[ja]

kjčopi,

[Guest]

Dietrich, any of the caps that are in paralell with the horizontal output
transistor could be bad causing insufficient width, you may find that soldering the horizontal driver transistor or the driver transformer will
fix it, as for the vertical at the top you may have to change that diode
or adjust the vertical height/ size pot just a little, I don`t have a service
manual for your model as it is different than the USA sets so the numbers
you are giving me don`t tell me anything, sorry that`s all the info I can
give you, Larry E

Hey Tibor glad you found it, Larry E

[Guest]

Hi All!

Thank You for a help! My TV now working good.
I found a brown 1uF @50V capacitor behind a heatsink.
Now it's changed and I am very happy!
Regards,
Tibor

[dfahren]

Larry, thanks for the remark. I will check the connections of the ON4409 (horizontal output driver) and I will resolder the driver transformator (never would have thought of this one, really!) as you said.
As far as the cap of the horizontal output transistor is concerned, I think it must be the C416, 270pF, isn't it? There is another cap C463. It as an exclamation mark next to it which means it is a critical one. I think you don't mean this one, right?
BTW, I replaced C303 and C317 in my tv set and, voilà, the picture has fine linearity like on the first day. However, I notice at the very first inch on the top of the picture that lines are still widely separated. Do you think that some other component also suffered a failure like the zener diode D315, for example?

Cheers, Dietrich

[dfahren]

@guest who recommends to replace all caps of the vertical driver unit
Okay, I agree that might be the best option if you don't own any testers, ocilloscopes and the like.
No I didn't hear any pop. No electrolytic cap explodes. (You must be pretty nasty to those caps to get them exploded in an instant ... )
As you recommend, I will lean away all caps and resistors that seem to be very close to heatsinks (there are a few as far as I remember).
Oh my dear! Replacing all caps that are good for temperatures up to 85°C? Poooh, I want to see some programmes not actually the innards of my tv .... I will see to get high degree caps anyway. Thanks for the hint!
Cheers, Dfahren

[Guest]

Dietrich, this ones a little harder, check solder connections in and around the horizontal output transistor, resolder horizontal driver transformer,
(check with bright light and magnifying glass), if solder is good, replace the cap(s) off the collector of the horizontal output transistor, one side of
the cap will go to the collector the other side to the emitter (or ground)
these caps are usually not electrolytics but are generally low value
high voltage mylars, not polarized, (you can put them in either way)
good luck, Larry E

[Guest]

Dietrich, this ones a little harder, check solder connections in and around the horizontal output transistor, resolder horizontal driver transformer,
(check with bright light and magnifying glass), if solder is good, replace the cap(s) off the collector of the horizontal output transistor, one side of
the cap will go to the collector the other side to the emitter (or ground)
these caps are usually not electrolytics but are generally low value
high voltage mylars, not polarized, (you can put them in either way)
good luck, Larry E

[Guest]

I do not agree with Dfarhen, if you do not know what you are doing or do not have a tester for the capacitors, change all of them that are near the chips heatsink. (they are only a few cents each) Make sure the new ones are all high temperature (105 degrees C) Lean them away from the heatsink before soldering and do not get them too hot.
An electrolytic charged in reverse will explode (did you hear a pop?) Now the electrolyte can leak out. I would replace it.
Some verticle heatsinks get very hot. On these, mounting the capacitor underneath the board may help.
Some cheap/older televisions are built with 85 DegreeC capacitors. If yours is like this have you considered replacing them all? You can do this for about half the cost of an ESR tester.

[dfahren]

Larry,
maybe you can also help me on this one ....
I notice that the width of my TV picture has become wider in the last year. Maybe it's also a capacitor problem, maybe not, I don't know. Unfortunately, my Toshiba 2100TD only has a potentiometer that, when turned, affects the position of the complete picture on the screen. So turning this potentiometer shifts either shifts the picture a bit to the left or to the right. I would like to know if there is some resistor that can be replaced by a potentiometer so that I can change the width of the picture.
Thanks for you help. It's always highly appreciated!

Cheers, Dietrich

[dfahren]

Hi there Larry and Tibor,

last night I repaired my Toshiba. Larry, you are completely right, the defective cap was a brown one. Its name is C303, has 2.2uF with 50V, which might be too little for our 230 Volts. So I replaced it with a 2.2uF with 63V. The new capacitor didn't have a mark I know for the minus pin. So I tried it both ways. Guess what happend ... Yep, the TV shot down the instant I switched it on. Not very amusing. But Toshiba builds its TV sets with a TDA4601 that switches off the TV when it notices something is going wrong. (At least I think it's working that way.) So I resoldered the cap and, yep, my TV is up and running again and is working like a new one! That was great!
Sure, Larry, if my TV set had had more severe problems like some IC is defective or some special component had needed to be changed, I would have given it to some technician. But since I needed to change just one cap, I decided to do this on my own because last time I paid for this more than $130 (110 Euro) and then I would have invested more than $200 in a TV set that has no stereo, no up-to-date HF-tuner and the like.
Tibor, your Toshiba 2112DD seems to work differently than my Toshiba 2100TD. At least the circuit diagrams look pretty different. And I also think the way the vertical deflection is controlled in your TV is done differently than in mine. So I can't give you any hint as to which cap(s) you should change. Unfortunately, the circuit diagram you can download from this Web site has pretty poor quality. You can't even read the characters properly. 8-(
Nevertheless, when looking at the diagram, I can see four caps I think you should replace. These are 3300uF, 25V near the vertical position switch, the 1uF next to it (Voltage??), the 220uF (35V??) which connects to pin 8 of the LA7837, and finally and particularly the 47uF (10V??) which connects to pin 1 and pin 5 (via the 10K resistor) of the LA7837.
My recommendation is, first, replace one cap then check if the TV set is still working, then replace the next one and so on until you are done.
One last remark: It might be necessary to desolder (correct word?) one or more metal plates on the back of the board to get to the caps. Please also keep in mind, there are voltages up to 25KV in your TV set that can kill humans! At any rate unplug your TV set from electricity and make sure you wait a bit before you start to solder some component so that remaining charge can dissipate from caps.
I hope you will also get your TV set working back soon!!!!

Cheers, Dietrich