HP 2009f LCD Monitor no display
Hi all,
A friend asked to check a HP2009f LCD Monitor no display. First thing I do is to plug in the power cable and switch on, but no display, not even blue led light on the power switch. I shine a torch light at the screen but also no dim shadow at all.
The next day during my free time, I opened up the case and check for burn mark,any bulging caps on the power board or driver board or any bad solder joint but i was not able to see any. I desoldered one cap at C864 which is a Suscon 560uf 35V electrolytic caps and it read 565 on a capacitor meter. So I just assume the other caps at C862, C40 & C48 which all looks ok should not be the problem here. I use my capacitor meter to check most of the caps and found all reading is within 10% range as printed on the caps.
After that I reflow new solder on cap C864, plug in a power cable and switch on mains, paying extra attention to check DC voltage on the biggest cap at C854 which is a 120uf 450V main cap. My digital multimeter on DC reads 325V which I think is normal. I also use an analog multimeter to check fuse at south of F850,which shows continuity. Is this meaning the power board has all the necessary voltage ?
Now I suspect the backlight lamp could be ruined, so I connect a 12V SLA battery to a CCFL tester (output 900V) and output to one of the lamp cable and found a dim light glowing on screen. The other three lamp cable also tested the same with dim glow. Is this meaning the back light is still good? So I am bit confused now as to where else should I do further testing to trace which part is the culprit. I am familiar with using a soldering iron and owned a digital multimeter and a digital capacitor meter. Any help and suggestions is very much appreciated. Thanking in advance for anyone kind enough to guide me step by step.
A friend asked to check a HP2009f LCD Monitor no display. First thing I do is to plug in the power cable and switch on, but no display, not even blue led light on the power switch. I shine a torch light at the screen but also no dim shadow at all.
The next day during my free time, I opened up the case and check for burn mark,any bulging caps on the power board or driver board or any bad solder joint but i was not able to see any. I desoldered one cap at C864 which is a Suscon 560uf 35V electrolytic caps and it read 565 on a capacitor meter. So I just assume the other caps at C862, C40 & C48 which all looks ok should not be the problem here. I use my capacitor meter to check most of the caps and found all reading is within 10% range as printed on the caps.
After that I reflow new solder on cap C864, plug in a power cable and switch on mains, paying extra attention to check DC voltage on the biggest cap at C854 which is a 120uf 450V main cap. My digital multimeter on DC reads 325V which I think is normal. I also use an analog multimeter to check fuse at south of F850,which shows continuity. Is this meaning the power board has all the necessary voltage ?
Now I suspect the backlight lamp could be ruined, so I connect a 12V SLA battery to a CCFL tester (output 900V) and output to one of the lamp cable and found a dim light glowing on screen. The other three lamp cable also tested the same with dim glow. Is this meaning the back light is still good? So I am bit confused now as to where else should I do further testing to trace which part is the culprit. I am familiar with using a soldering iron and owned a digital multimeter and a digital capacitor meter. Any help and suggestions is very much appreciated. Thanking in advance for anyone kind enough to guide me step by step.
Attached Files
But today, I’m making an exception here. Why? No idea. Perhaps only because the repair details are still “fresh” in my head… which is ironic, given this is a 16 year old monitor that hardly anyone will care about today. It is new to me, though. 
I picked it up last November from someone on my local Craigslist. It wasn’t very close to where I live, but was close to a family friend that I had to go visit anyways. So after watching the posting on Craigslist for a few weeks and seeing it getting...
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