Methods for checking motherboards or how to find a problem?

Question

Iron

Today the computer did not turn on. I decided to go by the elimination method. There are two options left that stopped working - mat. board or processor. Mat. Asus m5a97 le r2.0 board. The computer turns on, but there is no signal, the speaker is silent. The video card is working.
The question is how, without the presence of a second suitable motherboard, to check who is guilty - the percent or the mother (if at all possible)?

Answer 1

Previously, I usually recommended checking the performance of the processor in the following simple way - you unfasten the cooler and turn on the computer for a short period of time, keeping your finger on the processor. If the percent started to warm up - it works.
But most likely the mother died. Why? It has more components, more chance of failure.
By the way, what does "turn on" mean? Are the coolers spinning?

Answer 2

80% for a problem in the power supply, 20% that the motherboard is bent.
Check the power supply, or find another for the test.

Answer 3

First, look for a diagram, a service manual for the board. Here is also a video from YouTube, including on other boards with similar problems.
Next, call the tracks to make sure what goes where or if there is no circuit at all.
Connect the power and measure the voltages from the input to the processor, paying special attention to the PMIC (power controller) in order to understand where which element to look for on the Internet datasheet by marking and case type.
Attention - the multimeter must have sharp needles, otherwise there is a big risk of shorting!
Oh, so it turns on? Well, then you should rather look at the RAM, the power circuits of the video card if it is discrete, or maybe just the oxidation of the contacts in the RAM slot, if in some cases this board still “beeps”, then these cases disappear (see the beeps in the service manuals etc.)
Of course it is possible, it is much harder in a smartphone, since all the BGA chips and tracks are even more difficult to trace and the dimensions are even smaller, but it is also possible, it is still normal in laptops and PCs.

Answer 4

I bet on my mother :) Prots drove?

Answer 5

1) Visual inspection for damaged / burnt / swollen elements on the board.
Swollen capacitors are often the cause of motherboard failure.
2) Checking bridges (server/south). Carefully check with your hand at the stage of turning on the board. They get very hot when they fail.
Well, in general, an ideal option for checking the POST card. Which is not expensive, and is always useful on the farm.
Well, here's another option if there is no post card, how to use the LED to check if the BIOS is working
https://www.youtube.com/watch?v=Kejo97Nw9Zc
PS. Pay attention to BP. It might be a problem too.