T40 - All LEDs blink repeatedly on boot

Message

sparta.rising · #1 Post by **sparta.rising** » Tue Sep 23, 2008 9:51 pm

I just picked up a T40 with a problem that's new to me. When I power on all the LED indicators (wifi, bluetooth, numlock, capslock, hdd, z, battery, sleep, and ultrabay) blink repeatedly. Screen doesn't turn on.

I tried swapping out the RAM, removed the battery, hard drive, and optical drive.

Any ideas? I don't see the error code in the HMM.

zdriver · #2 Post by **zdriver** » Wed Sep 24, 2008 4:51 am

Sounds like a power problem, something holding down the power supply. Try unplugging the lcd display from the mainboard temporarily and see if it powers up normally.
Does the fan try to spin when the led's blink?

sparta.rising · #3 Post by **sparta.rising** » Wed Sep 24, 2008 12:05 pm

I've tried removing the LCD, unplugging the power jack and using battery power, tried both RAM slots, removing the CMOS battery and no luck with any of these. Fan does not spin up.

Any other ideas?

sparta.rising · #4 Post by **sparta.rising** » Wed Sep 24, 2008 12:10 pm

Okay, minor update, with every blink of the LEDs, the fan "twitches" like its try to start up.

sparta.rising · #5 Post by **sparta.rising** » Wed Sep 24, 2008 12:11 pm

I pulled apart the machine and took a close look at the motherboard. Nothing obviously loose, burnt, or missing. I even tried swapping the CPU with a known good one. Nada, same symptom - blink blink blink. If its a power problem, where should I be checking with a multimeter? I've tried battery and ac and both have the same problem, so its not in the connectors.

sparta.rising · #6 Post by **sparta.rising** » Sat Sep 27, 2008 11:46 am

Does anyone have any thoughts?

juhpal · #7 Post by **juhpal** » Sat Sep 27, 2008 12:23 pm

sparta.rising wrote:Okay, minor update, with every blink of the LEDs, the fan "twitches" like its try to start up.

I think that there is a short/overload somewhere in the system board. Usually this kind of blinking is called a hiccup mode in a power supply. It is a way of current limiting. The power supply tries to start, but detects a short/overload, then it turns off immediately. Then it tries to start again and same thing happens. Most likely you will need a new board unless you are an expert in finding shorts in motherboard electronics. The short may be in nortbridge/inside an IC too as happened to me (after GPU reflowing

#8 Post by **underclocker** » Sat Sep 27, 2008 12:50 pm

Try it without the fan - maybe the fan is cause an issue?

If you get the "fan error" message, just hit ESC, it will boot. You'll have about one or two minutes to check it out before the CPU reaches an unsafe operating temperature, so you should power down immediately if it boots.

sparta.rising · #9 Post by **sparta.rising** » Sat Sep 27, 2008 3:48 pm

Tried without fan before, didn't help. And it doesn't boot far enough to get error messages.

T40 - All LEDs blink repeatedly on boot

T40 - All LEDs blink repeatedly on boot

short somewhere

Who is online