samsung b4k-50 capacitor issues?

[flyguyeddy]

ok heres what i have. samsung b4k-50 rev 01 assy lj44-00051a.


my tv is an ilo 42" plasma with this power board in it. it was working fine yesterday and i moved some stuff around which included unplugging the tv and moving it about. plugged it in and nothing. took it apart to find the 330uf caps are bubbled out on the tops.

is this a common mode of failure for this board? are these caps easy to come by?

heres what they look like. usually on everything else ive dealt with a cap that looks like this is most certainly blown.

[PlainBill]

Re: samsung b4k-50 capacitor issues?

Don't post pictures inline. They seriously inconvenience retiredcaps and irritate many others.

The capacitor isn't bulged; that's a plastic disk on top that is bulging.

PlainBill

[flyguyeddy]

Re: samsung b4k-50 capacitor issues?

Is that not a sign of a failed capacitor?

[PlainBill]

Re: samsung b4k-50 capacitor issues?

Is that not a sign of a failed capacitor?

Nyeah.... All of the electrolytic capacitors in a TV or monitor are made by the same general process. An aluminum can is formed, the electrolyte and plates are inserted into the can, and the open end sealed with a bung. Then a sleeve with brand, series, and capacitance is heat shrunk around the can. There are some variations - the can for caps of roughly 220 uF and above a pattern stamped into the closed end so they will vent in a controlled manner (this actually depends on the diameter of the can). Smaller caps don't have that pattern. Very large diameter caps, especially those which operate at high voltage, have a plastic disk on top, held in place by the heat shrink tubing. That disk frequently bulges. If you can press it down, the cap is good, if the metal cap of the can is bulged, the cap is bad.

By the voltage and capacitance rating, the cap in the picture is part of the rectified mains filter. It operates at 120 Hz, and is under much less stress than the output caps which are fed pulses in the range of 40Khz-70Khz. (Some recent power supplies have a SMPS operating in the Mhz range.)

Now, it's a free country,, and you can replace the caps if you wish. But unless there are other signs of a problem with that cap, you won't see any change in behavior.

PlainBill

[flyguyeddy]

Re: samsung b4k-50 capacitor issues?

ah gotcha. well the reason i thought they might be an issue is because i have a toshiba computer monitor that popped a few caps and they all popped through the top of the can.

anyway, i dont know where to start with this tv. i plug it in and turn on the switch on the side. i can here a few faint clicks and the light on the front blinks a purpleish color and the set refuses to turn on. the light blinking has never happened before.

ilo model p42bsmt-u32. says it was mfg'd in 2004.

i also cannot seem to find an owners manual or anything for this tv on the net. i have been able to find NO burned or obviously failed components on any of the boards.

[PlainBill]

Re: samsung b4k-50 capacitor issues?

No luck finding a service manual either.

PlainBill