Question about HP f2105 21" LCD Monitor

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HP f2105 LCD monitor Backlight inverter problem

After a minute or so the inverter shut's down, so no light, and no picture.
Turn off and on the monitor brings the inverter back to work for a minute or so.
I turned the small potentiometer on the inverterboard, there seems to be a little influence on the time.
Seems that there is a component overloading protection misadjusted or so.
Does anyone have a schematic on this board, or an idea how to save 90 bugs to buy a new inverter?

Many thanks.

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  • Anonymous Dec 02, 2008

    Monitor turns on for 2 seconds then screen goes back but power button is still blue.

  • repapyob Jan 06, 2009

    Same monitor, same problem. I also had to replace the video card in my
    HP desktop, but that did not solve the monitor problem. HP tech support
    abandoned me as I was just two months out of warranty. What I have
    discovered through a lot of time surfing complaint sites is twofold. #1
    The power inverters on the f2105 fail frequently, about the same time
    13-15 months out, and #2 HP will doing nothing to help. It seems to me
    HP should be issuing a recall as they must know there
    is a problem. The issue for me has been finding a reliable replacement inverter. After trying Moniserv and having it fail just out of their 90 day warranty, I am
    still searching. Let me know if you find a good one please.

  • pzheng Jan 31, 2009

    I have the same modle of F2105 and had exactly the same problem. I paid $40 for a dignose at the Staples in Halifax, Nova Scotia, Canada, and was told a problem of its inverter. The cost of a repairing is over $280 and was suggested to replace the unit. I called the HP support centre and was told out of warrenty and got no assistance. Anyone had a solution yet?



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SOURCE: Monitor's backlight inverter shuts down.

what is the exact model maker of the tv...? and also if you can provide the part # that would be great.!

Posted on Oct 31, 2008

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Hp f2105 21 LCD Monitor

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Monitor's backlight inverter shuts down.

what is the exact model maker of the tv...? and also if you can provide the part # that would be great.!

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MY HP f2105 21" LCD Monitor is blank, when I reboot, at the startup, I saw only one or two second of HP opening screen and monitor goes back like if there no connection. In I shut off the monitor and...

You may be having either the power supply failing due to bad caps, or failed backlight inverter circuits due to short circuits, loose connection due to bad solder joints, or failed lamp assmblies. You will have to open it up and inspect the inside. Do you have proper tolls for electronics repair, isolation transformer for safety so you do not get killed by high voltages inside the monitor?
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The montier turns on then turns right off

When a monitor display image for a second and then goes to black screen... there are possible reasons why this problem occur..

1. You need to check if the high voltage ballast transformer of your backlight inverter is about to be burned... the transformer is overheating..that's why you experience the monitor working for a couple of seconds and then it will shut off until the transformer cool down again and then it will be ready to work again...

2. Check also the backlight inverter if it is busted...the backlight inverter is the light source responsible for the image display you seen on your screen. If this are busted then all that you will be seeing is black screen

3. You need to check the power supply section for possible loose connections and possible blown and bad capacitors..

the ballast transformer has direct effect on power supply section.. when there is overheating transformer,,, the supply current from the power supply section becomes unstable.. and will not be able to supply the remaining good working ballast transformer.

In case you do not know, the ballast transformer generates high voltage for the backlight inverter to work....

Please be advise that if you don't have the knowledge, the proper skills and the right tools to open the back cover of your monitor and replace its part...don't risk it...

Otherwise, bring your unit to a credible technician and avail of warranty if there is any.....

Much appreciated if you rate this help...thanks...

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Does it do the same when you use this monitor with other PC, new VGA cable, just need to narrow down the problem first before start taking the monitor apart.
See pictures of what usually goes bad (mostly failed capacitors) with monitors:
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My screens works for about 10 or 15 minutes and then goes out...

You could have a faulty inverter or a CCFL lamp, To determine if you have a LCD screen, inverter or video card problem, read this and follow these instructions.
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Hp f2105 monitor works for about 1 minute and then blank screen. turning the monitor off and on again brings back the screen


It sounds like you have a monitor with a common problem. After a few years some LCD monitors will blow a power supply. The problem is caused by parts called capacitors overheating in the confined space of he monitor. If you are good at electronics repair/soldering you can usually fix he problem. Check out a few pictures on my web site You can take the back cover off your monitor and look for the bad parts,replace any that look like the pictures and your monitor should work fine. The capacitors do need to be installed with the correct + and -connections, note the stripe on the old one and insert the new one the same way. If you don't want to try the repair yourself we offer a repair service for $45 plus shipping. If your problem is not the capacitors then it would be the backlights and that is much more difficult to replace.

I hope this helps, if so please rate my solution.

Corporate Computer
Over 21 years of computer and printer support/repair

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