Backlight shuts off randomly, R61 15.4", 8930-A41 + WSXGA+

[glossywhite]

Hi guys


My thinkPad is: R61 15.4", 8930-A41


My LCD cable came from China today, and I fitted my official IBM/Lenovo WSXGA+ LCD... but randomly, and infrequently, the backlight will shut off, which seems odd, but if I sleep and then unsleep the machine, or reboot/power off and on, the backlight is up and running again :-/

Is the backlight inverter that was originally in my machine - 1280x800 LCD - the same power & spec as the one for a 1680x1050, WSXGA+ LCD?

[EDIT]

I found out the part numbers of the backlight inverters for the R61 15.4, and the R500 (WSXGA+ LCD) are the same:

Inverter card
All models 41W1482 R N
All models 41W1484 R N


R500 (1680x1050):
http://support.lenovo.com/en_GB/product ... MIGR-70465

R61 (1280x800):
http://support.lenovo.com/en_GB/product ... MIGR-68172

If anyone has any ideas, I'd greatly value some help. It doesn't happen all the time, but when it does it is very annoying.


Thank you

[ajkula66]

Two things come to mind:

a) A (Power Manager?) setting that turns the LCD off after a certain time of being idle

b) A failing CCFL

Good luck.

[glossywhite]

Two things come to mind:

a) A (Power Manager?) setting that turns the LCD off after a certain time of being idle

b) A failing CCFL

Good luck.

Hi

Nope, it's not a power manager - it happens on Win 7 *and* Linux Mint, and power saving is off on both. I've removed the bezel, and when I push/wiggle the multi-pin connector that feeds the low voltage side of the inverter, it seems to (sometimes only, oddly) make the backlight go off. I removed the connector, powered the TP off and dabbed alcohol into the connector and then let it dry. It doesn't seem to be doing it so much now, but I've reported the cable as faulty to my supplier in China - I hope they will refund/replace it, as this is pretty useless as it is.

My final test is to leave everything on the new panel connected *apart* from the CCFL, and connect the inverter to the CCFL of the "old" (brand new) 1280x800 LCD which I removed, and see what occurs.

[UPDATE]

Okay. I plugged the CCFL from my original LCD into the inverter, and the fault is still present. Seems like the cable...

Thank you for helping


[UPDATE, Tues 4th June 2013]:

Okay. I think I've found out what the issue is, by elimination. I have run multiple tests:

1/ LCD on lowest brightness, half an hour = NO blackout.

2/ LCD on full brightness, half an hour = blackout after around 10 mins. A sleep/wake cycle resets the inverter (a solid-state thermal trip, I'd suspect) and it comes back up *immediately*.


I've ordered a replacement inverter:

http://www.ebay.co.uk/itm/161003391360? ... 1439.l2649

It appears to be "Sumida" (FRU: 41W4184), as the one in my R61 (FRU: 41W4182) is FoxConn, and has a white insulating cover over the HT end, and the replacement, a transparent cover.

[glossywhite]

UPDATE AND SUMMARY
===============

New inverter arrived. I installed it, but the WSXGA+ backlight only works on mains power, and turns itself off when running on battery. Also, the new inverter seems to run hot on the WSXGA+ CCFL, as the old inverter did.

Summary: WSGXA+ screen's CCFL is drawing too much, so I've put the 1280x800 back in - at least that is reliable! Could the CCFL be too old and drawing too much? I think so.

[ajkula66]

Yep. That WSXGA+ panel has definitely seen better days. As predicted in my previous post.

[glossywhite]

Yep. That WSXGA+ panel has definitely seen better days. As predicted in my previous post.

You were right, and I was likely in denial (or over-optimistic). Thankfully, the eBay seller has given me £20 of the £24 I paid, back