How to repair flickering Gateway FPD 1830 flat panel color LCD monitor

One winter morning when I turned on my FPD1830 monitor, the display came on, flickered for about one second, and then turned back off. Thinking it was due to the 40 degree temperature in the room, I left it running, put a towel over it to retain heat, and let it sit for an hour while the room warmed up. Later, pressing either the SOURCE/SET button or the On/Off button forced the display to turn on, but each time, it flickered for about one second and turned back off. Repeating this several dozen times eventually caused the monitor to stay on, so it seemed like a heat (or rather, cold) issue.

On subsequent days, the room was not so cold, but the monitor still would not turn on without this long warmup time and repeated button presses. After the monitor reached its normal operating temperature (which is quite warm), it would operate flawlessly indefinitely, and could even be turned off and back on, as long as it was not allowed to cool down.

Other observations

When the monitor was not working, a strong flashlight shined into or across the display revealed that the LCD image from the computer was there, so the problem was with the backlights not staying on.

If, while the monitor was operating properly, I used the OSD to turn the brightness and contrast down to zero before turning the monitor off, it was much quicker to get into normal operation the next time I powered it up. (If you have to live with this problem for a while, this workaround will reduce the inconvenience.) If I set the brightness and contrast both to 100, it was very difficult to bring up to normal operation the next time, and I had to wait longer between presses of the SOURCE/SET button for it to have any effect.

Background

When I finally got to researching this problem on the web, it turned out that it seems to be common with the FPD1830. It was in this thread at Lockergnome Forums where I found the most useful information about it, including the fix that I employed here, which involves replacing 4 small capacitors on the inverter board.

The participants in that thread didn't mention what, if any, other fixes they had tried first. Having worked as a service technician for two years, I knew that a high percentage of failures are due to bad or failed solder connections (or cabling), so my first thought was that replacing the capacitors might have accidentally fixed some bad connections. I didn't yet have the capacitors, so it was something to try.

After reseating every cable, reheating/resoldering every connection on the power supply board and every non-tiny connection on the inverter board and all the larger connections on the video logic board, I can now report that the problem is not bad connections. It is the capacitors.

Preparation

Here is a procedure for replacing them. If you have no experience repairing electronic equipment, this might be quite a difficult project to start with. Read the forum thread above to get an idea of the problems you might encounter. It also has some tips that should make the project go more smoothly.

Even if you are experienced, it will help to grab a few old junk circuit boards and spend several hours experimenting with desoldering techniques.

This job is additionally difficult because the 4 capacitors to be replaced are small, are nearly flush to the PC board, and are soldered clear through the board holes using, apparently, silver solder which has a high melting point. In short, depending on the value of your time, you might be better off just buying and installing a replacement board.

The forum thread refers to a MoniServ replacement inverter board that costs about $100 and is at http://www.lcdpart.com/Products/6633tza015amss.html. That page also links to a useful but reluctant-to-load PDF file with photos of the disassembly and installation, plus two alternative models of the inverter board, one a refurbished original. In the PDF, their plastic monitor case opens differently from how mine did, and the capacitors on their old board look much different from mine. The replacement board can also sometimes be found on eBay for a low price.

This was a miserable repair job, and I botched it so badly that it is hardly any consolation that the end result works. Everything that could go wrong, did.

Tools

• Soldering iron for electronics work, and rosin core solder
• Solder sucker or bulb and/or desoldering braid
• Regular pliers
• Large needle nose pliers
• Phillips head screwdriver(s)
• Flat edge screwdriver
• Magnifying glass (everything on these boards is tiny)
• Large soft towel
• Egg carton with cups labeled 1-12 for organizing screws and other parts as you remove them. As you remove each part, write down which part is in which cup. Also make diagrams to record the positioning of parts and cables as you disassemble them.
• Four 100 microfarad capacitors rated at 25 Volts or higher. Radio Shack part #272-1028 (35 Volt) will work, as will #272-1044 (50 Volt), which I had to use because that's what they had 4 of. They cost $1.29 each. These two Radio Shack capacitors are the same size, and are slightly larger than the capacitors being replaced. Any capacitors larger than these could pose a problem because of their size. Online stores have similar capacitors cheaper, but have shipping costs, handling fees, and/or minimum orders, so the total cost is more than twice the cost of the parts.
• Shrink-to-fit tubing (or similar insulation) might prove useful, see below.

