Sony KV-13M!0 shuts down about 1 second after turned on

[rfranzk]

So all the high power bits are working (you get flyback lines because you're directly setting the tube).

Personally I've never used a resistor - just stuck the meter on amps, and shorted the cathodes to ground (VERY briefly)

Try checking round IC301 now, with a scope if you can to check for any signals going in and coming out.

I looked up the data sheet and checked all ground pins have continuity to ground. Ref =6.43V VCC=8.88 on some of the others all I get is noise, I can't adjust V/div or Time base for good pattern. I am going to watch the video on Scopes for Dopes to gain a little knowledge and try again. I have a Tektronix 475 that I got used. I don't know if it is accurate or functions properly. It may take me a few days to get back .

Thanks again rfranzk.

 

[tvtech]

I work for a Sony main dealer, so I've repaired a LOT of Sony CRT sets over the years

My "right hand man" or "technician" if you want cannot even read a circuit diagram. Give him a diagram and you will find him trying to look clever....but the thing is upside down......

He is strictly "Monkey see, monkey do". I work with this on a daily basis. No wonder I am loosing my mind.

He considers himself to be a "deep thinker". Wise in the ways of the world.........

Seriously.....

That my friends is scary

I deleted his photo. No point in making a fool of an Idiot. Will not help him.

Just makes me feel bad. Cause I am supposed to fix him and not laugh at him. No matter the cost to me and my sanity.

Regards,
tvtech

 

[rfranzk]

So all the high power bits are working (you get flyback lines because you're directly setting the tube).

Personally I've never used a resistor - just stuck the meter on amps, and shorted the cathodes to ground (VERY briefly)

Try checking round IC301 now, with a scope if you can to check for any signals going in and coming out.

I was able to get some waveforms off of the chip and I will try to post photos as that is the only way I can think of to get something off the old scope into a digital form. Some of the patterns looked nice and clean and others not so much. Not sure what we are looking for.

 

[Nigel Goodwin]

You're looking for a video signal going in the chip, and the RGB drive signals coming out of it.

 

[rfranzk]

You're looking for a video signal going in the chip, and the RGB drive signals coming out of it.

Pins 3 and 5 labled Yin and Cin is high frequency something peaking at about 4 volts. Could not get a real pattern (1st photo) pins 10 and 11 labled DBin and DG in are .4 volt straight dc pin 12 DR in is 1 volt dc. no pattern just straight line. pins 16, 17, and 18, are sort of square wave short pulses with bottom line at 2 volts and upper line at 6 volts. (2nd photo) pins 20, 22, and 24 labled R out G out and B out are sort of squre wave with upper band at .4 volts. (3rd photo)

 

[Nigel Goodwin]

Make sure ytou have an input signal to the set, you can't trace the signal if there isn't one - a colour bar signal in the AV input would be a good choice.

 

[rfranzk]

Make sure ytou have an input signal to the set, you can't trace the signal if there isn't one - a colour bar signal in the AV input would be a good choice.

Thanks Nigel,

Is there a simple signal generator I can use, (Or build) to accomplish this? Would a connection to dvd player work ok? This should be input to the video input and not the tuner?

rfranzk

 

[Menticol]

View attachment 69718

He is strictly "Monkey see, monkey do". I work with this on a daily basis. No wonder I am loosing my mind.

Regards,
tvtech

After analysing the photograph I think I found the cause of your problem!!

I share your pain Tvtech. Most of my classmates are wanna-be fashion models that, besides of mastering the arts of makeup and gossip, don't know (and don't want to know) about anything else in life.

PS: Excuse me by the interruption Nigel and Rfranzk

 

[Nigel Goodwin]

Thanks Nigel,

Is there a simple signal generator I can use, (Or build) to accomplish this? Would a connection to dvd player work ok? This should be input to the video input and not the tuner?

A DVD player would be fine - while colour bars are preferred any signal is better than none, and you could always pause a DVD to give a stationary image (which is the main point in using colour bars in this case).

Yes, it should be input to the AV socket, as if you can't see any picture you couldn't tune the TV in anyway.

 

[tvtech]

After analysing the photograph I think I found the cause of your problem!!

I share your pain Tvtech. Most of my classmates are wanna-be fashion models that, besides of mastering the arts of makeup and gossip, don't know (and don't want to know) about anything else in life.

