AOC AG493UCX 49-inch monitor - Firmware request

[wattage]

Hello Badcaps Community,

I purchased a preowned AOC monitor that is not working and out of warranty. It was sold as not working. I am looking for guidance on self-repair. In particular, I am after the firmware for the monitor. At the end, I have included monitor model information and links to pics and vids of the issue.

The problem is that it will not display a picture on any of its inputs. And the on-screen menu does not appear. The power button works properly. It powers on with the remote as well. But the on-screen menu does not appear, even when not connected to any input source.

It receives power. The backlight lights up. And it is recognized by multiple computers correctly (Windows 11 desktop computer, MacBook, Linux on old Lenovo ThinkPad).

I have tried multiple HDMI and DisplayPort cables on all the inputs and all the computers. The display is recognized on all, but does not show a picture - even when multiple computers are connected at the same time on different inputs.

I have installed current versions of both G-Menu and I-Menu (AOC's monitor management software). And have used both to factory reset the monitor. The issue persists.

The seller also had purchased a replacement mainboard and two replacement TCON boards. I have swapped these in with all combinations and all produce the same result. Power on. Backlight turns on. Black screen. No OSD menu. But all are recognized by the computer when connected.

I would like to install new firmware in hopes that it could help. But I do not find the firmware on the AOC support site. I hope someone here has it.

Please tell me what I should try further. Is there a way to do some sort of full reset on the monitor using the buttons or the remote? Again, I do not see the OSD menu. So I will need a sequence of buttons on the remote to press. Or some software/firmware to help.

Also, please let me know which chip(s) need to be flashed. I found a Winbond chip (25Q16JVIG, 1841, 6824, 4L700) on the TCON boards. And there are many 8-pin chips on the mainboards. But I'm not certain which is the firmware chip.

AOC LCD Monitor
Product No: AG493UCX
Model No: 493UCX
Barcode 1: HVPODF2KAPA6DN
Barcode 2: QKKMAJA000004B
Manufactured: 2021.10

Link to Google Photos album with pics and vids of the issue.
https://photos.app.goo.gl/fV7kMCEntB15DpMeA


I appreciate any details and help you can provide.

Thank you!

[Agent24]

Did anyone check the PSU is working properly? Maybe there is some missing voltage rail or something.

If the firmware was the issue, surely the replacement mainboard would have fixed it?

[lotas]

Most likely the problem is in the panel itself, you can see the photo of the lower part of the panel itself, where the buffer strips are located.

[wattage]

Agent24 - I thought the same on the firmware when switching the mainboard. But felt a firmware flash couldn’t hurt. I haven’t checked the PSU yet. Honestly, not sure how. Do you know of a guide that shows how to check it safely and properly? I thought it was ok since the backlight was turning on and the input from the mainboard was recognized by the computers.

lotas - Which photo are you talking about? Do you think it can be saved? Seems an awful shame to render the display useless. Any thoughts on the firmware?

[Habble7]

I don't think a firmware update will help here; the problem seems to be with the display panel. It looks like one of the panel drivers has failed and is causing an error state, which in turn prevents the TCON (Timing Controller) board from outputting a picture. Another possibility is liquid damage to the information transmission pairs (LVDS or eDP). If even a single trace is broken, the picture won't display. It would be helpful to see photos of the connection from the TCON board to the display panel's ribbon cables. Also, there are ribbon cables between the panel's internal boards; it's worth disconnecting and cleaning them with isopropyl alcohol. However, you must be extremely careful, as the drivers are on flexible circuits bonded to the glass. Do not damage them during disassembly, as those chips are very fragile.