On 4/1/2020 10:55 AM, VanguardLH wrote:
Bob F wrote:

My ECS Z77H2-A3 V1.2 motherboard with an I5-2500K processor worked fine
for years, then started having occasional problems when turned on, it
would not post occasionally. The problem got more frequent over months,
until it finally is next to impossible to get it to post.

When it does post, it seems to work fine, but it might take 1/2 hour of
turning the power supply on, pushing the power switch, watching it spin
the fan for 2 seconds, stopping, then powering the fan for a second,
stopping, then powering the fan for a second...... When it does
actually boot, it seems to be on the second start of the cycle.

This morning, I got it to boot, and ran it with the OCCT stress test for
40 minutes with no errors.

I then tried it with a different power supply which works fine on
another board. On the problem board, pushing the start button did
nothing. I tried jumping the green wire on the power connector to the
neighboring black wire, and that did nothing also. Unplugging the power
supply and using the jumper started it fine.

It seems to me that this is some kind of problem with the start
circuitry of the motherboard, and does not seem to affect the
processor's operation at all if it can start.

Can anyone suggest anything that might be a repair option for this kind
of problem, or point me to any references that might educate me on the
related circuitry?

The first and cheapest fix that I'd try is replaced the CMOS battery.
Afterward, clear the table in CMOS to force it to retrieve a fresh copy
from the EEPROM since what is in the table might be corrupt.

Its manual doesn't say what type of battery is used to keep power to the
RTC chip (with the CMOS table), but the mobo diagram shows a round
battery. That is likely a CR-2032 coin cell battery.


Thanks. I have checked the battery and reset the CMOS multiple time.