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Today we’ll be looking at the BenQ 21.5″ E2200HD LCD Monitor which features a 1080p display, HDMI / DVI / VGA inputs, speakers and a headphone jack. This one stopped working one day, I’ve had it for 8 years so decided to take it apart to see what was wrong.


(forgot to take some pictures of it before I took it apart, so here’s a stock image)

After a couple of tough clips and removal of the stand, we’re in. There was a metal cage holding the power and logic boards but it was just stuck on with some shielded tape, no screws whatsoever which was odd. Powering it up by the power button, I can see the power LED turn on for a fraction of a second, does this 2-3 times before it no longer lights the LED.

Logic board

The logic board is a single chip solution, the RTD2482 which supports VGA (RGB), Component (YPbPr), HDMI, DVI and DisplayPort 2A+2H with an audio DAC, infrared controller and supports resolutions up to 1920×1200 resolution. Running from a 27MHz crystal.

There are un-populated connectors on the board, 2 on the top right and 2 on the bottom right, one spot for USB (with a separate power rail for it) and an ethernet connector. The first regulator on the board is a 50117-K 3.3V LDO and second one a AS1117L-12 1.2V LDO, both of which decent heatsink pads which includes the bottom of the board.

We have a few EEPROMs around, 3x ST 24C02 2Kbit, a ST 24C16 16Kbit some of which I believe would be for the display inputs so video cards could identify the monitor and a MX 25L2025 2Mbit serial flash.

Power board

For the power board we have 2 main outputs, the LCD backlight and the 5V for the logic board/5V for the USB port (not populated). There is a beefy 450V 105C capacitor and a few different brands for the other capacitors (Lelon, Jamicon, Su’scon). The SPW-101 transformer seems to have 12.6V and 6.3V taps and to generate the 5V output they use 2x SB1060 schottky rectifiers.

We have the audio output near the bottom right with an Anpec APA2069 stereo 2.6W audio power amplifier (with 32 steps of volume adjustment). The LCD driver is the MPS MP1009 which drives 4 lamps with 2 N mosfets.

For the high voltage series transistor they wanted to keep the isolation, so they had to bend the middle pin over the isolation slot.

One weird thing is that there is a metal strip between the LCD backlight and near the mains, I don’t know if that is supposed to be a shield or something else, it’s wired to earth, just looks a bit odd.

Troubleshooting

In terms of troubleshooting, all the capacitors looked good so I moved over to checking voltages on the logic board. The 5V input rail seemed good at 4.8V but the 50117-K LDO was giving out 4.5V which was a bit strange, why would you bother dropping 0.3-0.5V but then I checked the datasheet which says the K version should output 3.3V so it’s definitely bad. The 1.2V LDO was ok. No ICs look fried and nothing really gets hot, so there might a chance everything is ok (most ICs on board seem to be rated for 5V).

Swapped out the 50117-K LDO for another 3.3V LDO and the power LED stays on now. I connected it all back together and it’s working fine!

7 Responses to “Inside and Repair of the BenQ 21.5″ E2200HD LCD Monitor”

  1. Andrew says:

    Hey, I’m trying to open a monitor like that right now but im having a big trouble with the clips. Do you remember by any chance how you got this thing to open?

    • Alex says:

      Hi Andrew, I don’t remember the specifics but I started from the bottom where the silver bezel is, used a flat head screwdriver to pry it apart (left some marks) and slowly continued along. The stand needs to be removed, there is a silver plastic cover hiding the screws.

  2. Tom says:

    Hello, i have problem with this monitor, after ON show logo, few second black and few second show Desktop and black. Power LED stil ON. I replaced condensator C819 because he wasnt good and C820,C823 preventively. But problem is still the same. 50117-K seems OK too 4,67V/3,20V. When he shows i hear a faint whistling but i dont know where. Can you help me?

    • Alex says:

      I’m guessing the sound is coming from the power supply board?
      I would double check all capacitors and test the voltage going into the logic board when it goes black, does it drop out? I’m thinking it probably doesn’t as it would show the logo again, so I think it might be the inverter or bulb.

      This video might help with troubleshooting – https://www.youtube.com/watch?v=Dh01ZepjDp0

  3. Florian says:

    Hello,
    how do you opened the frame?
    There are no screws.. The only thing I got lose is the silver bottom plastic trough two holes from down side to open the hooks. There I came not any further with opening.
    Thanks

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