R51: 1-3-3-1 beep w/o RAM but nothing w/ good RAM. dead MB?

[kctopitz]

I have a spare R51 that by all appearances is dead, but being the geek that I am, I've taken to trying to figure out what's wrong with it.

With everything plugged in/assembled, when you turn it on, the green LEDs come on, the CPU fan spins, but no video (including external) and the system doesn't POST (no beeps).

I went through and removed the battery, hard drive, optical, wi-fi, bluetooth module, touchpad and of course, the RAM modules. When I do this and power on, I get the 1-3-3-1 beep code, which I understand is a good sign. But... as soon as I install any one of four different PC2700 RAM modules (2 pulled from other systems, known good) it powers on but, just like before, there are no beeps and the system doesn't post or show any video on the VGA port. I've also tried putting the module in the bottom slot (user accessible) and it produces the same results.

I've tried plugging the optical drive or hard drive back in - no change. I've tried unplugging the BIOS battery and the LCD cable from the motherboard. Neither seems to make any difference.

So basically it seems that the system is recognizing that the RAM is installed, which is good, but then... nothing. Is it safe to say the motherboard is dead, or is there anything else I can try?

Anyone suggestions appreciated!

[kctopitz]

Still looking for suggestions.

[rkawakami]

Sorry, missed this the first time around . When you have connected an external monitor to the VGA port, have you also tried the Fn+F7 key combination a couple of times? In some cases, you will not see any video out the external until you do that. You may automatically get a signal from the VGA port if you connect the monitor and power it up prior to booting the laptop. However, the BIOS has to be set to VGA+LCD mode. If it has been set to Thinkpad LCD, then nothing will appear out the external video port unless you manually switch it there with the Fn+F7 sequence. Assuming that you get video out the VGA with the Fn+F7 command, then you can safely say that most of the motherboard is working.

Your system could be operating correctly but the inverter or backlight (aka, CCFL) is out, a fuse has blown, your lid switch is stuck or you have a major problem with the graphics system on the motherboard. This would leave your display "dead". You can verify some of this by shining a bright light downward on the screen at an angle. The best way to check this would be to power up the system (without an external monitor connected since you want the LCD active), press the F1 key to access the BIOS and then wait about 5 seconds for the system to get into the BIOS menu. Since the BIOS background is mostly white and the lettering blue, this will show up fairly easily with a flashlight. If you do see the BIOS menu, then again your motherboard is mostly working but you'll need to check the following:

- Flick the lid switch, located next to the left hinge near the back of the keyboard bezel. If it's stuck down, this cuts off power to the backlight. If the switch seems to be working, that is, it returns to the "up" position flush with the bezel, then continue on.
- If the display has had a pinkish/reddish tint to it recently, then that could indicate that the backlight is now dead. About the only way to verify this would be to swap in another LCD panel.
- A fuse on the motherboard could have blown. You'll need a multimeter to check the tiny surface mounted fuses. If you get this far and need some help identifying them, holler and we'll supply some more direction.
- The inverter board, which supplies the power needed for the backlight could have died. It's located behind the LCD bezel and is usually pretty cheap (around $10-$15 on eBay).
- If none of this helps, then it looks like there's a new motherboard in your future.