Samsung SyncMaster 204B LCD Repair

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I have five Samsung SyncMaster 204B 20" 1600x1200 monitors that I've acquired over the years, two of which recently developed the problem with the backlight. My main impetus for repairing instead of replacing them is that I *really* like these monitors, and it's getting harder and harder to find a proper 4:3 aspect ratio monitor. I've used the widescreen monitors, and I intensely dislike them. 16:9 is for movies, not for programming.

Four of these monitors were purchased at one time as refurbished units, and the other was a hand-me-down from my company. Recently the hand-me-down and one of the refurbs exhibited the classic backlight failure problem (not coming on at all, coming on for a few seconds, maybe eventually staying on, sometimes at a reduced brightness). Searching around on the 'net turned up this handy page,

I ordered the parts (shown below) from DigiKey and in about 30 minutes for the first monitor and 15 minutes for the second, had both repaired. I won't bother repeating the instructions that Pavel has on his page, as they're quite good. The only additions I will add is that the corners can be tricky, and if you don't work slowly and with a narrow tool, you may break the internal tabs. This isn't catastrophic, as the edge clips will still hold the monitor together, but if you're a perfectionist, it WILL annoy you. Also be very careful as you lift the bottom of the front bezel off. There's a small 4 conductor cable that connects the bezel to the chassis. You'll have to work the back shell off so you can get to the connector to disconnect the bezel. Here are some photographs from a 204T Icon-pdf.gif (6.42 MB), which is very similar.

Pavel mentions that his capacitors were manufactured by CapXon. Mine were made by VOA. The replacement caps I ordered are all made by United Chemi-Con.

Since I have five of these monitors, I ordered enough parts to fix all five. I opened one of the monitors before I ordered the parts to verify the specifications for the capacitors. It was a revision 0.0 board, and the other turned out to be also. There are revision 0.1 boards out there, but I suspect my monitors are old enough to all have the 0.0 boards.

Revision 0.0 boards need the following parts:

  • (2) 820uF/25V Capacitors (C110, C111)
  • (2) 680uF/25V Capacitors (C304, C305)
  • (1) 330uF/35V Capacitor (C112)
  • (1) 47uF/50V (C107)

Revision 0.1 boards need the following parts:

  • (2) 820uF/25V Capacitors *(C110, C111)
  • (3) 330uF/35V Capacitors *(C112, C304, C305)
  • (1) 47uF/50V (C107)

You may also want to replace the 100uF/450V (C105) capacitor. The ones on my board looked OK (although Pavel replaced his simply because they're made by CapXon). I was feeling cheap, so I skipped those. Something like this 493-2074-ND should be correct, although double check the lead spacing. If you do replace it, be sure to glue it back down. Use RTV that is NOT acetic acid based, or use two-part epoxy.

Removing the old capacitors is easy enough with a decent soldering iron. Using some liquid flux (like a flux pen) makes it a little easier. Use a solder sucker or solder bulb to remove the heated solder, then install the new capacitor (observe the polarity!), apply a little flux, solder, and trim the leads. I suggest doing one at a time if you're not entirely comfortable with this. Use a Q-tip with some denatured alcohol to remove the solder residue.

I also ordered enough parts to meet the 10 piece price break. I build enough little electronic projects that having a few extra caps around doesn't hurt. I also don't like to pay the $5 fee for orders under $25, so I padded it up with some additional parts for a solar battery charger I'm building for my motorcycle (I don't ride it enough in the winter to keep the battery charged).

Quantity DK P/N Description Unit Price Total
10 565-1553-ND CAP 820UF 25V ELECT KY RAD 0.45900 $4.59
10 565-1551-ND CAP 680UF 25V ELECT KY RAD 0.36900 $3.69
10 565-1984-ND CAP 330UF 35V ELECT LXZ RAD 0.49200 $4.92
15 565-2004-ND CAP 47UF 50V ELECT LXZ RAD 0.31500 $4.72