Can I replace KME cap with Samxon GF cap?

[chth96]

Hello.
I have 29inch LG CRT TV,And Yesterday,Whenever I connect AC power cord to power outlet without switch on, I heard a sound like white noise, And When I switched on this CRT TV, It sometime displayed correctly But usually It won't last more than 20 minute and The screen begin to dark and It finally did not display at all for hours..
Today,I dismantled its plastic case and discharged the biggest capacitor(400wv 470uf) which still holds 250 voltage,and I finally detached PCB from cathode-ray tube.
I measured ESR value of most of caps in PCB with MESR-100 and I found that KME(25v 470uf) and SMS cap(100v 22uf) from Korea chemicon and RG cap(25v 220uf) from samhwa is not good which is very close to STR-S6707 switching generator.
Especially ESR value of RG cap is higher than 100 ohm.
Currently I have some of samxon GF caps,So I browse through KME and RG and GF datasheet which I attached and I found that Although, Maximum ripple current of GF cap(105 degree Celsius,100kHZ) is higher than that of KME and RG and SMS caps,But Maximum ripple current of KME and RG and SMS cap has different frequency rate(120Hz)
But Is it possible to replace KME or RG cap with samxon GF cap even if It has different frequency rate(100Khz) in Maximum ripple current specification and Lower impedence?

[momaka]

Yes, it will be fine. Most CRT TVs use general purpose 85C caps, so any 85C or 105C general purpose caps or any low-ESR caps will be fine. Samxon GF is entry-level low ESR, so it will work... though I can't really highly recommend Samxon GF, since it is known to be a problematic series. But chances are, it should still give you more than a few years of useful life on that TV, so go for it.

BTW, it might also be a good idea to double-check the old caps with the ESR meter once you remove them from the PCB, just in case, as sometimes in-circuit measurements can be inaccurate.
I suspect you may find more bad caps (especially the smaller ones) if you really go dig through the rest of the board. The small ones just tend to dry out after a very long time, whereas the bigger ones usually tend to hold up OK if they were decent brand and series.

[chth96]

Thank you very much for your rapidness reply.
By the way,It seems that Samxon GF has different frequency rate(100kHZ) for Maximum ripple current and Low impedence specification.
https://www.mediafire.com/file/fhe8h...ries_.pdf/file
https://www.mediafire.com/file/wwiil...eries.pdf/file
https://www.mediafire.com/file/se2po...AMXON.pdf/file
Is it OKAY to replace 105 degree Celsius capacitor with any Low impedence caps like samxon GF series?

[momaka]

By the way,It seems that Samxon GF has different frequency rate(100kHZ) for Maximum ripple current and Low impedence specification.

Yes, low impedance / ESR caps are usually specified at 100 KHz... which simply means they will do OK with both high frequency (100 KHz or more) circuits as well as low frequency circuits (120 Hz.)

Is it OKAY to replace 105 degree Celsius capacitor with any Low impedence caps like samxon GF series?

Yes, will be fine.
Most SMPSes are better off with low impedance caps anyways.

[chth96]

I replaced all of bad caps and I also replaced another SMS capacitor 160v 2.2uf from Korea chemicon with Rubycon YX which is very close to D1879 transistor.
Is it no harm to replace with capacitor without ripple current rating? - Badcaps
I assembled CRT TV's PCB and plug into all of appropriate connector.
When I connect AC power cord to power outlet without switch on CRT TV, I noticed there is no a sound like white noise any more,and When I power on, I heard the ordinary startup sound like popping noise, But It won't display any screen at all only black screen,and It won't power off.
I already checked that capacitor is correctly soldered by measuring resistance between all pin of replaced capacitor and pin of any ic which is on the same trace in pcb.
I don't know why It won't display at all even I replaced all of bad capacitor...

[momaka]

Either you have more bad capacitors or something else went wrong from last time when the TV "screen begin to dark and It finally did not display at all for hours.."

Do you see an orange glow from the TV's neck close to the neck PCB on the back? You should after a 10-20 seconds of the TV being turned On. Missing heater voltage would be one reason you are not getting an image. Lack of output to the HOT (Horizontal Output Transistor) or the HOT being bad could also be the reason.

So you need to do more parts checking. The small caps on the neck board could also be bad too. If you didn't check them previously, you may want to do so this time around.

[chth96]

Thank you very much for your reply! I also measured all of caps on the small PCB which should be connected to cathode ray tube. By the way, I saw below youtube video. Although I can not understand the language youtube uploader speaks,But it seems that He demonstrate How to check Str 6707 with DMM's diode mode. https://www.youtube.com/watch?v=jl0POb5TeDY So I desoldered Str 6707 from HOT area in PCB and followed the way he demonstrated like below dropbox link. https://www.dropbox.com/scl/fi/b4t7g...=iblh3aea&dl=0 But It seems that my result of measured voltage is totally different from measured voltage in youtube video. Should I trust result of measured voltage in youtube video,and Should I replace this STR S6707?

[momaka]

Both your STR s6707 and the one in the YT video look OK... or at least no hard short-circuit on any of the pins of the ouput transistor (pins 1-3) and no short-circuit on Vcc.
So I don't think that's the issue here.

[chth96]

Both your STR s6707 and the one in the YT video look OK... or at least no hard short-circuit on any of the pins of the ouput transistor (pins 1-3) and no short-circuit on Vcc.
So I don't think that's the issue here.

Thank you very much for reply!
By the way, I found that there is a bad capacitor(samhwa RG 250v 1uf) which doesn't have any ESR ,when I measured it with MESR-100 and its capacitance is less than 250 nf.
this bad capacitor is very close V-DY and H-DY connector.
And another capacitor(smahwa SG 250v 4.7uf) is directly connect to 160V soldering point which is connected to cpt board.
and its ESR value is higher than 10 ohm.
Is it possible to replace smahwa SG 250v 4.7uf with lelon rga 400v 4.7uf and replace samhwa RG 250v 1uf with any capacitor of 105 degree 250v 1uf specification?