Opening the cabinet

1. Turn off your entire computer system and unplug the monitor from its power source.
2. Unplug the power cable from the monitor body. Access is easier if you tilt the monitor up as far as it will go, or else lay it gently on its back so the plugs face toward you.
3. Unscrew the retaining screws of the DVI or VGA cable, and unplug it from the monitor body.
4. Lay the towel flat on your flat desk or workbench.
5. Turn the monitor over and place it face down on the towel with its base stand pointing upward. The towel protects the front surface.
6. While firmly holding the monitor base, remove the two screws that attach it to the monitor.
7. On the bottom of the base plate, the side opposite the two screws, the base is held in place by two steel tabs. Tilt the base gently toward you to disengage the tabs, remove the base, and set it aside.
8. The rear plastic case is held in place by 5 screws: at the four corners, and one in the handle. Remove those screws. Note that the screws at the top are different from the ones on the bottom.
9. The two halves (front and back) of the monitor case are merely pressed together, with a seam along the outer edge. Separating them for the first time can be difficult. Be gentle, but persistent. Starting along the bottom edge (where the monitor's controls are located), insert the blade of a small screwdriver into the seam, and press inward gently while twisting the screwdriver to pry the two halves apart. Go all the way around the seam to find where it seems to be separating most easily, and start there. You may have to go around the edge several times before you get them pried apart. Mine made terrific cracking sounds as the halves separated, but there was no damage. Subsequent disassemblies were much easier. Slight dents in the plastic made by the screwdriver head as you twist it may be unavoidable.
10. Lift off the rear case half.

Opening the RFI shield

The internals of the monitor are encased in a steel RFI shield with holes in it. The two halves of this shield are pressed together and held in place with at least 4 small screws. (There are holes for more than 4.)

11. Go around the outside edge of the shield, mark on the shield with a felt pen the location of each screw, and remove the screw.
12. At the bottom of the monitor is a small board containing the circuitry for the monitor's controls. Remove the center screw holding this board in place.
13. Gently slide the board about 1/8 inch to the right to disengage it from the plastic clips holding it in place. Don't remove the aluminum foil tape. The board itself should now be hanging free.
14. Toward the left side of the RFI shield, to the "north" and "south" (top and bottom) of its horizontal center line, are two small (3" long) shiny shields held in place with a screw. Remove the screw of each, and tilt out and remove the shield.
15. Under each shield are 3 small plugs that carry current to the fluorescent bulbs. Draw a diagram to note the colors and orientation of the plugs, and then unplug all 6. Push them inside the case so they will not be snagged during the next step.
16. The two halves of the RFI shield are only pressed together, but it is a very tight fit. Starting at one corner, hold down the bottom half of the shield while you gently raise the top half a little bit. You might have to go around the edges of the shield several times before you get all the edges to separate at once. DO NOT lift the shield more than about an inch at this time. There is still a cable connecting the two halves.
17. Raise the top RFI shield about an inch at the bottom of the monitor (where the controls are) and look inside to see the cable.
18. Move the shield in the direction of the top of the monitor so you can rest the shield's top edge on the table.
19. Holding the shield at an angle with one hand, reach in and unfasten one side of the tape that holds the cable in place, and then unplug the cable carefully from the lower plug (the one lying on the table, not the one in the raised RFI shield, which is almost impossible to disconnect). Get a fingernail under each end of the delicate plug, and gently lever it out.
20. The two RFI shield halves are now separated.
21. Set aside the LCD part of the unit (the half lying on the towel). Nothing needs to be done with it.

Removing the inverter board

There are 3 circuit boards fastened to the inside of the RFI shield. The one on the lefthand side, containing the 6 plugs you disengaged previously, is the inverter board.

22. The one cable going to this board is held in place with a locking plug. Using your fingers or a pair of pliers (better), squeeze the two halves of the plug together while you gently pull up. You should feel the lock (which is at the base of the plug) disengage, and you should be able to pull the plug up with a gentle pull and maybe a slight rocking motion (from end to end, lengthwise). It is a bit sticky.
23. Remove the 5 screws holding the inverter board in place, and remove the board. The 4 capacitors being replaced are lined up in a row near the plug.
24. Note the orientation of the plastic sheets marked "High Voltage" that wrap around the board over its transformers. Carefully pry the sheets off their sticky pads. Remove the sheets and pads and set them aside.

Removing the capacitors

This is the hard part. First, prepare yourself to accept that if you blow this, which is not unlikely, you'll simply have to buy a replacement inverter board and install it when it arrives. It's still cheaper than a new monitor.

I will describe how I did it (and botched it), and how I think you can do better.

How I did it

I applied the soldering iron to the capacitor leg connections, and used the solder sucker to remove as much of the solder as possible. I did not realize that it was high-melting-point silver solder and that it had flowed completely through the hole in the circuit board to the other side, nor that the capacitor legs appeared to be twisted and stuffed into the holes so that they were slightly wedged (?), nor that they had been bent on the solder side of the board so that they would not easily pull cleanly out.

