that TPN-c126 is not the model number
In fact its the EPA/EU, power (sleep )and energystar
regulations RMN:TPN-C126 (the R means gov. regs)
if you look again at the back of pc. base.
on the right side of where you where looking
is a SERIAL.(I dont want that)
then below that, is model
"HP 255 - G5" (or very close)
when posting use real names and models
as seen here
then hp notebook PCs
behold. photo below.
one is yours, matching words on bottom of your PC.
LT black screens
below is your pc if you knew its real name.