CTX CVP-5468NI picture increased width then shrank

[luRaichu]

Originally Posted by luRaichu

There's a cap (C427) which lives right next to the LA7850 and H-hold adjustment and it looks like the type that cracks and smokes. I totally forgot what it's called

This. It looks like a mini RIFA to me...

[vol.2]

Originally Posted by luRaichu

This. It looks like a mini RIFA to me...

Pull it and check the ESR. Did you pull C322 and check it?

[luRaichu]

I have to buy a component tester.

[vol.2]

Originally Posted by luRaichu

I have to buy a component tester.

I would recommend it. You can either buy one of those cheapo testers they have on ebay or if you want something a little more trusted, the Peak ESR meters have a decent reputation.

Personally, I have one of those cheap ones, but I also have a real LCR meter. Between the two of those things (and my DMM) I'm able to test most anything I need to.

Honestly, I've seen you around here enough that at this point you probably want to have some tools to make your life a little easier. You have to consider how much your time is worth, stabbing around in the dark and replacing component hoping it will help.

[luRaichu]

I pulled C322 and C427 today but the cheap LCR-T4 I bought only measures their capacitance, not ESR.
C322 rang up as 50pF on both the LCR and my multimeter!
It should be 220nF. The code on the package is 224J which means 22 x 10^4 = 220000pF with 5% tolerance. The second line says MP400 which I assume means rated 400V DC.
https://files.catbox.moe/7prbnh.jpeg
I’ll find a replacement mylar cap on DigiKey but let me know if there are any special considerations to be made.

Here is C427. Measured capacitance was close enough to 330pF.
https://files.catbox.moe/w1rpj1.jpeg
Should I replace it? I still don’t know its ESR.

[vol.2]

Originally Posted by luRaichu

I pulled C322 and C427 today but the cheap LCR-T4 I bought only measures their capacitance, not ESR.

Are you sure? I have a similar cheapo tester that has ESR on the screen when I test for capacitance.

C322 rang up as 50pF on both the LCR and my multimeter!
It should be 220nF.

yep it's bad.

Here is C427. Measured capacitance was close enough to 330pF.

I can't see your picture. It's a bad link for me.

I believe that 330J is a 33pF code (33 for the digits and "0" for the number of places). What does it measure?

Also, the cheapo testers sometimes don't go down very low, and they definitely can't go up very high. So it might be outside of it's limits.

[luRaichu]

Originally Posted by vol.2

Are you sure? I have a similar cheapo tester that has ESR on the screen when I test for capacitance.

I put a 2200uF electrolytic cap in my tester and it measured the ESR of that. I don't think the ESR test works for caps in the pF range.

Originally Posted by vol.2

I can't see your picture. It's a bad link for me.

Works fine here... It's just a picture of a film cap that says 330J and S50F.

Originally Posted by vol.2

I believe that 330J is a 33pF code (33 for the digits and "0" for the number of places). What does it measure?

317pF. Again, the formula is [first two digits] multiplied by 10 to the power of [third digit]. 10 to the power of 0 is just 10 so 33 x 10 = 330 (which is the full three digits anyways). If it was 33pF, why wouldn't they just save ink and write only "33"?

[vol.2]

Originally Posted by luRaichu

317pF. Again, the formula is [first two digits] multiplied by 10 to the power of [third digit]. 10 to the power of 0 is just 10 so 33 x 10 = 330 (which is the full three digits anyways). If it was 33pF, why wouldn't they just save ink and write only "33"?

Okay, nevermind. I got myself confused about it because we were talking about pF. 330J is 33nF, which is the same thing as 330pF.

[luRaichu]

Here’s the C322 replacement I picked.
https://www.digikey.com/short/5c3crh37
Hopefully it’s appropriate.

[vol.2]

Originally Posted by luRaichu

Hopefully it’s appropriate.

Looks good to me. Low loss, 450V. Should be better than what came out of there.

[luRaichu]

After replacing C322 the XGA mode works again. Here's a picture.
The brand new 220nF cap measured 30Ω ESR on the cheap LCR

[vol.2]

Originally Posted by luRaichu

After replacing C322 the XGA mode works again.

Awesome! Glad to hear you got it rolling.

The brand new 220nF cap measured 30Ω ESR on the cheap LCR

That is definitely not right. Film caps are generally very low ESR. I suppose there could be something about the way the cheap tester does the ESR measurement that isn't good for filim caps, or it's possible that it has a narrower range for ESR.

Also possible that it's just not super reliable. I generally use my cheap tester as go/no-go tester and I don't rely on it for precision.

If you decide to get something that is specifically more reliable for ESR, people seem to like the PEAK devices.

I decided to get a DE-5000 LCR meter after watching a bunch of reviews, and I'm happy with it. It is not quite as convenient to use as the PEAK meter, but it's got a wider range of functions and seems to be pretty accurate according to the hobbyist community.

[Alex KL-1]

Perhaps a not so good ESR meter can measure with low frequency so low value caps, not being electros of high µF, will end measuring reactance and not ESR.