HP F1703 LCD monitor not working
I too had my monitor go black today (Jan 17,2006). The blue light power switch stays on(monitor getting signal,orange would indicate sleep mode), but the screen goes black after just a few seconds.
Pushing the power button off then back on would give me a display for 2-4 seconds then go black again.
Taking a strong flashlight to the screen would show that the LCD display itself was working. So it became a backlight issue, and i Googled for that.
Visiting the HP site, shows that my monitor is not covered by the extended warranty for the F1703 monitor(my manufacturer date was July 2003). The reason this problem didn't surface earlier was because my computer was in storage for 1 year.
I suspected a power supply problem from the onset since the problem became increasing worse over the last 3 days, until finally it would only stay on for 2-4 seconds at a time.
Visiting the Cnet forum indicated a manufacturing defect. The following web page shows detailed pictures of my exact problem, which is called a cold solder joint.
If a solder joint isn't soldered properly to begin with, over time the solder crystalizes due to heating and cooling cycles of the joint. In this case, maybe the enamel coating wasn't removed from the coil sufficiently, causing improper solder wicking. In time, resistance begins to builds up, causing even more heat to be present at the joint, causing further increased crystalization and electrical resistance(a snowballing, avalanche effect).
Repair takes about half an hour. The tricky part is separating the back half of the monitor from the front silver bezel.
The following disassembly instructions were taken from another post with additional comments added and/or modified as the post left no resolution.
Tools needed: a #2 philips screwdriver, 1/8" round shaft jeweler type small flat head screwdriver and a 1-1/2" spackling putty knive(all from Home Depot). 15w soldering iron, solder sucker, 60/40, 20 gauge(.031 dia) solder(all from Radio Shack). Never use a high wattage soldering iron or heavier gauge solder on a printed circuit board, or you will be buying a new monitor!
1. Remove all electrical connections from your TFT.
2. Using the 1/8" flat head screwdriver, remove the two blue plugs just above the silver stand bracket on the rear of the screen, by sliding the sharp screwdriver down along the outside edge of the plug and prying upward. Remove the two brass screws
3. The screen and the stand should now be seperated.
4. Using the putty knife gently pry the silver bezel away from the blue body of the monitor from the outer edge - Best place to start is at the bottom corner of the screen near the menu - + select buttons. You may hear slight cracking - crack is good, snap is bad. Work with the putty knife from the back side of the monitor, being extremely careful and gentle. Work in a well lighted room with a non slip-pad on the table to protect the screen. Best results are obtained by holding the monitor on edge, sliding the knife in between the bezel and case and prying downward toward the center of the monitor. Work in one direction from the menu button corner and along the bottom, then up the side, accross the top, and back down the side. Separating the bezel was not easy but once a technique was established, it became easier.
5. When the silver facia is removed, you will see about 12 screws on the front of the screen (these hold the screen to the body) - remove these screws.
6. Carefully turn the screen face down. You will see an aluminum looking heat shield. Using the knife cut threw the 2 metal tape seals.
6a. Remove the two locking spacer nuts on the blue 15 pin D connector.
6b. Remove the two screws on each side of the heat shield.
6c Gently push the heat shield towards the bottom of the screen to free it from the tabs.
Remove the 4 screws from the FL backlight inverter. There are 4 toriod coils on this circuit board.
Refer to the link for detailed pictures.
The solder joint discoloration(yellow-brown) on the solder side of the FL inverter board, indicates too much heat was present and a possible cold joint (I had only 1 bad joint, at the exact same location as pictured).
Good soldering techniques should be practiced before making the repair. A bad, cold solder joint does not look shiney. If you don't know how to solder practice on some 18 gauge scrap wire first. Placing the soldering iron against the joint for about 7 seconds seconds and applying a minute amount solder until it flows, is all that is necessary for the proper repair. Don't apply too much solder, if you do suck it back off with the solder sucker tool, and reapply a "minute" amount. Compare your joint with others on the board.
7. Now reassemble the monitor using steps 5, 4, 3, 2 and 1. Snapping it back together again is a breeze.
So for the $25 worth of tools you can be up and running again in no time with your own monitor, and not some old reconditioned monitor HP replaces for you for free or not.
F1703 not working HP Hewlett Packard 17" LCD monitor TFT display goes black shuts off no backlight
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