HP LP2465 constant screen flicker

[TheCaller]

Hi Folks.

I am new to the forum so please excuse me for any mistakes or repetitive questions.

After much thought i have decided to try and repair the screen flicker on my HP LP2465 monitor instead of sending it for probably a costly repair. The screen constantly flickers but i get intermittent flashes of a clear picture.

I have managed to remove the back casing of the monitor revealing the boards. From what i have read, the symptom points to damaged capacitors? However, i am not able to see any damaged capacitors at all. None of the Capacitors are showing any signs of damage.


The left board has 3 CapXon 220uF 35v Capacitors.

The power board has 5 Elite 470uF 35v Capacitors, 1 black TB 1uF 100v Capacitor and 2 brown KY 47uF 50v Capacitors and 1 large brown Capacitor.

The right board has 9 black TB 220uF 25v Capacitors, 10 TB 47uF 25v Capacitors, 4 TB 100uF 25v, 8 KY 22uF 50v Capacitors.

I have taken a number of pictures which are attached.

Does anyone have any ideas what the cause of the screen flicker may be or what remedial actions i can perform? Bear in my mind, my electronics knowledge is very limited.

Any help would be greatly appreciated.

Many thanks.

[tautech]

Hi Folks.

I am new to the forum so please excuse me for any mistakes or repetitive questions.

After much thought i have decided to try and repair the screen flicker on my HP LP2465 monitor instead of sending it for probably a costly repair. The screen constantly flickers but i get intermittent flashes of a clear picture.

I have managed to remove the back casing of the monitor revealing the boards. From what i have read, the symptom points to damaged capacitors? However, i am not able to see any damaged capacitors at all. None of the Capacitors are showing any signs of damage.


The left board has 3 CapXon 220uF 35v Capacitors.

The power board has 5 Elite 470uF 35v Capacitors, 1 black TB 1uF 100v Capacitor and 2 brown KY 47uF 50v Capacitors and 1 large brown Capacitor.

The right board has 9 black TB 220uF 25v Capacitors, 10 TB 47uF 25v Capacitors, 4 TB 100uF 25v, 8 KY 22uF 50v Capacitors.

I have taken a number of pictures which are attached.

Does anyone have any ideas what the cause of the screen flicker may be or what remedial actions i can perform? Bear in my mind, my electronics knowledge is very limited.

Any help would be greatly appreciated.

Many thanks.

Welcome to the Forum.
Caps often show NO signs of degradation.
The CapXon brand have a universal reputation of poor quality.
Most often the smoothing caps of the SMPS output decrease in value to low uF values.
They are subjected to substantial ripple levels and often fail.
I have seen 1000 uF caps measure only 100 uF.
This causes considerable ripple in the DC power rails and all manner of apparent circuit faults.
If you have a Cap test mode on your DMM, it should show you this.
Any E Cap that measures ~10% below its label value should be replaced.
However for SMPS, the ESR value of a cap is important too.
This can only be tested with a meter that shows the ESR value.

Some people go for a overall replacement of the caps, I will measure a few outside the SMPS, but normally only replace SMPS caps with same value Low ESR types.

[marshallh]

Replace them all.
Get on digikey and find replacements using parametric search within the Panasonic FC/FM series.
You can test them individually, but if you have to desolder them anyhow, just put a new one in.

[EMUD]

Hi,
often this is a problem with the xformers of the backlight cfl. I have seen a lot of them in your screen. You may check secondary and primary with a ohm meter and compare them, a difference more then 10% is bad. There is normally no need to desolder them check them.

Good luck!

EMUD