Usage of ultra low esr capacitors on lcd power boards

[jpyerry]

I recently repaired a Samsung 930B monitor power supply board by replacing the capacitors.

For a couple of the capacitors I used Panasonic FR series capacitors which I understand fall in the category of being ultra low ESR.

The monitor turns on and functions, but I've gotten worried because after doing some reading on the forum, it is not a good idea to use ultra low ESR capacitors on power supplies.

So, for long term stability (I really like this monitor), would it be advantageous to pull the FR capacitors out and put in some capacitors like from the Panasonic FC series? Or should I just leave it alone?

Thanks,
Justin

[budm]

Re: Usage of ultra low esr capacitors on lcd power boards

The thing you have to worry about using too low ESR is the stability of the power supply and how was it is designed to tolerate wide ESR range, some may become unstable and oscillate. To find that out you will need the scope to look at out put and see waht kind of high frequency signals you are seeing at the outputs. I would not worry about it. The power supply designed for the monitor are very basic not like for precision voltages needs in mother board.
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"Application examples

Switching mode Power Supply:
Switching mode Adapter
line noise removal
LCD backlight
LED applications
Applications with long lifetime requirements"

[jetadm123]

Re: Usage of ultra low esr capacitors on lcd power boards

I would not worry about using the FR series as they are being advertised as having a much longer life span than the Panasonic FM/FC series. If you look at the spec sheets for the FR/FM series, you'll see the specs for ripple current and impedance very similar. In some cases the ESR for the FR series is actually higher than the FM series. The FR/FM/FC series are recommended by a lot of members (myself included) for monitor/TV repair. You're fine leaving the FR's on the board.