The Samsung 204b has been a great monitor for me for years. Recently, it has started to take longer to “warm up” before displaying anything. It got to the point where I would turn it on, or move the mouse to wake it up, and then wait up to a minute or longer before anything showed up on the screen. Finally, yesterday, it just stopped displaying anything. The indicator light that signals power was on, but nothing was displaying on the screen. It was time for a repair.
The first thing I did was google “samsung 204b repair” and I came across this website:
Among other things, it showed me that CapXon capacitors on the power supply board were the most likely fault, repair was possible and pointed to a mouser cart that already contained the necessary parts. As it turned out, I only needed to replace the two bad capacitors that are endemic to this brand of monitor: C110 and C111.
I feel I should add this warning. Capacitors can be dangerous, and in some cases even deadly. Please use caution when working with circuits and understand what capacitors are and how to discharge them safely before continuing. I am not responsible for what you do based on this blog post you found randomly on the internet 🙂
Read on for a step by step guide to repair the Samsung 204b.
I don’t want to get rid of this monitor, imagine having to track down all those decals again for the new one!
Front view, sorry about the blur.
The first step is to jam a screwdriver into the crack near the buttons and try to find out where the plastic tabs are that keep the monitor together.
Clearly the tabs are on the bigger side, so I have to pry in this direction.
As I pop a tab, I continue down the side of the monitor until the whole bezel is loose. Some of the tabs break, but that won’t keep the monitor from staying together later. If you want to be really careful, there are tools that facilitate this process. I only used a common screwdriver.
This is a two-handed job. One hand holds the bezel, the other takes a picture.
The buttons are connected by a thin wire, which can be disconnected from the main body after I remove the back section of plastic.
And here it is without the front or back case. There are six screws to remove. Two on each side and two on the upper left seen here.
Do not lift here! Instead, lift from the corners. I made this mistake while taking the picture before I realized I was lifting the whole circuit board instead of just the frame. The frame can be lifted off by itself.
Aha! You can see that the two caps in the middle of the picture are swelling from the top. This is a clear indication that they are bad according to the website.
In my monitor, only these two caps were bad, lucky for me.
The caps are numbered C110 and C111.
The board must still be liberated from its case by detaching two cables on the right and one on the left, unscrewing four screws, and gently lifting the board out of the case. Then, set the case aside and get ready for some soldering. Be careful not to touch the capacitor leads until you have discharged them (see http://www.repairfaq.org/sam/captest.htm).
Here are the target caps, C110 and C111 from the back of the board. My mission is to desolder these four connections, bend the pins back, and remove the caps.
Done, and new caps soldered in place. You can see the new ones I bought were too big for the space, but still fit nicely with all the room around them.
The original caps were rated 820μF, 25V. The new ones are 820μF, 50V, which I read was fine as long as it’s rated above the voltage you plan to use.
I laid one of the caps flat against the board. There was lots of room and positioning it this way prevents any kind of problem closing the case. I didn’t have a lot of clearance above it. Just make sure none of your leads will touch anything metallic, or there will be problems.
With the caps in place, I put the board back in its spot, plugged in the cables (3 on the power board, plus one attached to the bezel for the buttons) and put the monitor back together. Now comes the true test. Will it work?
Success! The whole project took about an hour and a half for me, and I have no experience with this particular monitor. A very easy fix for someone who is careful, dedicated, and knows how to solder.
Hope you find this informative.