I have an issue on LA-B972 Board. Unfortunately i don't have schematic for the mboard. I checked with similar schematics but i don't have RSMRST, EC_ON on this mboard. Have +3V Ldo and +5V LDo. +3V ALW_EC on KB9012qf also available but there is no power on Bios chip pin no. 8. Does anyone having any clue.
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Last edited by raajkumar; 09-10-2020, 02:25 AM. -
Re: No EC_ON on LA-B972
on never laptops there must not be voltage 3.3ALW and 3,3V on bios, it is generated after push of start button -
Re: No EC_ON on LA-B972
I know that. SIO having EC_VCC on pins 9, 22, 33, 96, 111, 125, 67 and power switch also having +3V. But it is not producing EC_RSMRST, PBTN_OUT and EC_ON.
Does anyone having Schematic or Boardview for LA-B972 Board. I checked with LA-A992P Schematic but its not matched and totally different.Comment
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Re: No EC_ON on LA-B972
AD_ID fine?? Try changing dc jack as well . I had a similar case on LA-A994P where EC_ON was missing. Ultimately changing the dc jack helped.Comment
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Re: No EC_ON on LA-B972
I will try and let you know soonComment
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Re: No EC_ON on LA-B972
It worked but unfortunately i got 1.0Volt on bios pin no 8.Comment
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Re: No EC_ON on LA-B972
Is there any difference between KB9012QF A4 and KB9012QF A3 SIO Chips. Because this board has KB9012QF A3 SIO chip but i don't have that in stock. So i replaced with KB9012QF A4 SIO chip. Is it giving any trouble on this case?Comment
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Re: No EC_ON on LA-B972
KB9012QF-A3 and A4- i've replaced them on many mb's and have always worked. Did it on Dell LA-9981P yesterday only, original was with suffix A4 but replaced with suffix A3.Comment
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I have MSI mpg b560m bazooka motherboard . this motherboard RSMRST# signal missing . i already reprogram bios but same condition
My Motherboard this power stages are ok ...but 3vsb voltage have 4.17v (image added)
VCCRTC ok
RTCRST# ok
ATX_5VSB ok
SIO_3VA ok
3VDSW ok
DPWROK ok
SLP_SUS# ok
VSB_ENABLE# ok
5VDUAL ok
3VSB showing 4.17V
PCH_1P8_VSB ok
PCH_VCCIN_AUX ok
RSMRST# No voltage
this all voltages are ok but RSMRST# voltage is missing i did try to re program bios and change io but same... -
Lenovo Air 15ITL.
NM-D211
This laptop won't power on , when power supply is on it takes 0.001 , button trigger on it becomes after a couple of seconds 0.061 amp..and nothing
No heating (Of COURSE) , no short to GNd at all coils present , 3/5 valw is present , 3/5 vl present.
With the power plane , at state 4 +1.8VALW and +3ALW_PCH must be present but no one due to enable signal is missing .
when button trigger on , 3v dow to zero than 3v , the super io send BTN_OUT#_R to pch but no rsmrst ..0v.
i follow his line , no short .
...10-21-2025, 05:53 AM -
Hi everyone, over the past few months i have taken a deep dive into motherboard diagnostics and I love the challenge. Currently im trying to learn all about the signals that travel around the motherboard, such as frequencies, enable signals High and Low logic states etc. And i have been learning to read and using the Schematics for this board that i requested here on Badcaps forum, from a few months ago, this is such a great place for these.
I’ve been working on a GA-970A-DS3 (rev. 1.0) that does not post. This motherboard has been my main learning board. I would like share...11-23-2023, 11:02 PM -
Hi, I want to change KB9012QF A4 on bored model LA9981P for KB9012QF A3 on bored model LA-9104P can i do it without programming because it in old bored and already programmed -
First problem of the laptop was when cahrger connected Charger led is not present..
after checking all ive decided to flash the bios.
Now the DC jack glows ,after checking the first reset signal the RSMRST# IS ov
32,768KHZ is present at Y5 on oscilloscpoe
RTCRST# has 3.3v @ CLRP2
RSMRST# 0v @ pin 100 f ec
ON/OFFBTN @ pin 32 has 3.3v when triggered goes 0v and goes 3.3v if released
PWRBTN_OUT# @ 117 has 3.3v if triggered the switch doesnt goes to 0v .
EC_ON @ 102 -3.3v
Ill also attched my backup...
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