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What's the name of this capacitor?

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eagle1109

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Hello,

I have small pink capacitors which look like resistors in CRT TV.

Capacitor.jpg

I tested one yesterday and it was broken. So, I want to order replacement capacitors.

Now, what's the name of this capacitor?
Is it OK to replace it with ordinary ceramic capacitors?

Regards,
 

Why do you think it is a capacitor? Usually the pcb is marked "C5" or a number beginning with the letter C. Why did you pick ceramic? Is this one 22k pF? 10%? 100V?
 

I agree, that sure looks like a 22K resistor. 22,000 ohms. Probably 1/4 watt.
 

I'm working on CRT TV, this picture from google. It very similar to the ones on the PCB.

They are marked as capacitors on the PCB numbering system, and also on the schematic diagram.

Also, I tested it as capacitors test and they charge like capacitors.

And there are yellow ones too.

What's the name of this type, so I can search for it and see if I can find it on Aliexpress.
 

Obviously the photo is not yours.

Big Trak Brains and Brawn

It would be helpful if you were to post a photo of your actual device.

They tended to be ceramic capacitors manufactured in the 60's through to the early 80's.

It would probably be easier to replacement them with the current available ceramic capacitors.


BigDog
 
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    eagle1109

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Thank you very much :)

At the link it's called old axial capacitors.

They are not even available at Aliexpress!

WOW .. they are so old!

I find them on the current CRT TVs in the workshop.

They are mounted on the HIGH-VOLTAGE area of the SMPS, LOW-VOLTAGE area and probably the rest of the PCB.
 

eagle1109 said:
WOW .. they are so old!
Click to expand...

Yes, they quit manufacturing them about 35 years old.

You can replacement them with one of the modern today equivalents:

ceramic-capacitors.png

However, you will need to determine the value of the original part.


BigDog
 
Yes, the values are provided with the schematic diagram.

My question is why they used this kind of old ceramic capacitors with relatively modern CRT monitor?
The models I have in the repair workshop is like this one.
4894654_2.jpg
 

CRT TVs did not change much for many years. I had a TV like that one about 30 years ago. I never looked inside it.
 

I don't think this kind of CRT monitors are that old, 30 years is too much!

If you say 10 years, then I would accept this number because LCD, Plasma and LED monitors are on the market for quite years.

I think the LCD started to come out before 10 years. So I think 1990s was the time of CRT monitors.


My question is what they used 35 years old capacitors on 10 years CRT monitors?

Did they manufactures these capacitors before 35 years and kept them in electronics parts warehouse, then sod it to CRT manufacturers? Or the technology the these capacitors is old, and they manufactured the capacitors in the 1990s around the time of manufacturing the CRT monitors?
 

eagle1109 said:
I think the LCD started to come out before 10 years. So I think 1990s was the time of CRT monitors.
Click to expand...

Actually, the 1990's where the beginning of the end for CRT monitors and the beginning of color flat screen monitors.

In the late 1980's Pioneer had offered a 14" color TFT-LCD TV. By the mid 1990's 15" Color Plasma TV were available for $300.

Color flat screen monitors for computer systems first became commercially available in the mid 1990's.

Silicon Graphics Inc. (SGI) first shipped their 1600SW 17" TFT-LCD flat screen monitor for SGI 320, 540 and O2 IRIX Visual Workstations in 1998 at a cost of $2500.

By 2002/2003 TFT-LCD monitors out sold their CRT counterparts.

eagle1109 said:
My question is what they used 35 years old capacitors on 10 years CRT monitors?

Did they manufactures these capacitors before 35 years and kept them in electronics parts warehouse, then sod it to CRT manufacturers? Or the technology the these capacitors is old, and they manufactured the capacitors in the 1990s around the time of manufacturing the CRT monitors?
Click to expand...

