I have discovered something particularly interesting that may be relevant to the interests of people hoping to mod 2C's to 2B's. I am temporarily in posession of stryker7314's 2B DVI board while I attempt to repair his damaged backlight driver circuitry (probably just a blown mosfet or something). While I was examining the board though, I noticed something particularly interesting. A couple pictures will illustrate well:
Here's a close shot of the DVI to eDP portion of my 2C DVI board:
Warning: Spoiler! (Click to show)
And here's an equivalent of stryker's 2B DVI to LVDS board:
Warning: Spoiler! (Click to show)
If you examine these two boards closely at this section, you'll probably notice that the big main chip (which is a DVI receiver made by Explore Microelectronics) is present on both; immediately to the left of this chip on the 2C board however is a second chip, labeled IT6251. While I'm unable to find a datasheet on this particular part, I can make a pretty good guess based on the manufacturer's products combined with its placement on the board; it's a 2-channel LVDS to 4-lane eDP converter chip. Why do we care?Because it means a 2C PCB has all the important components already there to drive a 2B panel and timing controller.
Now, closer examination of the boards reveals that in the 2C they're only using half of the output LVDS lanes (running in 2-channel mode) provided by the EP269 compared to the 4-channel mode on the 2B (indicated by the larger number of resistor packs marked 750 on that board). I don't have a datasheet yet for that exact chip, but a closely related datasheet (EP263) shows that mode selection between output formats is simply chosen by holding a couple pins high or low. By modifying these mode pins on a 2C board's chip and rewiring the output from the chip, we can drive a high refresh T-con by bypassing the ITE LVDS-eDP converter altogether
Now, this is obviously a highly skilled and labour-intensive mod; you'd need to desolder the 750ohm resistor packs to detach the output from the EP269, solder the mode lines to whatever is required to enable all 4 output channels, then solder a few ribbon cables from the left half of the EP269 to a small daughter board containing a few passive components and a couple 2B style connectors. Once *that* is done though, all you need is a source for the two cables and a T-con (which there seem to be a couple viable sources through taobao, I'll update later with my experience here letting you know if it's a valid way to source the boards) and your previously 2C monitor should overclock with aplomb.
I know this is probably over the heads of a lot of the people reading here, but the take-away point is that assuming you can find somebody with the soldering skills (I doubt I could do the mod for all those interested, although I can pioneer it and produce a guide) it's actually possible to convert a 2C DVI board into effectively a 2B DVI board, solving half our problem (and all of it if you can get a T-con). Sure, it'd be easier if Scribby can source the boards and we can do a drop-in replacement - but worst comes to worst there *is* another way
I still need to scare up a copy of the EP269's datasheet, so if anybody comes across it *please* let me know!
As a bonus, while examining the boards and connectors I was able to pin out the LVDS connectors on the 2B PCB
if it's useful to anybody. Combined with the SLA1 datasheet
, this allows you to reproduce the cables fairly easily if we can't find a ready-made source.