My latest project is a Dell 2208WFPt, a 22" widescreen computer monitor with LCD backlighting. The problem is it doesn't always display the image on screen. Sometimes you turn it on and you can see the image, but most of the time with you turn it on there is no image on screen. The flashlight test confirms the problem is the backlights aren't always coming on. Before I even open up the monitor I suspect bad capacitors.
This monitor is noticeably newer than previous monitors I've worked on. Most monitors I've worked on are from about 2005, but this monitor dates to 2008, which means it failed in the 2 - 3 year time span.
Disassembling the monitor is a bit of a challenge. You start by pressing the button on the back of the screen which releases the stand. After you remove the stand there are four screen in the back of the monitor (behind where the stand was). Next flip the monitor over so the screen is facing up. Now the tricky part. You need to pull/pry the black bezel up away from the screen. To do this I used one hand to pull up on the screen from the inside of the bezel (I got my fingernails between the bezel and the glass of the screen). At the same time I used a screwdriver in the other hand to pry at the bezel from the outside. The trick is to pry the silver frame away from the black bezel. You need to start on the side of the monitor furthest from the controls. Next work the top, then the other side. Finally you can work the bottom, but be careful the of the circuit board for the controls. The wire is soldered to the circuit board and there's very little slack. Once the bezel is free you can remove three tiny screws holding the circuit board to the bezel. This multi-part video shows the disassembly I've described thus far.
Next you can lift out the screen. To remove the circuit board cage you need to remove all the wire connections, and there are 4 screws holding the cage to the side of the panel itself. Be careful with lifting up the screen, you must slowly lift it up and reach underneath to disconnect the LVDS ribbon cable.
Finally you can remove the circuit boards. You need to remove both the video and power boards as the connecting cable makes removing just one difficult (if not impossible). There are 3 screws in the video board plus the 4 hex screws by the VGA and DVI connectors. The power board has 4 screws plus 2 black screws by the AC input plug, AND there are two silver screws on the backside which hold two heat sinks in contact with the metal cage. Finally, the video and power boards are free.
Immediately I noticed 2 bulging caps on mine, located at C127 and C128. I also noticed this monitor has a lot of capacitors in it. Typically a monitor power board has 5 or 6 electrolytic capacitors in it, but this monitor's power board has 20 (not counting the big reservoir capacitor). This monitor has a mixture of CapXon and Su'scon caps. I used my ESR meter to test all the caps and only those two were bad (ESR of about 89 ohms). But given those caps failed in less than 3 years time, I decided to replace every caps on the power board (again, excluding the big one). I used all Panasonic EB series (or FM series where EB series were not available). This ended up being a more expensive repair at $13 including shipping.
After replacing all the caps and reassembling the monitor, it powers up first time every time.
Hopefully this review of my repair helps someone else.
This monitor is noticeably newer than previous monitors I've worked on. Most monitors I've worked on are from about 2005, but this monitor dates to 2008, which means it failed in the 2 - 3 year time span.
Disassembling the monitor is a bit of a challenge. You start by pressing the button on the back of the screen which releases the stand. After you remove the stand there are four screen in the back of the monitor (behind where the stand was). Next flip the monitor over so the screen is facing up. Now the tricky part. You need to pull/pry the black bezel up away from the screen. To do this I used one hand to pull up on the screen from the inside of the bezel (I got my fingernails between the bezel and the glass of the screen). At the same time I used a screwdriver in the other hand to pry at the bezel from the outside. The trick is to pry the silver frame away from the black bezel. You need to start on the side of the monitor furthest from the controls. Next work the top, then the other side. Finally you can work the bottom, but be careful the of the circuit board for the controls. The wire is soldered to the circuit board and there's very little slack. Once the bezel is free you can remove three tiny screws holding the circuit board to the bezel. This multi-part video shows the disassembly I've described thus far.
Next you can lift out the screen. To remove the circuit board cage you need to remove all the wire connections, and there are 4 screws holding the cage to the side of the panel itself. Be careful with lifting up the screen, you must slowly lift it up and reach underneath to disconnect the LVDS ribbon cable.
Finally you can remove the circuit boards. You need to remove both the video and power boards as the connecting cable makes removing just one difficult (if not impossible). There are 3 screws in the video board plus the 4 hex screws by the VGA and DVI connectors. The power board has 4 screws plus 2 black screws by the AC input plug, AND there are two silver screws on the backside which hold two heat sinks in contact with the metal cage. Finally, the video and power boards are free.
Immediately I noticed 2 bulging caps on mine, located at C127 and C128. I also noticed this monitor has a lot of capacitors in it. Typically a monitor power board has 5 or 6 electrolytic capacitors in it, but this monitor's power board has 20 (not counting the big reservoir capacitor). This monitor has a mixture of CapXon and Su'scon caps. I used my ESR meter to test all the caps and only those two were bad (ESR of about 89 ohms). But given those caps failed in less than 3 years time, I decided to replace every caps on the power board (again, excluding the big one). I used all Panasonic EB series (or FM series where EB series were not available). This ended up being a more expensive repair at $13 including shipping.
After replacing all the caps and reassembling the monitor, it powers up first time every time.
Hopefully this review of my repair helps someone else.
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