MSI B350m gaming pro motherboard

[udonome]

Hi
i need help to diagnose MSI B350m gaming pro motherboard.
It does not have any display, no posting, no bios. After pressing power on, cpu fan starts and led on motherboard lights on.
All the 4 debug led for cpu, gpu, memory, boot are lighting on also.
I measured the voltages of all the choke on the board and the readings are as follows:
Choke1 = 12.080 v
Choke4 = 0.896 v
Choke5 = 0.896 v
Choke6 = 0.896 v
Choke7 = 0.895 v
Choke8 = 0.895 v
Choke9 = 1.380 v
Choke13 = 0.000 v (This seems improper)
Choke14 = 12.080 v
Choke15 = 1.078 v
I have the schematics pdf and boardview file.
Could anyone guide me how to proceed finding the faulty component please.
Thanks in advance.

[udonome]

Re: MSI B350m gaming pro motherboard

Here are the Boardview files and Schematics. MOD EDIT: Moved to new thread -> https://www.badcaps.net/forum/showthread.php?t=121256

I have also measured the all "L" on the board as follows:
L17 = 1.836v
L18 = 0.904v
L19 = 5.022v
L20 = 5.024v
L21 = 5.028v
L22 = 12.08v
L23 = 1.077v
L24 = 1.077v
L25 = 3.307v
L26 = cannot measure because it is under the headsink
L27 = 5.027v
L28 = cannot measure because it is under the headsink
L29 = 5.026v
L30 = 3.307v
L38 = 2.531v

One more noticeable irregularity is that after powering on, the power button then does not respond again if i try to power off. Neither single press, nor long press.
I have to switch off from the power supply unit.

[udonome]

Re: MSI B350m gaming pro motherboard

Update:
I dicover from the above list of "L" values compare to what is mentioned in Boardview file, it seems that "L25" which i measured as 3.307v should be 2.5v instead.
Also I noticed a scratch on the board and some weird shape solder pads. On the boardviewer file, these pads should reside a resister R611 and a capacitor C556.
I can't recall how and when this scratch happened and I am not sure if these 2 components were there in the first place.
It would be really helpful if anyone owning this same board check if these 2 components are on the board or not?
I wonder what these components serves and how much do they affect the overall function of the board.
Any advice on fixing the board would be appreciated.

[Per Hansson]

Re: MSI B350m gaming pro motherboard

Looks pretty important to me: https://cdn.badcaps-static.com/pdfs/...abd2305ab8.pdf
Values should be in the Boardview?

[udonome]

Re: MSI B350m gaming pro motherboard

In the boardviewer file, it describes pin 6 on the Linear regulator GS7133 as "PM_2P5V" so i assume it should be 2.5v constant output. And this goes to L25 which then goes into the AMD A320 chipset.

But i am totally new so i may be thinking wrong.
1. What i don't understand is why my pin 6 output is 3.3v instead of 2.5v. Is it because this linear regulator GS7133 is faulty?
OR
2. Are the missing R11 and C556 affecting the linear regulator GS7133 to not properly producing 2.5v output?

[Per Hansson]

Re: MSI B350m gaming pro motherboard

No 2 is correct, read the datasheet that I linked in my previous post, in particular related to feedback (pin 7)

[udonome]

Re: MSI B350m gaming pro motherboard

oh i see, i missed the pin 7 feedback part.
could u suggest where could i order these missing components online?

[udonome]

Re: MSI B350m gaming pro motherboard

No 2 is correct, read the datasheet that I linked in my previous post, in particular related to feedback (pin 7)

I found an old board in storage Asrock G41C-S and i am thinking of using components from this board.
I think i found the 10K resistor but i am having difficulty with the capacitor.
What does it mean "C560p50X4" ?

[SMDFlea]

Re: MSI B350m gaming pro motherboard

I found an old board in storage Asrock G41C-S and i am thinking of using components from this board.
I think i found the 10K resistor but i am having difficulty with the capacitor.
What does it mean "C560p50X4" ?

560 pico farads , 50 volt .The 4 could be the size 0402
.

[udonome]

Re: MSI B350m gaming pro motherboard

560 pico farads , 50 volt .The 4 could be the size 0402
.

Thanks a lot.
I will proceed searching for the same or similar one and will update here.