Hitachi & Other Manufacturers Convergence Problems (STK392-110 ICs) Read Post 1

[robert8450]

Is there any chance that someone here might have a service manual for a 53udx10b ? if so, can you please send me the pdf and I'll gladly paypal you something for it.

Otherwise, can someone priovide a link where I can buy one for less than $20 ?

I just got a "rough estimate" from the local repair shop here in Grand Rapids and it was around $400 + a fee to come get the TV - they would not allow me to just bring in the convergence board. Anyway, since I know which end of a soldering iron to hold onto and have replaced a resistor and transistor here and there over the years, I thought I'd give the repair a whirl myself since there is such good info here on this thread.

This PCB has been repaired before (not by me) and has a jumper wire installed from pin 1 on one of the amps [(stk392-110) IK04] to a nearby diode (dk25)... has anyone seen anything like that or know anything about this?

I suppose the service manual will provide some input on it, but was just curious about what you guys think, since it is definately not a factory jumper.

Sorry to ramble, but one more thing. I went ahead and ordered the repair kit with the stk392-150 amps and resistors (should be here in a few days) because that "appears to be the prefered choice" from reading this thread... BUT, if that is the case, then why are the stk392-110 amps still listed in the first post? I mean if the 150 amps with new resistors is better, shouldn't we just go that route? Now I'm sitting here wondering if i made the right choice. I say that becuase the repair shop said they would use the factory original stk392-110 amps... ??

[Paul1958]

Robert, I would bet this is a "field repair" from the service done before. Most likely when they unsoldered the old chip they destoyed the "land" or interconnection between the two components. If you look carefully, you may be able to see where the copper connection on the circuit board is broken or missing. The manual will only verifly that there is an electrical connection between the two components.

I also considered updating to the 150's. However, my intention was to repair the TV and only replace one defective AMP if possible. The less soldering you do on a cicuit board, the less chance of causing addional problems like lifting and breaking the interconnections on the board.
My advice is to use as low a wattage iron you can get away with and a fresh piece of Solder Wick. I prefer using fine braid around .075" wide.

[robert8450]

thanks for the input Paul but I looked for that and don't see anything to suggest that they broke the imprented copper - this is clearly an added jumper for an "unknown reason".

[galiath]

I have a hitachi 43fwx20b and 3 of the resisters are burned I cant tell the color on them, they are the rk53, rk54 and rk58 resisters on the convergance board, also a link to a good site to order these parts. I already have 1 of them which is 2.70hm @1 watt I think this one is the rk53 but not sure, should say I cant remember I had to change the same resister and the 2 stk392-110"s on my other tv about 3 month"s ago, if any 1 has either the part #'s or the values of these resisters could you please post them, it would be much help! thank you!!!

this fourm has saved me much time and headache, 57 has alot of good info in here, as well as others.

[Paul1958]

I wouln't be too concerned about it. Just wait for your new Amps and resistors and take your time and put them in. Good luck and let us know how it works out!

I can see that I'm now going to be addicited to a Covergence IC Forum- I think I'm going to need professional help!

[kctxau]

Well, Along these same lines, I had replaced a set of stk392-110 amps on a 53wdx10b with -150's. They lasted 9mos. Originally, the set developed the typical convergence alignment problem, replacing the the amps (and resistors)with the 150's fixed the problem. Now, 9mos later, the tv only flashes the power light and R54(150ohm) is burnt/open. I replaced the amps again with with 150s, and the burnt resistor. The tv began to come up (no flashing power light, hv is coming up etc) then, within 60 seconds, an audio thump is heard, and now a flashing power light again. All of the resistors on the amp board are good (measured out of circuit). The deflection (Flyback) board components appear to check good also. Do these amps have a history of immediate failure, or am I still missing a shorted(or open) part? The front of the amp markings are stk392-150 with a 4f12 code(or similar), the back has a green stamp of 392150edb5.
I'm doing this as freebee for a friend(parts included), but I can't afford to just keep replacing $30/set parts just to watch them burn up.
Any help is genuinely appreciated.
Thankyou, for your time and your help.
Keith

[57]

The ICs will fail immediately if the resistors or something else on the board is amiss. This is discussed in post 1 of this thread.

