Ticket #10314 (assigned defect)
XO-1.5 won't boot
|Reported by:||wad||Owned by:||wad|
|Keywords:||XO-1.5, boot, solder||Cc:||rsmith, wmb@…, gary@…, beckham.chen@…, bert|
|Action Needed:||test in release||Verified:||no|
|Deployments affected:||Blocked By:|
Several XO-1.5 laptops have stopped booting. The EC boots fine, and the power light turns on when the power button is pressed, but there are no signs of CPU life: 1) the display flickers but is never turned on 2) there is no boot sound 3) there is no output on the CPU serial port.
The three units I'm currently seeing this on are:
A B2 prototype, serial number SHC93701195, received from Tiago Marques. Report from the user stated:
"My XO-1.5 B2 just entered this state last night. The only difference is that I was using it, writing e-mail, and then it rebooted itself. After that it would no longer boot so I tried to run memtest. It crashed on the second test with a random character on the right side of the screen and then it would no longer boot, the screen just flashes."
A C2 ramp laptop, serial number SHC00500908, received from George Mavrothalassitis. Report from the user stated:
"The XO was OK running OS203. I clean installed os205 with the A/C plugged in. On first boot (AC on) it froze about 4 sec. into the boot process, I _think_ at "...mass storage devices" on the console. Mic or camera lights were _not_ on. On hard reboot (with the power button for 5 sec.) the backlight blinks for a split second but the screen stays dark. The power light coms on but not the processor and wifi lights. No chime either. This remains the case for all consecutive boot-ups."
A C2 ramp laptop, serial number SHC005007AB, used at 1CC for SD card testing. One morning, it decided to stop booting. (This unit was operated without a back panel installed, and may have been damaged through ESD.)
At first glance, these motherboards seem OK. All power supplies are producing the right voltages, and power sequencing to the processor (+1.8V, VCCP, VCORE, along with CPURST and CPUPWRGD) looks OK. The clock to the processor is present and roughly correct (although it's exact frequency wasn't checked).