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Discussion Starter #1
Hi all and yes this is my first post but have been reading here and flooding my mind with knowledge that I never knew I would need tell now!:reading:

1st the info on what I am working on:paddle:
Hitachi 50DX20B (analog)
Chasses HP 1X
Convergence went out:hissyfit: and replacing the STK chips
stock IC chip stk 392-110 ( one color will not adjust horizontally at all and is also in corners tilted a bit and no longer straight as in + but more like /
Low power resistor
rk42 = 2.7ohm 1W (blown)

Replacement parts I believe I need.
STK 394-160E
One RK 42 resister 2.7 or 3.3 ohms?

I checked out the board for any and all problems and only found that the RK 42 resistor is blown. Every thing other test out ohm wise good and or under magnification looks good as in solder joints. Any thing other I should check? I only pulled this board and left the other two in the unit. Have cleaned the gun tops and also the mirror and screen so after this fix I am hoping all is good to go. This is not worth any more service calls but is worth a few DIY goes before it is fully replaced. I am just trying to make it last tell we move in a few more months as then it stays and we go hopefully LOL.

Now to my question(s):help:
First off from all my reading I have not run across any info here on this set so I am assuming (I know what that normally dose to me:hide:) that the basics are the same as most of the older Hitachi's. If that is so then my older bad STK 392-110 chips can be replaced with the newer STK 394-160E with out problems. I base this on the info here and with other sources that state the 394 chips replaced all of the older 392 chips such as the 110, 120, and 150.
So is my thinking right and that the STK 394 -160e will work fine in the 50DX20B set?:praying:

Question number two and three are ones I am as clear as mud on. With the 6 low power resistors do they stay the same as in ohms as the 110 chips when replacing them with the newer 394-160E chips? My thinking is yes as there set to the circuit board and not the IC chip, this is also why Hitachi kits only come with the low power ones being the most likely ones to blow. I am right on this? :praying:

So to make it simple.
Will the stk 394-160e's work on the 50DX20B?
Do I need to only change the blown RK42 resistor with a stock value replacement of 2.7 ohms 1w one?
If the above is no on the resistor then do I need to change all 6 low power to the values in the kit per instructions even thou they are not for my chasse family? This is also some thing I do not believe is needed but I want to know rather then just guise.
I do have a down loaded service manual for this set just in case.
thanks ahead of time for your time and input.
Marty
 

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Be sure to read the first 10 posts in the thread below VERY carefully. If you have read it read it again, as I have just updated some of the information on the Hitachi kits.

http://www.hometheatershack.com/forums/diy-repair-maintenance/5600-crt-based-rptv-convergence-repairs.html#post43725

Get the right kit for your set based on the listings there and it will have the right parts. Use the resistors in the kit rather than what the service manual may say, as this is the correct info for the new chips.

Your post has been moved to a new thread in the proper forum to maintain forum organization.
 

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Discussion Starter #3 (Edited)
Okay 1 thanks for moving my post to the right area and sorry I had not posted it in the right place to start with.
I have reread the post in your link on the IC fix / upgrade kits.

there is no kit for my model or chasse numbers so I ordered the kit #X480295 it has the right IC chips but not the resistors.

so what I am wondering is should I keep the factory stock ones there and replace the one blown one with the stock value part (2.7 ohm) or as the kit labels it 3.3 ohm?
I would take it that if I change the one to what the kit says I need to change all of them to the kits specs.

Sorry for asking again but after reading that post over a few times it is still clear as mud to me but only on the resistors. from my understanding if the kit is not the one for your model or chase then leave them as they came from the factory and just replace the IC to the STK 392-160 from the kit and any burnt or blown resistors with the factory spec on the semantics.

Some times it is not fun having an older cheap TV being there simply not worth much later so no parts kits or any real info on them any wear to speak of. O well I have nothing to loose on this one if I fix it great if I do not one less thing to move.
 

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These are the resistor values for your chassis. Change any that are different and those that are heat damaged or stressed.

RK42 2.7 AT03199S
RK46 2.2 AT03197S
RK50 3.3 AT03202S
RK54 2.2 AT03197S
RK58 3.9 AT03204S
RK62 3.3 AT03202S
 

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Discussion Starter #5 (Edited)
Aw that’s what I was thinking:yay2: the factory stock values! there all in spec but the RK42 one. thank one is burnt / blown / open and will be replaced with a new 2.7 ohm factory spec part.
Thanks now it is clear as a mountain stream:jump:. Your help is great and your time has been welcomed and thank you for all you have done for us DIYers:clap:.
I try to do the same for others in my own areas of knowledge
Again thank you now onto the repairs! I will post a fallow up when done and that should be around friday next week.
you are so right about the cost of the IC chips being cheaper if bought in the kits vs. each.
I did have to add in the resistor for the one that is burnt / blown and will have all the kit ones as extras.
it still was about 1/3 less money and that is what DIYing is all about saving money and learning or at lest with me it is.
You da man!:yay2::jump::clap::jiggy:
 

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Discussion Starter #6
Well time for an up date. The fix with the new Convergence stk 394-160e IC's and replacing the burnt resistor fixed this set right up so thanks for all the help

Now a month later turned the TV off one night and the next day went to turn it on all I got was the red power light. Now it will not even g out. Tried using the remote and also the power button on set same thing light stays on. No Pic and no sound any Ideas?
 

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Do you get menus or OSD? Unplug and try again to reset?
 

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Do you get menus or OSD? Unplug and try again to reset?
I will be doing the unplug and replug thing when I get home. About the menus I was not there but the wife and kids said there was nothing at all showing. When they had it on watching it nothing out of normal happened. The next day when they went to turn it on that’s when it would not turn on at all and the red power light stayed on and would not go out tell the set was unplugged. When I get home check things out better and then post more as needed here. I was just trying to get a heads up as to what to look out for.
 

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Sorry for the delay in responding but this is things are at now.
I did the plug un plug and this worked. A new problem showed up acting like this one. I did finally get it all sorted out and it was the Dish network receiver. I have a two in one receiver analog and receiver one was going out so no pic on the big screen TV. Once this was found out I then replaced the receiver and now no more trouble at all with the TV or receiver going black or not turning on or off any more. I thank ya all for the help in this long DIY project but I believe its all finished now and I am posting this so any one other that comes along doing a search with this set will find it and be able to read both fixes that had ended my problems. again thanks for all the help it has been well worth the effort and the cost savings alone more then offset the frustrations of this, I must add my knowledge base has also grown much also in this project and in doing so I am on the look out for a free TV like this one with the same problem to fix and then give to my son so here’s luck on DIYing your own set!
 
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