What Is The Reason For Laptop Start Up Black Screen?

[sivasucmc]

Hello Guys,
I need a help from you for solving my laptop problem.

MY LAPTOP
Toshiba satellite A215 s4697
AMD turion mobile technology
1.6 Ghz processor
1 GB RAM
ATI Radeon X1200 Integrated graphics
Windows XP
Bought on 2007,Used monthly once/twice upto 2011(5 years) Constant usage for past two years(2012,2013)

PROBLEM
Black screen on start up (NOT ALWAYS)

THINGS I HAVE DONE BUT FAILED:
Hard Reset Many times
New 2 GB RAM Installed(Tried on both slots)
Installed New battery
Glowed Bright light on screen Nothing appears
Updated BIOS to latest version
Updated Display driver and Catalyst software to latest version

sTRANGE THINGS
Mostly Laptop display works in morning (After 8 hours of rest to laptop)
After Updating BIOS it showed improvement but deteriorated

WHAT I HAVENT DONE
Exploring /Cleaning Motherboard
Opening Display panel & Checking connectivity
Reballing GPU

Guys if you need extra details i ll give you.But please help me in solving this problem.Its really frustrating to fight with laptop to make it show the screen.
Please dont tell REPLACE THE MOTHERBOAD/REPLACE THE LAPTOP

[plowter]

Get your laptop to load up and backup your data.

What do you mean 'black screen'?
Does the Toshiba logo screen load?
Are there any error messages?
Are there any beeps? The beeps can tell you what's failed.
Can you boot up from a system disk?
Can you get into the BIOS? Is the date correct?
Do you have a recovery partition or recovery disk?

Usual problems would be:
1. overheating, so clean the vents as fender suggests.
2. dud CMOS battery, should be easy to change.
3. corrupt BIOS.

[ivor4781]

try starting in safe mode and if your screen appears as you say it sometimes does ,then try reinstall from your HDD RECOVERY back up .from back up and restore in control panel

[sivasucmc]

@fender62 thanks for your answer bro

[sivasucmc]

@plowter
When I press the power button only the panel lights,battery indicator,charger indicator,Power indicator LED works,NOTHING appears on screen
There is NO TOSHIBA LOGO
Error message comes only when during successful startup ie Error no 048/028(i dont know exactly) Previous boot failed F1 to resume F2 to setup
No beeps
As i dont see anything on screen i was not able to boot from disk or to boot in safe mode and also not able to see the BIOS
But during successful startup BIOS time is correct

[sivasucmc]

@ivor4781 When I press the power button only the panel lights,battery indicator,charger indicator,Power indicator LED works,NOTHING appears on screen .As i dont see anything on screen i was not able to boot from disk or to boot in safe mode

[sivasucmc]

Thanks everyone for your answers friend

[plowter]

No Toshiba logo suggests hardware problem.
If date and time are correct suggests CMOS battery fully charged.
If booting is inconsistent suggests overheating or power problem.
If laptop boots in morning suggests overheating.

Check your power supply. Is cable or transformer hot? Is connection secure?
Check you laptop. Is underside hotter then usual?

Put the laptop somewhere cold for twenty minutes.
Be sensible and don't let it get wet or too cold!
Does it boot up now?

If it won't boot you should be able to recover the data from the hard disk.