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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Hello, I have an asus Z97-A motherboard and it doesn't start which was working properly before, the problem isn't related by ram, ram slots or psu (I changed all and nothing work), the exact problem is when you switch it on , it starts and after 1 seconds (no boot or display picture) it's off and then on cycle continuously until you power it off from psu also it's responding to the power switch for turning it off if you keep pressing it 3 or 4 seconds (power button pin has 3.3v) , also when you start it with eatx 12v socket connected this is happening (power cycle also all voltages are resetting... -
Have a Gigabyte 2070 Super with some bonkers power draw readings. Card runs fine, other than some GPU throttling because of the power numbers. But GPU power always reads too high, more than the power reading for the entire card. And VRAM power always reads way too low, along with PCIe and 6-pin power readings. The 8-pin reading seems plausible.
Typical readout while running 720p Furmark, 8x AA:
GPU clock: 1590 MHz
Mem clock: 1750 MHz
GPU temp: 58.8 °C
Hot spot: 71.8 °C
Fan speed: 33% / 1000 rpm
Mem used: 454 MB
GPU load: 97%
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Hi all
There's two other threads about this monitor with seemingly the same problem. The problem was resolved in one case by replacing the entire PSU board and in the second one by replacing an unknown IC.
https://www.badcaps.net/forum/showthread.php?t=50657
https://www.badcaps.net/forum/showthread.php?t=40512
The first one has pictures of the pcbs and I noticed that there's one IC and assorted caps not populated on mine (but the PCB itself looks identical) so I thought that'd warrant a new thread.
It's my dad's old monitor. He... -
The sub developed a constant popping every couple seconds from woofer and power LED flickering with nothing but wall AC connected. Connecting an audio cable didn't change anything. It doesn't play but a second or two of audio in between the pops.
Opened it up and discovered the power supply is making a faint clicking or ticking sound.
I measured the amp's output to the woofer and it pulses up to 50mv DC to be driver. The pulses coincide with the power supply ticking/clicking.
I measured the power supply output going to the amp board and it too has this pulsing. Voltage cycles... -
Dear all,
I'm trying to fix an Apple A2179 (820-01958).
The laptop had water poured over it while it was on. The audio board was corroded. The VBUS pins on the connector were completely eaten away. The main board shows no signs of corrosion, but most likely was also exposed to water. Also the water corrosion on the audio board might have led to damage on the main board.
I tried first to check all pins coming from the audio board to the main board using the component tester of a Hameg HM303-6 to see if there is any damage. All looks fine. I see protection...
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