I can't boot, and I can't enter the bios setup

[G_luca]

I have an HP pavilion P6725it (Now with windows 10). Worked perfectly for more than 5 years.

My HP has this motherboard http://support.hp.com/my-en/document/c02668523

So I bought a video card Nvidia GTX1050ti to replace the ATI HD6750 in order to work at 3840x2160 60herz.

After installing the Nvidia the system didn't boot and showed a blue screen with HP logo.

I tried to enter Bios setup but was not possible. Pressing F10 I only got a black screen with white characters indicating the processor type, the size of

the cache and the size of the ram. I just could switch off the PC.

So I reinstalled the ATI and everything was working fine again. Then I made a bios update with this

http://h20564.www2.hp.com/hpsc/swd/public/detail?swItemId=cp_101150_1

and everything was fine.

Then I entered the bios setup and I changed the setting of the Integrated video from disabled to enabled. But with this change again the system didn't boot and furthermore it was no more possible to enter the bios setup to reset the previous setting (pressing F10 just black screen with white characters ).

Then I also removed the ATI graphic card. But again, I only get the blue screen with HP logo or the black screen with white characters pressing F10.

I also tried this: http://support.hp.com/us-en/product/HP-ENVY-Phoenix-h9-1400-Desktop-PC-series/5330769/model/5349882/...

without success (black screen and white characters only)

Now what can I do to boot or enter the bios setup ?

Clearing  the CMOS setting moving the jumper can be useful ?

[redlofredlof · Accepted solution]

You know the answer already.

Clear the CMOS and you should be able to POST.

The GPU that you have installed requires a powerfull power supply.

I'd recommend a 650W power supply.

However, I do not think that the system board of your PC would support or be compatible with 3rd party power supplies.

[G_luca]

redlofredlof, thank you for your support. Clearing the CMOS allowed me to boot !!! This made me happy !

Anyway my GPU is exactly a Zotac gtx 1050 ti mini and the specification are 300 W for power supply with a power consumption of 75 W for GPU, and the power supply of my pavilion P6725it is 300 W.

https://www.zotac.com/us/product/graphics_card/zotac-geforce-gtx-1050-ti-mini#spec

This values are confirmed by measure:

http://www.guru3d.com/articles-pages/zotac-geforce-gtx-1050-ti-mini-review,8.html

So the issue for the GPU not working on my pavilion P6725it has to be something else.