I received a Panasonic PT47WX52F (chasEP824) TV that my friend gave up on. One of the convergence amps when bad so he ordered two new Sanyo STK394-250 and put them in but none of the convergence adjustments work. When I got the set and looked at it, I found that the modules are not turning on! The orginial modules were STK392-110. He said he found on the internet that STK394-250 was a direct (better) replacement on some HDTV site. I tried to get the data sheet on the STK394-250 but since Sanyo does not make them any more it does not exist. I did find a crude block diagram that shows Pins 2&3 as a mute circuit with pin 2 spec from -.5 to +7Vdc. The board has pin 2 grounded and pin 3 goes to the collector of a transistor that looks like it gets turned on only when the b+ starts up then is off. It looks to me that I need to run pin 2 to a resistor to +5v to turn the modules on. Does anyhave a schematic of any TV that uses the STK394-250 so I can see how it is implemented? I would just need the circuits around the 2 STK's. The internet shows that Mitsubish:
CHASSIS: K20
MODEL: WT-42313 / WT-42315 / WT-42413
CHASSIS: V22
MODELS: WS-48313 / WS-48413 / WS-55313 / WS-55413 / WS-65313 / WS-65413
CHASSIS: V23
MODELS: WS-48513 / WS-48613 / WS-55513 / WS-55613 / WS-55813 / WS-65513 / WS-65613 / WS-65713 /
WS-65813 / WS-73513 / WS-73713
CHASSIS: V24
MODELS: WS-48315 / WS-55315 / WS-65315
CHASSIS: V25
MODELS: WS-48515 / WS-55515 / WS-55615 / WS-55815 / WS-65515 / WS-65615 /WS-65815 / WS-73615
uses Th STK394-250 & the Hitachi 57H83. I would appreciate any help!!
regards,
Geode
no somthing is wrong, the upgrade replacement is stk392-150 that ic he used is a diffrent animal. only replace stk392-110 with stk392-150 or stk392-180 these work fine.
Thank you.
I found that out also, but I would like the information on the STK394-250 since it is new and already in the set. It looks to me the same thing but with a different mute circuit that operates a bit different. I would still like to see an implementation of the STK394-250 in some set.
regardsl,
Geode
UPDATE
I tied pin 2 to 3.3v and the modules turns on and works great!!! I did not even have to converge the set beyound the customer convergence adjustments! The picture is great!!
I would still like someone to send me any schematic of a TV that uses the STK394-250 just to see how the mfg. do it.
regards,
Geode
That is a dangerous thing to do man. Modifing a circuit could be a fire hazard. Hope the TV set does not burn up and hurt someone.
Larry
I am an engineer that has designed many IC's in my day! I know what I am doing. Tell me how drawing <.5ma from a regulator is a fire hazard? Did you even look at the circuit before making such a Wild Claim or are you just trying to act smart?
regards,
OK, someones a bit touchy here? I am just stating a fact, it is not wise to JURY rig a TV set. You can certainly do whatever you want, as long as you can live with it. Also, where does it say anywhere in your post that you are an "engineer"? Bottom line, that TV set was not designed to use that IC, and will probably overload the convergence coils or a related component. There is a lot more involved then just the mute line you modified and jury rigged the IC to work.
I always upgrade STK-392-110s ,with STK-392-180s they are better IC and they do hold up!
DOES anyone know service menu for panasonic PT51HX40b chassis BP819 need to realine convergence if you have factory menu Please send e-mail to [email protected]
Larry
How can you make such a Foolish statement like:
"Will probably overload the convergence coils or a related component"
Have you done an analysis?
Well I did!!
I have the two specs from Sanyo! The new Ic is superior in every respect!! It even runs much cooler!!
Instead of just making up absurd wild comments, you could have done an analysis or ask questions to learn something!! I thought that was the purpose of sharing data on this site!
Can I now make an absurd comment about how you work?
regards,
Geode - we don't know who you are here, i don't see allot of engineers on this forum. What larry said is good advice for a novice, he does not have to look at a schematic, the fact that a perceived novice altered a circuit design is dangerous, you may have diverted less than.5ma but without looking at the schematic, that .5ma circuit could be controlling a circuit with the capability of producing a fire hazard. If you are an engineer as you claim. then that is fine you should know and take responsibility for the circuit design. but i would not recommend any circuit changes unless it was authorized by the manufacturer. I certainly don't want to give any advice that will damage someone else’s tv or produce a hazard. I have worked with and respected many engineers before, but when they design a circuit, an exhausting series of tests are preformed in order to ferret out the errors in the design. Even with something as small as what you had done, I know as the lab tech (which I was at one time) would have conducted a series of tests to prove the circuit before we would submit it to UL for approval. Every in-production circuit change has to go though this process, no matter how much you think you know. Or how small the change was. I remember once we changed an earth ground screw down point. To a location on the other side of the chassis. We had to run a week’s worth of tests before it could be approved.
zapdbf
I agree, but he can ask questions to find out experience,background,etc. rather than make such absurd comments. Shoot first then ask questions?
regards,
geode, what's with the hostility man? OK OK I am not an "engineer". But I have just about 40 years experience, THAT'S why I can say this. I cannot count how many so called "engineers" have tryed to repair their own TV sets and have brought to me because they thought they knew it all. This is a nice community and we do not need the hostility or the insults. So if you cannot say anything nice or ask in a professional matter, please refrain from saying anything?
Geode,
Thanks for the tip on the 394-250, I'm replacing the Convergance drivers in a couple Hitachi sets. The 392-110s don't really seem adequate for HD use, the spec sheet only rates them for SD.
Brian