Forcing direct supply to PC display LEDs,but current remains=0

Hi,

A friend has a fancy All in One PC,HP610 Black screen..always..boot included No VGA or HDMI out. Turning it on ,it sounds ok from loudspeakers during loading,the typical Windows start sound is clear.

In a repair shop after 30 minutes the diagnosis is "motherboard to change"...not less than 350 euros,a big cost.

I said to him wait and bring it to me,because by me

1)I don't think they even opened it 2)The GPU,that is likely to be fault is on a 80 euros removable board,not

a BGA on motherboard

3)At least the LED backlight inverter deserves a check

Once opened i check the inverter,looks like a step up..one inductor,one diode,capacitor on out (Cout=2 x 10 uF 100V).Vin=19 V..but Vout=0V Ok,supposing the inverter is KO,i want anyway to turn on the LEDs,to check if some image is present on the display. So i disconnect inverter input,and i apply voltage to Cout from 0 to

90V,with 10 mA current limit,but Iled=0. Is there a opened LED?Maybe.Is the capacitor connected to output connector os some burned tracks? Positive is connected,but negative don't.The negative terminal of Cout goes to PCB GND,but GND is not connected to output connector.The only path is across the metal columns supporting the board. A bit odd.

What is your opinion?Thanks.

Diego

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Reply to
blisca
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Get a second, even a third opinion. It probably really needs an OS reload or restore. Did you try safe mode ? If it can do that 80% the mobo is good.

And BTW, since after Win98SE you have to do the OS all over again with a new board. I know how to migrate 98SE to another PC but it is impossible with XP or later.

Reply to
Jeff Urban

Another reason I am using MAC OS still. Most of my time is spent using the computer, not figuring out what went wrong...

I expect Linux is also like that, as any system based on Unix seems pretty robust.

John :-#)#

Reply to
John Robertson

My son started working for MS and he told me that on their servers they use a Linux based system.

Bad thing when MS will not use their own softwear for the 'cloud'.

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Reply to
Ralph Mowery

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