The Chinese and others were still producing CRT based TVs and monitors into the 2000's. As Audioguru stated, the technology of CRT TVs has change little in the past 30 years or so, it's conceivable that the same system boards were used for the past 20 to 30 years. China and other countries have a reputation for continuing to produce components long after they have been discounted elsewhere. Case in point you can still purchase many ICs which were discounted by the original manufacturer from Chinese suppliers.


BigDog
 

Having been Mfg Eng Mgr at C-MAC we had many "Universal" brand thru-hole part stuffing machines that could handle these parts. We also had different adapters for larger axial parts and a different machine for radial parts in addition to many SMT lines.

My guess is the parts permitted those shops which only had one style of auto insertion handlers for the tape and reel mounted operation for lead bending, insertion, cutting and clinching of 0.3" body axial parts into 0.5" pitch holes. This makes it convenient for low cost manufacturing. These capacitors could easiliy have a large breakdown voltage , suitable for some CRT applications in a monolithic epoxy package, as opposed to larger value Multilayer ceramic caps, which have low voltage ratings<< 500V.

You can still get axial monolithic capacitors of any value and voltage rating, which is all you need to match. Unless it shorted out internally with signs of fatigue, I would not expect this part to fail. How would you classify it's failure mode? electrical or mechanical?

However you may choose a radial just as well as axial and most likely it will be an epoxy coated ceramic bead capacitor rather than a molded epoxy with a cylindrical body. Cost in high volume to purchase is about $0.005 but to buy one only is anyone's guess.
 
E-design said:
Switching supplies in TV's often go into a hick-up mode for protection if there is an excessive load due to a fault somewhere.
Click to expand...

I don't think there's an excessive load. There's might be a short in the LV area.
If there's a short at the HV area, I would get explosions.

BradtheRad said:
In line with post #2, hiccup mode is liable to drop the frequency down into a slower range, which could explain audible noises coming from the inductor.
Click to expand...

That's most what I think!

I have another working TV, and I desoldered parts of the LV area, to know what's the problem.

chuckey said:
Is the earth on the CRT, is could be a corona discharge due to leakge somewhere.
Frank
Click to expand...

I don't know what's the corona discharge.

SunnySkyguy said:
Having been Mfg Eng Mgr at C-MAC we had many "Universal" brand thru-hole part stuffing machines that could handle these parts. We also had different adapters for larger axial parts and a different machine for radial parts in addition to many SMT lines.

My guess is the parts permitted those shops which only had one style of auto insertion handlers for the tape and reel mounted operation for lead bending, insertion, cutting and clinching of 0.3" body axial parts into 0.5" pitch holes. This makes it convenient for low cost manufacturing. These capacitors could easiliy have a large breakdown voltage , suitable for some CRT applications in a monolithic epoxy package, as opposed to larger value Multilayer ceramic caps, which have low voltage ratings<< 500V.

You can still get axial monolithic capacitors of any value and voltage rating, which is all you need to match. Unless it shorted out internally with signs of fatigue, I would not expect this part to fail. How would you classify it's failure mode? electrical or mechanical?

However you may choose a radial just as well as axial and most likely it will be an epoxy coated ceramic bead capacitor rather than a molded epoxy with a cylindrical body. Cost in high volume to purchase is about $0.005 but to buy one only is anyone's guess.
Click to expand...


Thank you very much for the information.






>>>>>> Well, today I came from my weekend vacation.

I entered the workshop, looked again to the situation, and thought about the switcher IC in the HV area. It didn't have the 5V from the opto-coupler.

I changed the opto-coupler, measured the voltage on the LV area. Found a missing voltage, followed the voltage of the parts dealing with the opto-coupler voltage.

Found a broken zener diode, replaced it. Replaced also the feedback transistor Q830 as it explained on the schematic diagram.


Now, the CRT works partially, after touching different areas with the DMM.

The beam gun, shows a sign of over heating at the base of the cathode area.
It looks like overheating the wires of the valve until they go orange!

IMG_20160418_191844324.jpg
 

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