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Dear forum members, I'm sorry for not answering to threads of other members, I see that there are quicker and more experienced people than me in this forum, and I hope someone would help me.
I'm facing a problem on this machine, the owner said that he shutted down in late evening and the morning after it didn't work anymore.
The external behaviour is that you can see capslock and power button light up, then after 2 seconds capslock shutsdown, and after 4 more seconds also power led (and side led) shut down.
I detached main and cmos batteries, let the system discharge residual energy and then powered up the machine only by the adapter, the system powers up automatically and the behaviour is quite the same but only 2 seconds more.
I connected a post card (mine had 2 digits) on JDEBUG1 and it rolls out many codes until it stops for 2 seconds at 78, then displays E8 for 2 more seconds then all the main tensions shut down.
I've found no shorted or burned caps, no shorted mosfets, no smashed components, no traces of liquids (but I didn't unsolder CPU, Southbridge or KBC), I made many impedance measurements on the board, I didn't find no shorts on main inductors, the smallest values are:
+VCORE 23 Ohm
+VGFX_CORE 19 Ohm
+1.05VS 26 Ohm
Diagnostic heating on CPU SR0D2, Southbridge SLJ4K, KBC IT8572G 1202-AXS, RAM chips and other parts of the board didn't hange anything.
Following the power sequence from the M52J system, I found that after pressing the power button (or connecting the power supply without CMOS battery):
+3VA_EC 3.26
EC_RST# 3.23
+5VA 4.97
+3VSUS 3.38
+5VSUS 4.99
SUS_PWRGD 3.25
+VCC_RTC 3.20
RTCRST# 3.19
PM_RSMRST# 3.28
ME_SUSPWRDNACK 3.20
ME_AC_PRESENT 3.26
PWR_SW# 3.28 (goes to 0.03 if shorted to GND)
PM_PWRBTN# 3.26 (goes to 0.03 if PWR_SW# is shorted to GND)
+1.05VS 1.04
+0.8VS 0.88
SUSC_EC# 3.22
SUSB_EC# 3.28
PM_SUSC# 3.30
PM_SUSB# 3.31
+12VSUS 13.60
PM_SYSPWROK_PCH 3.28
PM_PWROK 3.26
SYSTEM_PWRGD 3.31
+VTT_CPU_PWRGD 3.27
ALL_SYSTEM_PWRGD 3.30 (even after E8, until complete shutdown)
CPU_VRON_PWR , linked to ALL_SYSTEM_PWRGD
VRM_PWRGD 3.27 until it comes E8 -> 0.00
PM_PWROK 3.26
H_DRAM_PWRGD 3.30 (even after E8, until complete shutdown)
H_CPU_PWRGD 3.31 (even after E8, until complete shutdown)
BUF_PLT_RST# 3.28 (even after E8, until complete shutdown)
I unsoldered BIOS chip, reprogrammed:
- same 212 version, and same ME 7.1.20.1111 rom
- same 212 version, and Clean 7.1.20.1119 ME
- new 214 version + Clean 7.1.20.1119 ME
In both cases, I had any pure ME 7.1.20.1111 from repository, so I used the next one, the 7.1.20.1119.
However, in any case, reprogramming BIOS+ME didn't cause any changes, because changin to a pure ME or an updated pure ME, it only made a longer start (maybe due to the Southbrige reading and storing the new clean ME), but after around 40 seconds, again post code E8 and system shuts down.
Since the only signal that goes down after E8 is VRM_PWRGD that goes through R5805 and becomes CORE_PWRGD, going to IT8572G, I unsoldered R5805 and observed that VRM_PWRGD initially oscillates around 1.20~2.10 then, at E8, goes strictly to 0.00, while CORE_PWRGD from KBC continues to stay up to 3.23, and RT8166B puts 4.99v on P_GFX_DL_30, effectively dischargin whatever tension is on PL8003.
At the moment I don't know if this kind of behaviour is due to bad CPU (but post codes are rolling, so I think it's ok), bad KBC (but CORE_PWRGD stays up even when VRM_PWRGD goes down), bad SouthBridge (but other startup signals come up), bad ME/BIOS, bad RT8166B (that forces VRM_PWRGD to go down) or bad SVID configuration.
I'm sorry for the long post, if you prefer I can translate in Russian language, but I can't correct it if some words are wrong...
I hope that someone can shad a light on this, thanks
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