Please Note: Clicking on an image will take you to a higher resolution version of the image you clicked on. Perfect for viewing on a high resolution color-calibrated monitor like the one dissected below: *sniff*

2024-04-14: Alas, I knew you very well. I spent hours a day with you, gazing at you and pondering all the things you showed to me; all too soon you were taken from me in a senseless accident - never again to display your beautiful colors for my eyes to behold! *sniff* Wait did you say there were no repair parts available and that we're just going to recycle this monitor in the great big recycling center in the closest town? and then go out and buy another similar one? *sniff* So I can tear it apart and gaze one last time at it and figure out how it all worked? *sni....* Let me get my tools!

Sorry about the emotions on display above... This is the mortal remains of the monitor. Unfortunately a good third of the screen is unresponsive after an unidentified object hit it. No idea what and no idea how it was launched. That white dash on the left middle of the screen is the impact point. My image isn't the best at displaying the hairline cracks going every direction. I'm also trying to stuff a 24" monitor in a a 24x24x30" lightbox, so images may have some interesting perspectives as well.

This is the back of the monitor... There's a VESA Mount, a couple buttons (hidden nicely in the dark area), an unidentified and unused theft prevention cable securing slot and a sticker.

Closeup of the label and serial number. Monitor is still under warranty, but warranty doesn't cover this type of problem...

First step of business is to remove the back cover... Here's a hint: use a pick/spudger type tool to pry in around the left, top and right of the monitor... Work carefully, but leave the bottom until last. Red arrows highlight the easy plastic clips.

These are the clips on the bottom... There are a couple missing. Prying on the bottom end is rather pointless.

On the back of the monitor there are 6 buttons to control the monitor's onboard displays. This is the back of the circuit board that holds the buttons

And this is the business end of the circuit board... Strangely, this circuit board is very easy to remove; it almost feels like you could pop it loose by pressing on the buttons too hard. Certain eagle-eyed people may notice that the power button seems to be missing the 'button' part... I can't find it anywhere in the monitor or on the bench. If you look very closely at the circuit board, you might also notice that some of the button outputs are tied together with varying resistances on the outputs. This seems to be a way to save a couple wires...

This is what the inside back of the monitor looks like. Everything is covered in shielding, except for a ribbon cable, some other wires for the backlight and a label (which we'll show later when it is fully exposed).

Also pretty sure I forgot to show the port selection. (left to right) HDMI x2, Displayport, Mini Displayport, Displayport, Audio Ouput, USB 3.0 input, USB 3.0 Output x4

One of the selling points of this monitor is its 'frameless design'. After removing 12 screws from the plastic bezel, we're left with the plastic frame around the monitor. The 'frameless' design adds 1/16" on each edge to the if we could remove this bezel, it truely would almost be frameless! (there is still a metal edge/frame on the LG portion of the display - light leakage would be a problem without it!)

here is an image of the sticker on the LCD Panel. It is manufactured by LG Display, model LM238WF4-SSH1; not quite sure what the 'LP-238H1-0-S-Z-PA-8-HZ-Q-19R-01Y8' references yet. There a couple of these panels on eBay for $270 or so. All out of China... Not sure I trust the sources enough to spend that much on a repair and then still need calibration yet...

After removing a metal shield, we can finally view the LCD printed circuit board. There is an amazing amount of wiring packed into this board.

The circuit board is dominated by two chips, one of which is a 48 pin chip labeled 'SM4047D DA2125 SMNS119'. I wasn't able to find a datasheet for this IC.

This little chip is labeled 'LG Display SW0679 01SWL-0202A' and is housed in a QFN48 package.

Right next to UC1 (LG Display IC above), there is a smaller IC labeled 'GT 404A-2ZL1 128'. Possibly a GT24C04A 4Kb EEPROM?

And there's one other oddity on this board - a cutout for a couple capacitors. There has to be a reason for this, but I'm at a complete loss here on the point of isolating these capacitors like this.

and lets not forget all four of these unlabeled ICs on the ribbon cable leading to the actual LCD screen. There are some very cool looking wire patterns on the ribbon cable and some even finer wire pitches! This whole flexible cable is 1.115" in width. There are 100 pads/wires coming from the green circuit board and maybe 750 going out of each cable? (1920 columns + 1080 rows)/4

The metal cover in the center contains these two circuit boards. I've gone ahead and removed the ribbon cable for the LCD screen and also a black high voltage plastic shield for visibility.

