Thinkpad R50e display not working

[Indianer]

The display on my laptop (XGA) went dead so I acquired a substitute on ebay which will not function either. I replaced the inverter as well with no joy. Since the inverter I require (27K9949) is not easily available, can I use an inverter 39T0019 which is actually meant for an XGA/SXGA+ display?

[Harryc]

Since the inverter card FRU# 39T0019 is listed under the XGA parts section on the R50e parts list, I'd say yes it is compatible.
http://www-307.ibm.com/pc/support/site. ... html#15xga

What is the FRU# of the LCD you got from EBay? Does anything display at all on it, even a dim image? Use a flashlight to see it if needed.

[Indianer]

Thanks for the prompt response, Harryc. The FRU# of the LCD I got from eBay is 92P6678.

Both the old as well as newly acquired LCDs display outlines and dim images when booted up. Is the:

- video chip on my mobo defective? I however get a clear and normal picture of my laptop when connected to an external display.
- Is the inverter defective? I replaced the inverter in the old display with the one from the new display. No joy! Also, a closely held bulb to the connectors on the inverter does not light up.
- Is the LCD ribbon cable defective?

[Harryc]

It is possible that the Laptop's LCD lid close switch is stuck in the closed position.

[Indianer]

Thanks Harryc but I had dismantled the complete laptop including the LCD panel which meant removing and re-installing the Lid latch. Can the lid close switch still be stuck and in two LCD panels? I'll check it out but my bet is more on the LCD cable.

[Harryc]

The lid switch in an R50e is not in the LCD panel, it is in the base. There should be a small protruding plastic piece on the LCD bezel that makes a switch in the base when the lid is closed. The switch is located on the right/back side of the base on the keyboard bezel.

[Indianer]

Thanks again Harryc. Would the lid switch not come unstuck if/when the keyboard bezel is removed? As I mentioned, I had completely dismantled the laptop before disconnecting and dismantling the LCD panel. However, I shall do so again and check.

[Indianer]

Well, after acquiring two replacement displays, it turns out that the inverter was faulty (FRU# 27K4999) in my R50e type 1834--BYG (also the ones in the replacements). Can I substitute any others and if yes what are the FRU's?

Thanks in advance!!

[Harryc]

There are (3) inverter FRU's listed in the LCD Service Parts listing - ThinkPad R50e, R51e, R52 . The first 27K9949 is listed as Inverter card, XGA. The second and third FRU's, 39T0019 and 39T0368 are listed as Inverter card, XGA/SXGA+. One would assume that both the second and third FRU's would work for a 15" XGA LCD since they are listed as compatible.
http://www-307.ibm.com/pc/support/site. ... 8947#15xga

[Indianer]

OK, I finally got a replacement inverter (27K9949) which was supposedly tested before. But my display is still very, very dim. I can only make out faint outlines of the desktop icons which was the status quo a few months ago. The inverter vendor says that my back light bulb is defective. Any suggestions?

[Bruce Guttman]

I have an R50 base that exhibits the same problem. It boots, but the display looks like the backlight is blown. This with two known good displays.

I suspect there is a bad fuse. Anybody know which fuse controls the backlight?

[RealBlackStuff]

Look at anyone of PoshGeordie's posts, he has a list with T4x fuses in his signature.
The R50 is virtually a twin of those mobos.

[Bruce Guttman]

I did. I even downloaded his fuse document.

I'm not sure which of the 4 fuses associated with the LCD controls the actual CCFL.

It really surprised me that two displays that worked fine on other boards showed up with no CCFL on this one.

Also, I haven't dug the Planar out of the carcass yet to see if the fuses on the bottom side are bad.