T420 Blinking Power LED issue

[agarza]

Hi, last week my T420 refused to turn on.
After pressing the Power button, the LED around the power button blinked as if it were suspended, and so it went for about 15-20 blinks in intervals of 5 seconds each one.

I managed to make it power on again by removing the battery pressing the power button 10 times with 1 sec interval and then hold the power again for 30 seconds.
I had to use a 9 cell battery from a T430 as the normal 6 cell was not doing the trick, this was done not on the first attempt.

Again this week the same started happening, today I did a Reset battery (to the 6 cell) although the condition as shown in Power Manager is green, so I don't know if this issue is an impending motherboard failure, also I tried with another AC supply and it didn't make any difference, still no power on.

I already submitted a case for ESC (IBM Electronic Service), but so far no response it just stays there with status: EVR (EVR: IBM is validating the entitlement of your service request.)

So maybe should I give them a call, It's confussing seeing that page since it's IBM and not Lenovo's.

Any suggestions?