PS: Excuse me by the interruption Nigel and Rfranzk

Thank You Menticol . Man am I slow or what???. Great picture mod there too. Now I am confused....Heck, it's late here.

That was a great Chirp

Regards,
tvtech

 

[rfranzk]

A DVD player would be fine - while colour bars are preferred any signal is better than none, and you could always pause a DVD to give a stationary image (which is the main point in using colour bars in this case).

Yes, it should be input to the AV socket, as if you can't see any picture you couldn't tune the TV in anyway.

Ok, Using a DVD just displaying its on display (mostly stationary) I have video signals at pins 3,5, and 44,45 at a lower voltage. No change in outputs 20,22, and 24.

I took a closer look at the schematic and it traces the video signal (Should have caught that sooner) It shows a signal at pins 1 and 15 of IC 401. I have it at pins 2 and 15. I suspect pin 1 is tv and 2 is video in. Does this indicate a problem with IC 301??

Photo 1 is signal in Photo 2 is signal out. same at base of video transistors on C board.

Thanks. rfranzk

 

[Nigel Goodwin]

Try slowly adjusting the A1 control, if it's not adjusted accurately enough it may be entirely outside of the the chips control range, resulting in no picture.

Failing that, IC301 could be faulty?.

 

[rfranzk]

Try slowly adjusting the A1 control, if it's not adjusted accurately enough it may be entirely outside of the the chips control range, resulting in no picture.

Failing that, IC301 could be faulty?.

I can't find any reference in the manual to A1 control adjustments. Please guide me here.


If it is the IC I probably will not go any further. Thank You Greatly for your assistance as it was a Great learning experience for me.

rfranzk.

 

[Nigel Goodwin]

It's RV702 on the CRT base, it's labelled 'screen' on the Sony circuit.

If the voltage on pin 12 of the CRT won't adjust down to the lower end (300V odd) then R702 could be high or O/C.

 

[rfranzk]

It's RV702 on the CRT base, it's labelled 'screen' on the Sony circuit.

If the voltage on pin 12 of the CRT won't adjust down to the lower end (300V odd) then R702 could be high or O/C.

Thanks Nigel,

Pin 12 started at 575 volts and adjusted down to 304 at the bottom of the adjustment. No change in display. Do you know an inexpensive place to obtain IC 301. I probably won't proceed will likely harvest useable parts from this set for future experiments.

Thankyou again for your assistance. My background is automotive and I enjoy messing with electronics. It's all an opportunity to learn.

rfranzk

 

[Nigel Goodwin]

Do you know an inexpensive place to obtain IC 301.

Only as a spare part from Sony, if indeed it's still available?.

 

[rfranzk]

Only as a spare part from Sony, if indeed it's still available?.

Just for grins I went up on the voltage adjustment to check it out. At about 650 volts a picture would flicker, at 750 volts I get a pretty good picture that stays on for one second then goes dark for one second, and so-on. Is this maybe a leaky capacitor, or is it a problem with the IC ? What do you think?

rfranzk.

 

[Nigel Goodwin]

Just for grins I went up on the voltage adjustment to check it out. At about 650 volts a picture would flicker, at 750 volts I get a pretty good picture that stays on for one second then goes dark for one second, and so-on. Is this maybe a leaky capacitor, or is it a problem with the IC ? What do you think?

Quite probably the CRT? - the chip (like all 'modern' TV chips) continually adjust the grey scale, which compensates for the CRT ageing - but this only works up to a certain point, beyond that it's outside the control range of the chip. Having to increase the A1 voltage in order to get any response at all tends to suggest the CRT has failed.

 

[rfranzk]

Quite probably the CRT? - the chip (like all 'modern' TV chips) continually adjust the grey scale, which compensates for the CRT ageing - but this only works up to a certain point, beyond that it's outside the control range of the chip. Having to increase the A1 voltage in order to get any response at all tends to suggest the CRT has failed.

OK, well I will harvest what I can experiment with and again Thank you for your expertise. One last question or maybe I should start a different thread?

I am researching a handheld oscilloscope, something like the Fluke 97 or 98. I will probably have around $2k to spend. Do you have any recommendations or input?

rfranzk

 

[Nigel Goodwin]

For that kind of money you could get a proper scope.