Power Supply Board Top, Viewsonic Part Number B-00013434. Looks to be a fairly standard design. Chip marked PU801/HT801 is labeled 'GB98ADN CM5827.1N 2039A2' which appears to a 4-string high power LED driver/controller. These outputs are the Black/Brown/Yellow/Green wires off to the left. Ground is the two center Red/Orange wires. Upper-right connector is similarly simple. Black is Backlight Enable Input; Brown is Backlight PWM Input. Skip a Pin. Next 3 wires (Red/Orange/Yellow) are +19VDC and the bottom 3 wires (Green/Blue/Purple) are 0VDC/GND. Should be easy to troubleshoot if needed.

Power Supply Board Bottom, Viewsonic Part Number B-00013434. PU501 appears to be the power supply control IC (Best guess at markings is '537ARG1N AN24R3.1G 2126B') Q801 appears to be an 'Alpha & Omega AOD2916 100V N-Channel MOSFET' in a TO252 DPAK package.

I/O Interface Control Board Bottom, Viewsonic part number B-00013433. Board markings show it as 'L5142-1 748.A1H02.0011'. I'm going to show the bottom first because all the interesting stuff is on the top.

I/O Interface Control Board Top, Viewsonic part number B-00013433. Power input from power supply is upper left; LCD ribbon cable top center and button board ribbon cable on the right.

First IC to look at is the Realtek RTS5411 USB 3.0 Hub Controller. Datasheet (PDF, 33 Pages, 872KB) can be found here. 12Mhz crystal lower left and U1903 (better picture below) in upper right.

U1903 which is a MXIC MX25L2026E 2Mb CMOS Serial Flash. Datasheet (PDF, 48 pages, 548KB) can be found here.

Second IC (and largest) is the Realtek RTD2775TM. I'm assuming this is the SOC, but I'm coming up empty on a datasheet for this one. You can see U304 in the upper left and U303 (below) appears to be the Flash chip for this SOC.

U303 is a MXIC MX25L1606E 16Mbit CMOS Serial Flash. Datasheet (PDF, 60 pages, 2.95MB) can be found here. I can't seem to ID U304.

U1202 & U1204 are labeled FM24C02C and appear to be 2048 bit Serial EEPROMs. Datasheet (PDF, 23 pages, 973KB) can be found here. Wires trace to the HDMI ports and are probably related to EDID.

and there are three tiny little strange chips (PU2201, PU2205 & PU2206) labeled AVIDVP. (Makes me think AVID Video Processor...) They are very odd 11 Pin devices. There are 3 rather large capacitors beside each chip which stand out like sore thumbs. Whatever these chips do, they require a nice bit of power as evidenced by their pads and vias!

We have to look at the backlight as well - it is mounted on the bottom edge of the screen and uses the metal backplate as a heatsink.

'65 238WF4 Rev 0.2 AG-D1 94V-0 2128' (not shown in photo) 'VJ6H57JG VJ6H52A8'

6-Pin backlight connector

And last, but not least is the 6 layers which diffuse the backlight evenly across the whole screen. (sorry about compression - click on the image for a larger, clearer image)

This is the most interesting of the layers! Whomever designed this one has spent a lot of time on it! The dots play tricks with my eyes, but the dot size changes from bottom (smallest) to top (Largest). It is truly amazing how much design is involved in this one sheet! (this picture does not do enough justice to the design!)

This is the top edge; there is a reflector strip at the top. Dots are spread out and thin near the top.

This is the bottom left corner; There are some really large dots in the corner. Slightly larger dots along the left edge.

...and with that I'll probably call this one done... much curiosity was satisfied and many (unpublished) images were taken. If you have anything to add to the info on this page, feel free to use the CONTACT US PAGE to send comments or info! Unfortunately many of these parts will be recycled, so future questions might not be possible to answer... hope you enjoyed this and learned something new!

Psalm 69:14