**FOUND**: Thinkpad R500 15.4" LCD Cable 93P4451

[Harryc]

If you have a Thinkpad R500 15.4" LCD Cable, FRU# 93P4451 for sale, please send me a PM. Thank-you.

[underclocker]

So upgrading the LCD on an R500 requires a corresponding cable? If so, why would they use this desgin in the R500 series, when the Z, T & W series use the same cable for all resolutions? I'm pretty sure the 14" R61's had a universal cable, but I'm not so sure about the 15.4" R61's. What a hassle. I had hoped this was an design issue of the past, left behind with T4x and R5x machines.

[Harryc]

Well, I believe so. They have different part numbers for WXGA and WSXGA+ LCD cables in the R500 parts manual. I am not basing this on practical experience of any kind.
Here's my dilema...(2) available on EBay at $35 shipped. First of all that is highway robbery, second it's a decent percentage of the entire price I paid for the machine.
http://desc.shop.ebay.com/i.html?_nkw=9 ... c=1&_rdc=1

[underclocker]

...it's a decent percentage of the entire price I paid for the machine.

Outrageous! Have you tried the WSXGA+ LCD with the WXGA cable, just to confirm that it won't work?

[Harryc]

Haven't tried, but I will when the LCD comes in.

[erik]

sounds like a good way to fry something.

check the datasheets on your panels and match the LVDS pinouts before assuming everything will work.   matching connectors doesn't automatically mean pinouts will match, especially given different FRUs.   you could dump +3.3V to ground and wind up with a pile of useless parts, making that $30 cable not seem like a bad price after all.

[Harryc]

Too much work ... I'll pay the $30 Thanks!

[underclocker]

You could dump +3.3V to ground and wind up with a pile of useless parts, making that $30 cable not seem like a bad price after all.

True, true. But what about the value of adventure, experience and learning, not to mention saving other forum members (maybe even me!) from doing the same, some point down the line - or showing them the way? Go for it!

I didn't think twice before hooking up this 15.4" WSXGA+ Z60m LCD assembly to a 14" T60 base --> http://forum.thinkpads.com/viewtopic.php?f=11&t=91233

Perhaps I should have?!

[Harryc]

I love you guys like a brother, but I won't fry a new R500 for any family member .

[erik]

haha, well, there's a 95% chance it will work and 5% it won't.

problem is, that 5% could be costly.

(also, 87.5% of all statistics are made up on the spot)

[underclocker]

Very funny. However, all joking aside, I think it's a safe calculated risk. Here's why. We already know that the 15.4" panels used on R500's are standard panels and also sourced for other models like the T500 and W500. Additionally, they will work on Z60m, Z61m, T60, T61, and R61 models. They have standard LCD panel connectors and they have the EDID chip. The procedure of swapping the WXGA panel with an SWXGA+ panel won't reroute any signals from the existing cable. At worst the R500 isn't using EDID information to setup resolutions and will send a WXGA signal to the SWXGA+ panel, rendering a distorted or blank image. I suppose there is a tiny chance that panel damage would result, but I've never seen it (and I have connected incompatible resolution panels on T4x and R5x machines).

That's my theory. I woudn't hesitate to try it.

(Regarding my connecting the entire Z60m assembly to a T60, I had previously connected a bare Z60m panel to a T60's LCD cable and it worked. Therefore, I figured the pinout on the Z60m cable was the same - as was the cable connector. It was an educated guess that it would work. And it did.)

[erik]

keep in mind that the sockets at the planar end are all the same.   for example, you can connect an X61T panel and X61T cable to an X61 notebook planar with no problem.   but, if you connect an X61T panel using an X61 notebook cable, you'll dump +3.3V to ground and permanently damage the planar.   even though the cables use the same sockets at the planar end, the LCD ends are wired differently.

the only way to know if the LVDS cables are the same internally is to check the two cables with a multimeter and map out the connections or to check the datasheets on both the WXGA and WSXGA+ panels to see if the pinouts are the same.

there are two reasons why there are different FRUs for these panels.   either the sockets are wired differently or they're in slightly different locations on the LCD panel.   otherwise, if the same cable could have been used, lenovo wouldn't have spent the money to manufacture and stock a second batch of cables.

if someone can find the manufacturers and model numbers for the two displays, i can try and find the datasheets and check the pins.   the hard part is in finding the datasheets.   the rest is easy.

i agree that there's a better chance than not that this will work.   however, for me, a calculated risk actually involves a calculator.

[Harryc]

Well, here's the WSXGA+ Part # from LG - LP154W02 (TL)(10).

[erik]

i couldn't find a datasheet on that LG panel but did find datasheets for two samsung panels used in the T/R 500 thanks to this page on thinkwiki.   why i didn't think to look there four posts ago is beyond me.

the LVDS pinouts are indeed different.   the WXGA cable is missing connections for pins 20 through 30.

while the cable won't kill your system, you won't get a full signal.   it'll likely either be a black or garbled image (and i'd guess the latter).

WXGA: http://beyondinfinite.com/lcd/Library/S ... X3-L01.pdf (page 14)
WSXGA+: http://www.beyondinfinite.com/lcd/Libra ... P1-L03.pdf (page 8)

[Harryc]

Thanks erik

[underclocker]

erik, great detective work. I wonder if 1) a WXGA LCD would work with the WSXGA+ cable (since the first 20 pins seem the same), and 2) if so, why do they even make two different cables (other than to save a tiny bit of copper)?

It's really too bad a universal cable isn't used, like on all (most) other current ThinkPad models.

[erik]

if the WSXGA+ cable were universal between the two panels then there wouldn't be a need for two FRUs.   like most parts in these systems, there's a reason for everything.   i guarantee lenovo's engineering department would have preferred one FRU versus two or three.   it's not like they did this just to make screwdriver-wielding customers angry.

besides, the LCD panel manufacturers decide the pinouts based on how the controller board lays out.   PC manufacturers rarely have that finite of control over production.

[Harryc]

The cable has been purchased. Thanks everyone.