B450 LED Standby Behavior

[calipso99]

So i got a B450 mother with a Ryzen APU, if i turn on the power supply without the CPU installed, motherboard standby LEDs will turn on and remain on, if i do the same but with the cpu installed, motherboard stand by lights will turn on and off and then remain off.

has anyone seen that kind of behavior?

[stj]

Re: B450 LED Standby Behavior

did it ever work with that part number cpu?
these boards are a bastard because the cpu MUST be supported by the bios.

[calipso99]

Re: B450 LED Standby Behavior

Its a used board, i dont know what cpu used to run on this board, previous owner told me he hasnt touched the bios. My chip is a Ryzen 5 3400G tho. and someone has also recommended me flashing back to a previous bios

thanks for replying tho.

[calipso99]

Re: B450 LED Standby Behavior

did it ever work with that part number cpu?
these boards are a bastard because the cpu MUST be supported by the bios.

Flashing back to a bios previous to Ryzen 5000 series release didnt do anything

[stj]

Re: B450 LED Standby Behavior

i would have flashed the newest bios - not an older one.
btw, the bios writes to the syscon - you cant downgrade the syscon - i think AMD calles it AGESA.

[calipso99]

Re: B450 LED Standby Behavior

i would have flashed the newest bios - not an older one.
btw, the bios writes to the syscon - you cant downgrade the syscon - i think AMD calles it AGESA.

I flashed to newest bios before, and still wont post. all i want to know is that the board has good PCH. everything else is fixable.

[stj]

Re: B450 LED Standby Behavior

how are you flashing it?

[calipso99]

Re: B450 LED Standby Behavior

how are you flashing it?

flashback button on the back, this model has that feature. ive seen guides about it and motherboard seems to do the flashback with no issues.

[stj]

Re: B450 LED Standby Behavior

your lucky,
i have a B350 here that doesnt have that feature.
it uses a specialised flash chip so i cant even do it the hard way till my new programmer arrives from china that can flash in 4bit mode!

[calipso99]

Re: B450 LED Standby Behavior

your lucky,
i have a B350 here that doesnt have that feature.
it uses a specialised flash chip so i cant even do it the hard way till my new programmer arrives from china that can flash in 4bit mode!

I would gladly swap that flashback feature for a working motherboard or system. but... it is what it is, electronics can be so dodgy and finicky

[calipso99]

Re: B450 LED Standby Behavior

your lucky,
i have a B350 here that doesnt have that feature.
it uses a specialised flash chip so i cant even do it the hard way till my new programmer arrives from china that can flash in 4bit mode!

Being honest i forgot to mention something about the board, someone borrowed me a multimeter, which i set in continuity mode, started testing voltage rails on the power connectors to ground, got beeps on most of them. CPU side was giving me beeps, and the 24 pin was giving a lot of beeps on a lot of the pins.

[stj]

Re: B450 LED Standby Behavior

switch to resistance mode.
a beep just means 50 ohms or less - it could be a capacitor charging
that said, shorted fets wouldnt be unusual.