v1.0 LPC bad?

I've tried for weeks now. I just can't get my modchip to boot on my v1.0/v1.1 xbox mothboard. I have tried an X3 and Aladdin XT. I have used Pinheader method and then wired install method. None of it worked. The symptom is after the soldering and connecting everything, I press the power button; for Aladdin, I can see the orange light on the eject button first, then it turns back to green and boot the TSOP BIOS. Same symptom when I rework everything to X3. I know that I have the D0 OK because without connecting the modchip, the xbox FRAG three times. Connecting the modchip, xbox does not FRAG but it just cannot boot from the modchip. I have tried both chip on other xbox, they are working fine. What might be the problem? does anyone know?