How bad does a bad cap look?

[catleugh]

My tv stopped working this week, blank screen & no sound, but power OK. Took the back off and had a look at the main board. It looked OK at first, but when I had a closer look at the capacitors, saw that 5 of them had very slightly bulging tops. Think that may be the problem? I've sent for some replacements anyway, because if it's anything else it will be cheaper to buy a secondhand TV, rather than get this one repaired.

[stj]

Re: How bad does a bad cap look?

caps go bad BEFORE they look bad.
so if they look bad - they are very bad!

[goontron]

Re: How bad does a bad cap look?

caps go bad before they look bad.
So if they look bad - they are very bad!

This! +1

This site has a resource on that: https://www.badcaps.net/index.php?pageid=identity

[catleugh]

Re: How bad does a bad cap look?

Thanks guys.

[cdrsteve]

Re: How bad does a bad cap look?

I too feel your pain. After literally years of procrastination, I finally got serious about opening up my Sammy 61A750 DLP to do some long overdue cleaning and repair its increasingly noticeable "white dot" problem. This TV has VERY HIGH usage so in the back of my mind I "knew" there would be other (cap) issues once I got inside. Not only did I find numerous bulging PS caps (and I mean BULGING), I found one totally open (560 uf/200wv) and many more with bad ESR and/or capacitance levels. Needless-to-say, they are all now sitting on my bench with their legs in the air while I research replacements. Thank you "SAMWA" for years of service but you will be replaced with Pannys!!! Good luck on your set - don't give up..... repairs can be "fun"!

[Mint Waxed]

Re: How bad does a bad cap look?

My tv stopped working this week, blank screen & no sound, but power OK. Took the back off and had a look at the main board. It looked OK at first, but when I had a closer look at the capacitors, saw that 5 of them had very slightly bulging tops. Think that may be the problem? I've sent for some replacements anyway, because if it's anything else it will be cheaper to buy a secondhand TV, rather than get this one repaired.

For your viewing pleasure, here are some really bad looking caps.
https://www.google.com/search?q=capa...w=1030&bih=887

[bianchi77]

Re: How bad does a bad cap look?

caps go bad BEFORE they look bad

How can we know the caps are bad if they don't look bad ?

[junktv]

Re: How bad does a bad cap look?

These are still working.

[stj]

Re: How bad does a bad cap look?

How can we know the caps are bad if they don't look bad ?

with an ESR meter

[joshnz]

Re: How bad does a bad cap look?

How can we know the caps are bad if they don't look bad ?

ESR meter.
i have had many caps that look like new that are bad

[Mint Waxed]

Re: How bad does a bad cap look?

How can we know the caps are bad if they don't look bad ?

Place a stethoscope on the top and listen for a gurgling sound.

[kc8adu]

Re: How bad does a bad cap look?

no they are not.those are open now.
the 2 polys are eating all the ripple and allowing the board to limp along.

These are still working.

[stj]

Re: How bad does a bad cap look?

How can we know the caps are bad if they don't look bad ?

you may want to get something like this.
http://www.ebay.com/itm/222210243721

[mikail13]

Re: How bad does a bad cap look?

ESR meter.
i have had many caps that look like new that are bad

+1
https://www.badcaps.net/forum/showthread.php?t=56932

no bulging. looks like new..All of bad 400 v.

[cdrsteve]

Re: How bad does a bad cap look?

These are still working.

Wow, that board looks a bit rough! Used to see a lot of pcb's and components looking like that when I was repairing in Hawaii. That salt air gets to everything after a while.

[junktv]

Re: How bad does a bad cap look?

no they are not.those are open now.
the 2 polys are eating all the ripple and allowing the board to limp along.

Speaking of ripple sometimes the bestech psu powering it needs a little heat from a hair dryer to get going.

It needs some attention but so long as it doesn't catch on fire i'm not to concerned with it.


Wait actually i better get at it. I was going to move it to the garage.

[cdrsteve]

Re: How bad does a bad cap look?

I too feel your pain. After literally years of procrastination, I finally got serious about opening up my Sammy 61A750 DLP to do some long overdue cleaning and repair its increasingly noticeable "white dot" problem. This TV has VERY HIGH usage so in the back of my mind I "knew" there would be other (cap) issues once I got inside. Not only did I find numerous bulging PS caps (and I mean BULGING), I found one totally open (560 uf/200wv) and many more with bad ESR and/or capacitance levels. Needless-to-say, they are all now sitting on my bench with their legs in the air while I research replacements. Thank you "SAMWA" for years of service but you will be replaced with Pannys!!! Good luck on your set - don't give up..... repairs can be "fun"!

Amazing just how much of a difference this old set looks with a full re-cap and DMD chip replacement! Bad (and sometimes, marginal ones) caps DO make a difference!

[Mint Waxed]

Re: How bad does a bad cap look?

You can say that again! I finally got around to updating 17 caps in a Gateway FPD2185W monitor and brought it back to life. Actually, I have six of them bought on the cheap from eBay. Manufactured around 2005, they were part of the great Capacitor Plague and people not knowing a capacitor from a resistor were dumping them in droves. Originally, these monitors were msrp at around $600. The LCD has Samsung stamped on it as well as the chassis but the power & video boards were made in China. Four of them are completely restored while one still has a vertical yellow line on the LCD. Another has a cluster of pixels stuck on gray. Both with defects however are still usable. You might say my hobby is keeping old junk alive.