The result was a nightmare. Applying the soldering iron to the solder pads (and wires) on the board would not melt the solder inside the circuit board holes, so I had to resolder all the connections to provide enough surface area for heat transfer. I was then able to wiggle one capacitor mostly out by melting the solder on one leg while pushing the capacitor toward its other leg with a finger of the other hand, then repeating the process on the other leg, so that each leg came out a small amount at a time.

However, I noticed that the capacitor was coming loose due to metal fatigue in its legs, and got the bright idea that I could break off the head of each capacitor, and then pull each of the legs out while heating the solder on the other side of the board. Unfortunately, I did that to all of them before noticing that not one of the legs left behind was long enough to grasp with needle nose pliers, so I was left with little nubs embedded in the circuit board holes, and no way to pull them out. One of them came out by itself, along with the solder, when I reheated the hole with the soldering iron. Another one came out by applying the soldering iron to one side of the board while using the solder sucker against the same hole on the other side. Nice!, but the prolonged heating had made the little neighboring transistors nearly too hot to touch. Too bad. Nothing to do but carry on. There were still 6 legs that would not come out.

I tried pushing one out with a steel probe. No luck, but it made a slight hole, so I put the probe in a drill, thinking that maybe the hole could be enlarged that way. No luck there, so I tried cutting the head off a steel straight pin and put that in the drill. But the pin immediately bent over, bringing the drill crashing down onto the circuit board. No apparent damage.

At this point, I noticed that while heating one of the capacitor leads, the heat from the soldering iron barrel had melted a half moon shape in one of the plastic shields covering the transformers on the circuit board, so I removed both of the shields, which I knew I should have done before, and resumed work.

It became obvious that I was going to have to drill the leads out of the holes. I found a drill bit for PC boards and began drilling. It was going really well! Then the drill bit broke, bringing the drill crashing down onto the circuit board components. Again, no apparent damage to the board, but by this time I was starting to overheat and there was probably smoke coming out my ears. Too bad. Nothing to do but carry on.

The remaining nub of the drill bit was sufficient to drill out all six holes, plus the original two which had still not shed enough of their clinging solder to accept the legs of the new capacitors. And amazingly, the interiors of the drilled-out holes appeared to be shiny and silvery all the way through.

Carefully observing polarity, I inserted the four new capacitors, and discovered, of course, that some of the 8 solder pads had been destroyed.

The 4 capacitors are connected to the board in parallel, so I bent all their legs over each other, positive to positive and negative to negative, and made mechanically secure and incredibly ugly connections among them, and soldered them all together in two big giant blobs, and connected the mess to other points on the board that didn't have destroyed solder pads. If this sounds like desperation, it was, but it was all done under a high powered magnifying glass, so as bad as it was, it was at least not haphazard.

I tested for continuity among the parts that should be continuous, and for discontinuity among the parts that should be discontinuous, and it checked out OK. Covered the bare wires with electrical tape to prevent any shorting against the chassis, installed the board in the monitor, and reassembled it all. By this time, I was numb. I realized that it might immediately sizzle and fry, and didn't care. Oddly, though, I matter-of-factly (and numbly) did expect it to work, and it did, but it brought no joy. This worst-botch-ever was personally devastating to someone who used to be pretty good at this stuff, and I know that the board is an embarrassment that looks worse than Frankenstein's monster.

I did a web search on desoldering technique, and discovered to my surprise that some of the things I'd done had in fact been standard and recommended, as I'd remembered them to be. They simply hadn't worked in this case. That actually was a slight consolation.

How you can do better

Removing the old capacitors

I'm assuming you don't have a desoldering station with a vacuum pump. Who does?

25. First, the stripe on the side of the old capacitors is the negative leg. Record which direction they face. You must install the new capacitors the same way.
26. Do not remove any solder to start with using the solder sucker or braid. Yes, you might damage the solder pads with the heat, but doing it the other way was a disaster, so try this instead. Damage seems less likely. The external blob of solder will serve as a heat reservoir that hopefully will transfer the heat quickly and efficiently down into the hole and melt what's inside there.
27. Use some method to hold the board firmly vertical, lengthwise on the table, with the capacitors toward the top.
28. Grasp a capacitor firmly with large needle nose pliers.
29. While applying the soldering iron to the solder side of the board, use the needle nose pliers to pull gently and steadily on the side of the capacitor with the leg being heated until it releases and pulls out a little.
30. Do the same to the other leg, and keep repeating until the entire capacitor pulls out.
31. If it won't come out, heat more and pull harder (within reason). You might be unbending a leg, which is unfortunately necessary. This is basically your only hope of getting the capacitors out cleanly, so just do it this way and don't do anything that I did.
32. If nearby components get too hot, take a break.
33. Do not under any circumstances allow the head of any capacitor to break off.
34. If you encounter problems, the description of how I did it describes some desperation measures, which is partly, besides catharsis, why that tale was told.
35. After you have removed all 4 capacitors, remove the solder from the solder pads and holes: with the board still held vertically, apply the soldering iron to the solder pad, and press your solder sucker against the same hole on the other side of the board. When the solder is thoroughly liquefied, press the trigger on the solder sucker.

