01-06-2012 09:10 AM - edited 01-06-2012 09:17 AM
See my note above about high temperatures. You need at least a quartz preheater and a good rework station (plus steady hands). The bigger fuse (3.18mm) is Littelfuse 433003 (3 amp, 32 volt). The smaller one (1.6mm) is Littlefuse 434500 (.5 amp 32 volt). I don't know a good source. Sometimes they are available at Mouser.com. I use organ donor boards if I fix them.
01-06-2012 10:27 AM - edited 01-06-2012 10:27 AM
Is there enough room to do something really tacky like bridging the blown surface-mount fuse with a leaded one? (leeeeeded, not led-ed) Using low-temp non ROHS solder?
Pretty shade-tree, but maybe in an emergency? Kids, don't try this at home. I'm asking, not saying...
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07-15-2012 05:23 AM
Hi richk and everybody,
I am having a similar problem with my T500. Backlight not working while everything else is fine. I seem to have blown it during the replacement of the magnesium display frame.
Where exactly can I find the fuse F7 labeled as a P. I have removed the keyboard and the front plastics. Do I have to remove the bottome plastics as well?
06-18-2013 09:53 PM
My T400 started this when I am trying to replace the LCD with another one. The new one came with its own inverter so I installed it and plugged in everything and turned on the system and screen is soo dim that you can barely see it and none of the lights come on except the WiFi.
I swapped the inverter with the old one that was working fine before and the staus is still the same, no leds except WiFi and display is dim (even using old LCD that has scratches on it and was working 100% funcationally before)
I looked under the LCD connector on the board and I saw two conponents right below the connector one towards optical drive (labels P and green in color) and another one towards the CPU (labeled F, aslo green in color). They look fine to me cosmetically, will check their continuity tomorrow.
Meanwhile if you guys have any suggestions, let me know.
06-19-2013 08:41 AM - last edited on 06-19-2013 08:51 AM by zoltanthegypsy
The tested both fuses and the big one appears to be fine as it has continuity, but the small one doesn't. This doesn't make sense why my backlight is also not working on both screens that I have unless I am looking at a wrong fuse.
I have highlighted the fuses that i am checking in the picture below. The one on the right appears to be fine, but not the one on the left.
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06-19-2013 01:05 PM
I ordered a couple of new inverter boards to see if its the problem that caused the fuse to burn in the first place. Will keep the status updated as I get them.
07-16-2013 02:39 PM
Turns out that replacing just the small fuse fixed both issues.. status LEDs and backlight. Now they both are working.
So, having a bad small fuse is enough to have both these issues.