I can't find the power sequence in the attached schematics and I want to investigate this board because it does not power up but the white led besides the power buttonturns on when power button gets pushed.
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Re: Searching for NM-B911 power sequence
Review pg 96. -
Re: Searching for NM-B911 power sequence
I've seen that but it doesn't provide an explicit sequence?Comment
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Re: Searching for NM-B911 power sequence
No but check the voltage path flow from left to right side. Check each enable pin and respective output voltage to confirm it is present and within range of the specified value.Comment
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Re: Searching for NM-B911 power sequence
for now SYSON is not generated on pin107 of the IT8227E :-/
To me it seems to be a corrupted BIOS with the IT8227E which I never programmed (yet).Comment
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Re: Searching for NM-B911 power sequence
Remove all power -> check the resistance to ground of pin107. If the resistance is not low then yes, it may be the firmware of the noted device.Comment
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Re: Searching for NM-B911 power sequence
81K so looks fine. I cant even see a glitch or something on the scope.
So how do I read and write the bios of this board when the IT8227E contains the bios image?Comment
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Re: Searching for NM-B911 power sequence
Personally do not have the experience in such parts (yet) but it is very possible that the main bios will reflash this component so it is a bit of a catch-22 if the logic board is not booting. Wait on feedback from others.
From a brief study of this and ENE parts - the parts are often 8051 based and with SPI flash interface.Comment
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Re: Searching for NM-B911 power sequence
I programmed a few Winbond 25Q chips but not these. Indeed catch22 situation: also SIO cant read an image from USBComment
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Re: Searching for NM-B911 power sequence
just flash main biosComment
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Re: Searching for NM-B911 power sequence
I don't get a clock on the bios chip U0901 clock pin and also not on pin 105 of the KBC IT8227E.
The strange thing is that the led near the power button goes on when the powerbtn is pushed.
Is IT8227E toasted for sure or is there another way to test IT8227E kbc?Comment
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Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming... -
Hi all,
TL;DR - this laptop is driving me nuts with the oddball power-related behaviors. Appreciate any insight you can provide!
I'm experiencing a power issue on an Asus Probook P5440UF-XB74. Although I've worked with electronics and computers for decades, this is my first attempt at getting into motherboard-level component troubleshooting. Any help the community can provide is greatly appreciated!
A few weeks ago I was using the laptop (on battery power) for a Zoom meeting. The battery was running very low (long meeting) but I wasn't worried about... -
Hi all!
I'm trying to troubleshoot a Microsoft Surface Pro (5th gen) model 1796 that won't power on. Motherboard model is M1007506-015. My priority is retrieving data, but the SSD is integrated so it looks like if I can't repair it it'll need to go to a data recovery company. I've done a little basic board repair before, but nothing this advanced until now. So please forgive my ignorance in advance. 😅
I found the boardview for this laptop in the forums here, and am able to open it on my PC with FlexBV.
https://www.badcaps.net/forum/troubl...-hardware-devi... -
hi guys, my motherboard will not start no matter what
when connected to ac power, the battery does get charge, led indicator glows red when discharged and turns white as it is fully charged.
but rest nothing happens no sign of life.
this laptop has one preexisting usbc power issue - so i use DCIN jack for charging my laptop.
with this issue my laptop was unable to power ON only sometimes i just had to wait some time.
but now nothing happens no matter how much i wait/ charge/ press and hold power button.
i have no knowledge of motherboards ....10-20-2024, 02:48 PM -
I have wanting to do this project for quite sometime now and I finally found a switching power supply that will work on this desoldering gun station ZD-915 that the original switching power supply took a shit and just was not worth trying to fix it because this switching power is not quite big enough to handle the heater element and the vacuum pump
One note when I tested the switching power supply and the voltage control board I noticed that this desoldering gun heat up much faster than the original switching power supply which I was really surprised by to the point that I might buy...
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