Lenovo ThinkPad T450s - No POST
Hello everyone, maybe some of you will recognize this issue or thread posted on another platform but i still want to keep trying to solve or get some valid possbile issue.
Well i have an ThinkPad T450s with motherboard NM A301 REV1.0 (i5 CPU).
So this laptop power on, but it does't show any signs of image displayed on his internal display and external VGA neither, only a full black screen appears without backlight.
When i press power on, keyboard backlight bright on and then goes of, i try to use a external USB keyboard and no CAPS and no NUM LOCK.
I reset BIOS, remove the CMOS and all batteries, remove all power sources and still the same, i reflash the BIOS with lots of available supposed worked BIOS even with Password on RT809F but without success.
I measure the AMPS consumption on DC PSU and it takes 0.550A steady...
But no ThinkPad logo and no backlight nothing... always a big black screen...
I have all Voltages on Coils of board and they resistence seems nice...
I measure some other points and test the LID Close switch and cicuit is working fine, measure RMSRST and i have 3.3V.
As well on LVDS connector i have 20V and 3.3V.
RAM stick is good and tested, Try with another good RAM stick and same thing.
Could this be an issue of CPU/PCH BGA ?
Thanks in advance for all your replies.
Well i have an ThinkPad T450s with motherboard NM A301 REV1.0 (i5 CPU).
So this laptop power on, but it does't show any signs of image displayed on his internal display and external VGA neither, only a full black screen appears without backlight.
When i press power on, keyboard backlight bright on and then goes of, i try to use a external USB keyboard and no CAPS and no NUM LOCK.
I reset BIOS, remove the CMOS and all batteries, remove all power sources and still the same, i reflash the BIOS with lots of available supposed worked BIOS even with Password on RT809F but without success.
I measure the AMPS consumption on DC PSU and it takes 0.550A steady...
But no ThinkPad logo and no backlight nothing... always a big black screen...
I have all Voltages on Coils of board and they resistence seems nice...
I measure some other points and test the LID Close switch and cicuit is working fine, measure RMSRST and i have 3.3V.
As well on LVDS connector i have 20V and 3.3V.
RAM stick is good and tested, Try with another good RAM stick and same thing.
Could this be an issue of CPU/PCH BGA ?
Thanks in advance for all your replies.
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