LVDS PC "Standards" - Page 1
Forum section: electronics / projects

author: starhawk
author_rank: Regular Contributor
timestamp: April 01, 2020, 11:20:17 pm
content: Hey guys... I'm trying to cobble a computer together for my mother. This isn't usually too hard, but this one wants to be an adventure in all the wrong ways >_<For an idea of my experience at hand --https://imgur.com/a/b9ItI7HSo what I have right now is the component parts of an MS200-series "All in One" from HP and the same from a Wyse (now spelled D-E-L-L and probably not any better!) Z90D7 "thin client". Air quotes because the Z90D7 comes with SATA and an AMD G-T56N CPU, and *real* thin clients are 32bit, usually mostly VIA under the hood, and have only notebook-style IDE headers (*unpopulated* SATA connector footprints are occasionally allowed within that definition, such as in my HP T5630w).Meh.A bit of background on the MS200-series system (and why I'm not giving it a proper model number) is unfortunately necessary. I got it from a friend of mine who runs the local tech shop. He had diagnosed it with a motherboard failure, but because -- as he accurately describes it -- "all-in-ones are put together just like laptops, except there's no main battery and the parts are almost impossible to find at best". This is one of those, and it seems to have had issues in the past, because it arrived with uhm the wrong motherboard in it. Oh dear.The *case* ID's the system as an HP MS237. That properly comes with a "CapironaD" motherboard (take note of the "D"!), which has a Socket AM3 CPU supported by AMD's m780G chipset with integrated graphics (meh) and a pair of RAM slots with a maximum capacity of 4gb. This is paired with a "yooooooooge" 1366x768 LCD panel, a 500gb platter drive, and a laptop-style DVD SuperMulti drive that is of course Lightscribe capable because this is an HP and Lightscribe is very much their thing. Also, the RAM is maxed out at the factory and the CPU installed is supposed to be an AMD Athlon II X2 250u "Ultra-Low Voltage" CPU. However... when I got this thing, it had a *different* mobo in it... a "Capirona" (no "D" !!) which has an AM2 CPU socket for eg an AMD Athlon64 X2 325 and a minor cosmetic difference elsewhere on the board (the audio-our port on the *back* of the system happens to be black on the non-D Cpirona board). It also had an AMD Athlon II X2 350e CPU... and a rather incoherent BIOS. I could not re-flash the BIOS because HP has rendered that particular ROM image inaccessible to the public.Hence the desire for a guts-swap.The LCD communicates via a 30pin LVDS connector. There is a socket on the Wyse motherboard which is *physically* compatible with the HP's connector. It looks like the very common 40pin Hirose "LVDS Connector" but shorter. However, I know that the LVDS specification does not define a standard connector or pinout, or even make suggestions as to such -- so any "standards" in that regard arede facto"standards" and thus merely engineering convention.I have no way of properly ascertaining the pinout of the HP 30pin connector without either (a) spending several hours with a multimeter and a datasheet or (b) proper access to internal-only HP documentation. Neither is likely, and the Wyse board presents a similar issue which is complicated drastically by the fact that it is an *output* port and therefore determining pinout is not a matter of simple repeated continuity tests but rather consulting perhaps *several* datasheets for chips that may or may not have publicly-available information at all, as well as a considerable quantity of hopping about the mobo.While I know that the 40pin port is ade factostandard, I'm wildly unfamiliar with the 30pin form. Can someone tell me the approximate likelihood that the two connectors (one on the LCD cable for the panel, and the other on a motherboard from a completely different manufacturer) have identical, or at least compatible, pinouts, such that the Z90D7 mobo will likely drive the LCD just fine without any further adjustment, simply by plugging in the cable from one to the other? Also, the backlight is CCFL and thus needs an inverter. I have the original inverter, and I need to know how I could go about hooking that up to the new board.

author: starhawk
author_rank: Regular Contributor
timestamp: April 03, 2020, 02:52:47 am
content: No replies...? I'm surprised... I know this is kinda a PC thing, but I'd think a place like AnandTech would be *less* likely to know...

author: dmendesf
author_rank: Frequent Contributor
timestamp: April 03, 2020, 03:21:03 am
content: See if this helps:https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.intel.com/content/dam/support/us/en/documents/motherboards/desktop/sb/e77911001.pdf&ved=2ahUKEwjYyteEpsvoAhVVIbkGHUUpDJEQFjAOegQIAhAB&usg=AOvVaw3lKlPufmxipHGPVpFgWpOa

author: starhawk
author_rank: Regular Contributor
timestamp: April 03, 2020, 11:52:58 pm
content: Thank you! That tends to make a fairly strong suggestion, at least.But, as I said, the motherboard and system were originally HP, and the donor motherboard is a Wyse model. The Wyse Z90D7 design was released in 2011 or 2012, and Wyse was acquired by Dell in 2012...Since none of those brands are Intel, and both systems use AMD CPUs... I'm still not 100% on this. Can you or anyone post further information that would suggest that this is a "de facto" standard...?

author: kjr18
author_rank: Regular Contributor
timestamp: April 04, 2020, 10:19:25 am
content: LVDS are also two or one channel, 5 or 3.3V and even 6 or 8 bits. If you have part number on your panel, you could look up some info on them at panelook.com

author: starhawk
author_rank: Regular Contributor
timestamp: April 05, 2020, 05:47:30 am
content: Ugh, Panelook. Paywalls suck, dude...Here, have a datasheetdatasheets are good for you.LTM185AT01.pdf(1578.18 kB - downloaded 101 times.)

author: starhawk
author_rank: Regular Contributor
timestamp: April 08, 2020, 03:42:09 am
content: Still looking for further confirmation... anyone?

author: starhawk
author_rank: Regular Contributor
timestamp: April 13, 2020, 06:43:59 pm
content: I'm still looking for confirmation on this, that there's ade factopinout standard, even though there's node jureone.I'd just, you know, "try it already!" -- but if I get sparks, that's a major problem. I absolutely cannot afford right now to replace either the motherboard or the LCD panel right now, and this build is to be a gift for someone else. I can't put an apology in a pretty box under the Christmas Tree for this, not unless I want a tanned hide (nope)!

author: starhawk
author_rank: Regular Contributor
timestamp: April 18, 2020, 08:56:39 am
content: Fine, never mind... /sighProject terminated due to lack of sufficient information.