Working on a frustrating 820-00165 board with symptoms that are...not ideal:
1. Board powers briefly and all rails (ALL_SYS_PWRGD & VCORE included) pulse for <1 second.
2. Brief fan spin accompanies power pulse, then nothing. Fan stops, all rails after S5 drop completely (S5 rails remain present/steady), no power.
3. No shorts found; VRTC present.
4. Tried a known-good (bootable) generic BIOS and no change. I use this BIOS to test with all 00165 boards with similar symptoms, so the BIOS is good. Didn't work, so replaced original BIOS.
5. U1950 very clean, tried another to be sure, no change.
6. There was one tiny spot of liquid to U5110, so I replaced it even though all pins measured properly on the old U5110.
7. I suspected SMC at first (due to liquid to U5110), but since all my rails pulse, and my S5_PWRGD (SMC_PM_G2_EN, etc) remains when all other rails drop out, and ppbus is proper, I don't think the SMC is the culprit. Someone please correct me if I'm wrong in this assumption.
8. I did test board with battery connected, as I've seen some people claim the 00165 sometimes needs battery connected (have never, ever experienced this, but tried it anyway).
9. Since the board does not cycle (it powers for split second, then off), I'd more suspect an issue with a reset_L signal possibly, instead of a shorted rail. I'd suspect a cycling symptom if the issue was a short.
I'm out of ideas. The brief pulse gives me hope the CPU isn't dead, but I'm wondering if the PCH is bad. No liquid to VRTC area or SPI area at all. Checked typical U6100/area for any signs if damage, but nothing. Strongly leaning towards PCH on this one...but hope I'm wrong!
Any help appreciated.
1. Board powers briefly and all rails (ALL_SYS_PWRGD & VCORE included) pulse for <1 second.
2. Brief fan spin accompanies power pulse, then nothing. Fan stops, all rails after S5 drop completely (S5 rails remain present/steady), no power.
3. No shorts found; VRTC present.
4. Tried a known-good (bootable) generic BIOS and no change. I use this BIOS to test with all 00165 boards with similar symptoms, so the BIOS is good. Didn't work, so replaced original BIOS.
5. U1950 very clean, tried another to be sure, no change.
6. There was one tiny spot of liquid to U5110, so I replaced it even though all pins measured properly on the old U5110.
7. I suspected SMC at first (due to liquid to U5110), but since all my rails pulse, and my S5_PWRGD (SMC_PM_G2_EN, etc) remains when all other rails drop out, and ppbus is proper, I don't think the SMC is the culprit. Someone please correct me if I'm wrong in this assumption.
8. I did test board with battery connected, as I've seen some people claim the 00165 sometimes needs battery connected (have never, ever experienced this, but tried it anyway).
9. Since the board does not cycle (it powers for split second, then off), I'd more suspect an issue with a reset_L signal possibly, instead of a shorted rail. I'd suspect a cycling symptom if the issue was a short.
I'm out of ideas. The brief pulse gives me hope the CPU isn't dead, but I'm wondering if the PCH is bad. No liquid to VRTC area or SPI area at all. Checked typical U6100/area for any signs if damage, but nothing. Strongly leaning towards PCH on this one...but hope I'm wrong!
Any help appreciated.