "wire wrapping" to fix the pins to the board since I have never soldered before. Is this an option?

Thank you.

 

[ljryjj]

I don't think wire wrapping is a feasible solution for this repair.
You'd better ask a friend who is good at soldering or resort to a service tech. This DIY project is not suitable for people without basic hands-on skills.

 

[DIYPatrick]

I'm definitely hands-on. I will practice!

Thank you for your help- Your good.