Admin or power up password

I have the infamous "enter admin password or power on password" on my HP Laptop Pavillion dv6.  The "system failed" code is 74285776.

I tried powering down and removing the CMOS battery and powering back up.  Still get the "enter admin or power on password" message and the system failed code is still the same.

Can you help me, PLEASE ??  My laptop is out of warranty and HP wants $192 to fix it.  Can't afford that.  I'm a 77 year old struggling mystery writer, and this mystery has me buffaloed.

Thanks

DonY