Re: HP LP3065 monitor half bad screen
That was an intresting video. Thanks for the link. I hadn't gotten around to taking of that part of the trim to expose the flex connectors to the screen, so I did that. There are 12 flex cables each with a chip attached to the back side. There is a pressure plate on the frame that goes over the top of them to put pressure on them, or act as a heat sink (not sure which). I pushed and prodded all of them with no effect on screen performance. Cold spray didn't matter either but the chips attached to the flex do get pretty hot. Hotter than seemed...
mjsbv
Member
Last Activity: 01-12-2014, 07:30 PM
Joined: 02-25-2008
Location: Lebanon Oregon USA
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Re: HP LP3065 monitor half bad screen
Update. I've managed to recover the quarter of the screen that died, but the bottom quarter is still elusive. The problem seems to be the horizontal scan data isn't making it to the screen. When I mess with the two flex connectors that go from the interface board to the screen I get varied results. The quarter that came back (and has stayed so far) did so after I cleaned/polished the ends of the flex. I got the bottom quarter to come up briefly one day when it was particurarly cold in the shop. If worked for a few min but faded out as the screen...Leave a comment:
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Re: HP LP3065 monitor half bad screen
Here is a pict's of the screen.
Thanks in advance for your help.
mjsbv...Leave a comment:
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HP LP3065 monitor half bad screen
I've just aquired an HP LP3065 monitor, with a partial functioning screen. I've read through previous posts about this monitor but none seem to describe the problem this one has. When I got it the bottom quarter of the screen showed perfectly straight vertical lines in a random array of colors. The top 3/4 was fine (this was the reason it was discarded). After a short time turned on the next quarter up has joined the bottom quarter and now also shows the same banding (in perfect alignment) so its half good half bad now. No flickering or dancing around, but the bands are different from one time... -
Re: Help with a HP L1800
I replaced the two caps on the inverter board.Leave a comment:
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Re: Help with a HP L1800
My monitor looks pretty different than yours. It also only has a simple 12v power brick with coaxiel plug. The four caps that were labled were samaxon or something like that. The inverter board says samsung on it. The main board has no name at all which is unusual for an HP designed board (if it is).
I used the o-scope to check out the sm al caps on the main board under power and found 2 with a little ripple. When I replaced these the wavy lines went away, yea, but when started cold the next day were back and worse than before. The caps I...Leave a comment:
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Re: Help with a HP L1800
I spent a bit more time working on this thing and have found it seems to have two problems. One is the wigglely lines that angle across the screen at about 30 deg from horizontal and slowly scroll vertically and the other is one half of the inverter isn't working. It only lights one lamp and the same side works on the other lamp when I switch the lamps. Intrestingly the side that works is the one that had the goo all over it. There are several surface mount power transistors that I'll test. I think that explains the dim screen but not the lines.
...Leave a comment:
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Re: Shorted HP L1955
Unfortunatly I didn't take a picture with the microscope to show the cracked solder joints and I fixed them before I thought of it. I used a stereo microscope with about a 12x zoom lense to look at it. That scope has a CCD camera that also looks through it and outputs the scene to a video monitor and a video image capture printer. A nice tool I have access to at work. I have found however that a high megapixel camera with good macro capibility can be pretty good poor mans microscope when the image is enlarged onscreen. The pictures in the earlier post were taken...Leave a comment:
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Re: Shorted HP L1955
The original fuse was a 5 Amp. The 4 A in the picture in post 3 was a temporary one I put in. I didn't want to blow the one 5A replacement I had while troubleshooting the board.Leave a comment:
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Help with a HP L1800
I've got a L1800 monitor by HP (D5065A) with some issues. It still works but lamps seem dim and has significant wavy horizontal lines moving verticly on screen. This is an older unit built in 99 and built like a tank. No cost reduction efforts in this baby. It has a backlight timer that says it has 27000 hours on it with 3000 left so I'd guess the lamps are about done for. But if it didn't have the lines would still be useable. I cracked it open and found no bulging or leaked caps just one little 4.7 uf with a red dot on top (don't know if thats a leak or not so I replaced it). Only other thing... -
Re: Shorted HP L1955
A quick update to the L1955 repair. I ordered a collection of Panasonic FM caps from digikey along with replacement 5A fuse and Fairchild [URL=http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=FDS9435ACT-ND]NDS9435ACT[/URL] Mosfet to replace the 4431 (I didn't want to place another order from Newark just for that and they did'n't have small order quantities of Panasonic caps available). I think this is an equilivilant replacement, let me know if you don't think so. I got some 5707's from ebay. Replaced all the caps, fuse, one mosfet and 2 transisitors...Last edited by mjsbv; 03-10-2008, 10:10 PM.Leave a comment:
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Re: Shorted HP L1955
Ok I'll fess up. The two caps in the secondary are not originals. The board was virgin before I started messing with it and was loaded with elite and lelon caps. I dug a couple Mallory CE's out of the bin at work that were the closest I could find to replace the two that had black smudges on the top. They are the correct uf value but are 63 volt and only 85 deg. temp rating. I figured I'd put them in temporarly to see if the board would work. It didn't, so I started looking elsewhere. I'll pull them out and replace with probably panasonic but I'll have to order...Leave a comment:
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Re: Shorted HP L1955
Thanks Krankshaft...I didn't find that thread and your board is identical to mine. One of the FET's seems good the other is shorted. I'll get enough to replace them several times if I don't get it right the first time. Did you replace all the 5707's also?
Here are some picts of my board...Leave a comment:
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Shorted HP L1955
Hi all, I'm new on the fourm and am working to bring a HP L1955 LCD monitor back to life. Its probably identical on the outside as the HOODLAM describes but the power inverter board is a little different. The board is a benq 48.L1A02.A00.
Inital symptoms are power light comes on flashes yellow then turns green and stays solid green but no display either with out without video input. With alot of squinting I can make out the menu display when the menu button is pressed so it looks like the video logic must still work. I tried a flashlight but still couldn't make out any more than...
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