Installing the new capacitors

The stripe on the old capacitors is the negative leg. Be sure to insert the new capacitors the same way.

36. If you have managed to not damage the solder pads, you can insert the capacitors the same way the old ones were, though the fit will be a bit tighter.
37. If the solder pads have been damaged, you may need to attempt some sort of fix similar to the one described earlier where you avoid the use of the damaged pads.
38. However, an easier or cleaner method might be to put insulating tubing on the legs of the new capacitors and install them so they are raised fairly high off the board (not too high), and then solder them in place on the "wrong" side of the board (directly underneath the capacitors). You might have to scrape away some of the green board lacquer to do this. I'm not sure this is possible, but it's something to consider if you get in a tight spot.
39. Then if the new capacitors, sitting high, don't fit well inside the chassis when you reassemble it, you can bend them over. That's the reason for the insulating tubing, so they don't short against anything or against each other.
40. It has been suggested that you cut off the old capacitors, and solder the new capacitor legs to the stumps left behind by the old ones, but as you'll see, the stumps are not nearly long enough to allow this. Besides, the old capacitors are mounted so flush to the board that you can't get cutters underneath them to do the cutting.
    
    However, one person found that it was possible to pull the heads off the old capacitors -- no desoldering! Grab the head with pliers and pull straight up. The legs pull out of the capacitor and remain attached to the board. You can either solder the new capacitors to those legs (but the connection won't be mechanically secure), or desolder the legs and pull them out of the holes, because with this method the legs are long enough to grab with needlenose pliers. 

Reassembly

41. Put the plastic shields back on the inverter board, reinstall it, and reassemble everything, reattaching all the cables as you go.
42. When you get to the fat beige cable that connects the RFI shield to the LCD unit, be sure to tape it back in place in a horizontal position, and placed far enough in the direction of the bottom of the monitor so that it doesn't get pinched between the two halves of the RFI shield as you press them together. You'll see what I mean when you get to this step.

Good luck, and I hope it works. From what I've seen, there have been sufficient reports of success with this fix that it appears to be the definitive solution to this problem with the FPD 1830 monitors, or at least it should be the first one to try.

I found these articles interesting. My monitor was manufactured in March, 2004:

Capacitor failures in PC equipment:
http://en.wikipedia.org/wiki/Capacitor_plague

PCs plagued by bad capacitors:
http://news.com.com/PCs+plagued+by+bad+capacitors/2100-1041_3-5942647.html

Operations manual for the FPD1830 online at Gateway:
http://support.gateway.com/s/Manuals/Desktops/8508866/index.htm

Update Nov. 7, 2007

On October 31 (Halloween, scary!), just a couple of weeks after someone emailed me about this article and I told them I'd had no problems since the repair, the backlights on the FPD1830 went out for good. I turned the monitor and computer on, saw the Windows startup screen, went into the kitchen, and when I came back a minute later, the monitor was a black screen. Turning it on and off made no difference. The backlights absolutely would not come on.

A strong flashlight revealed that the desktop image was there, so the power supply and logic were ok.

On the inverter board, one of the tiny 1mm x 2mm components, next to the line of capacitors, is labeled F1, which usually indicates a fuse. An ohmmeter across it showed infinite resistance. When I applied power to the monitor, one side of F1 read 12 Volts and the other side 0 Volts. It seems likely the inverter limped along for 6 months after my "repair" and finally one of the components I'd overheated failed and blew the fuse.

The fuse is integrated into the board and isn't replaceable. A new inverter costs $100, and would fix the problem unless the blown inverter was actually caused by the failure of something else. If any backlights are bad (they've had several thousand hours of use), they cost $12 each (there are 6). Worst case cost, $172.

So, for $2 less than that, I got a new Acer AL1916WAbd 19" widescreen LCD. It has better specs than the FPD1830, and the 1440x900 pixel display is fantastic. Its only weakness is a somewhat narrow viewing angle vertically.

I still have the FPD1830 and am hoping to try the repair again if I run across someone throwing one away or if I can get an inverter with bad capacitors for just a few dollars. Even though its 6 backlights will eventually be expensive to replace, they give the monitor a display with very even lighting and a wide viewing angle, which are useful features.

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