[kctxau]

Thankyou 57 for the reply.
As stated in my post, all resistors on the board check good. These were all measured with one end unsoldered from the circuit. None of the transistors are shorted. This is why I was curious if anyone else had problems with the amps when the rest of the circuit tested good. Maybe I have missed something, (certainly a possibility!). Its difficult to determine, when everything else 'appears' to test good, but the amp(s) blow within 60 seconds. I unplugged each of the amp connectors at the board
one-at-a-time, powering the set back on after each connection was tried, but the power light flashing continued.
Again, thankyou for your time and your help.
Keith

[kctxau]

Well, I'm embarassed to say, although all of the replaced resistors are good, I used the wrong value for R54. R54 should be 1.5 ohm, I installed a 150 ohm instead. That would appear 'almost' the same as an open resistor in that circuit, and blow the amps again.
Thankyou
Keith

[toddndeb]

My Hitachi 43UWX10B appears to have bit the dust for the second time in a little over a year and a half. Back in October of 2005 I had the Convergence Amps replaced for just under $200 and all was fine. I noticed when turning on the tv last night, it appeared to have a double picture & any text was very blurred. The color was a bit off, but didn't seem as bad as the 2005 trouble I had. This morning when I turned the set on, the picture lasted about 5 minutes (still blurred) and then went out. This was followed by the smell of "electronics burning" and the power light blinking on and off to the tune of what sounded like crickets chirping! I am thinking of just giving up all together & getting a LCD instead. I hate to put several hundred dollars more into fixing it again. I am cluless when it comes to doing any repairs on my own. Would anyone out there have any suggestions as to how to get rid of this set? Should I just pitch it? or is there a dollar amount I could try & get for it in the local Pennysaver? I don't know if it is worth the bother to try & "sell" it, but I hate to have spent $3,000 5 years ago only to put it out at the curb. Everyone in this forum has been great and always helpful! I appreciate any insight you can give.

[57]

I doubt you'd get much for a non-working TV like this. The best you might hope for is for someone to take it off your hands to use for parts...

[halmc]

After putzing about in DCAM mode on my 53UWX10B, when I attempt to enter magic focus, I encounter a screen of 9 '+'s. Clearly showing that my red color seriously needs convergence. It would really be great if I could adjust convergence from this screen. Can I? If not, how do I re enter the convergence grid? Thanks

[halmc]

Sorry, I should have asked several other questions. Yesterday AM I'm watching my 53UWX10B and without warning, I get a red shadow of sorts on the right hand side of the screen. The left side is OK, but as one looks across the screen from left to right, the red shadow gets worse, so I immediately suspect convergence, and discover this forum and thread.

I manage to get into DCAM and find that I cannot adjust the red in some cells, but easily can in others. Indeed, I can move the red like vertically in all cells, but can't move it horizontally in some.

Anyhow, after putizing around with it in DCAM, I find that I have completely eliminated the convergence issue in the general center of the TV, but have exaggerated at the horizontal extremes. I figure I could correct that if I could just get back into the DCAM mode, but when I attempt to enter it, I get a screen with a number of Pluses -- eighteen of 'em -- counted this way: nine for the ones that are composed of green and blue and an additional nine each of which are red, and somewhat displaced from the green/blue boys.

So essentially where I'm at now is when I attempt to enter DCAM -- by pressing the 'magic focus' button, I get these pluses.

What I do now?

[57]

The + are called Static Mode. You need to open up the front of the TV, removing the speaker panel (pull towards you) and access panel (Many screws - beware of wires connected to panel). Near the left side of the chassis (when looking from the FRONT of the TV) is a little blue button. You need to press this little blue button (hard to find) to get out of static mode.

You can then do a DCAM convergence, however, it sounds like your ICs are shot and need to be replaced as discussed in this thread. Various resistors and the board itself could also be shot. See post 1.

[halmc]

Thanks, 57, for the tip on the little blue button. Your idea that the amp is blown sounds reasonable. In fact the question I really had in mind, was this: given that I can't adjust the convergence in many 'cells' (is that the right word?) is that indicitive tha the amp is defective, plus some resistors.

I've read this thread pretty carfully -- it's full of information, but I don't think I saw the value of the resistors that fail. Did I miss it somewhere? I'll order a couple of those amps -- they're really cheap! But would like to get the resistors on hand too.

BTW, can one adjust the convergence with the set in 'static' mode?

Thanks again.