Fort the past three weeks my other computer, a Compaq Presario SR1656NX, with Windows 7 Ultimate has been having troublesome boot-ups. When I press the power button, the monitor does not display anything but black. In return, I have taken a few approaches to temporary fix it.
Wait 24 hours, checking intervals of 4 hours, to see if it will turn on. [FAILED]
Replace the cable between monitor and computer, to see if they will sync properly. [SUCCESS; however still no fix.]
Check power of the computer, check power of monitor, to see if they are receiving any. [SUCCESS; however still no fix.]
I repeat the process of turning the computer off and on, and eventually the Compaq boot-screen will display and computer boots appropriately. However, the fix does not occur. Then I did this:
System restore to a time that it did work [SUCCESS; however still no fix.]
Clean-reinstalled the Operating System. [SUCCESS; however still no fix.]
(After a windows prompt from boot success) find repairs. [SUCCESS; however still no fix.]
Upgraded RAM from 1GB to 3GB. [SUCCESS; however still no fix.]
The process of turning off and on, and waiting for "that lucky boot-up" has worked until now. The computer no longer boots, even after twenty five attempts. Please help, this is very annoying. Here are some additional notes:
I have a good second monitor, which I use for this (main) computer. It will be used on the affected (secondary) computer soon, to see if it is a monitor issue. 
The affected (secondary) computer has a poor video card, which gave a 3.0 rating for "Graphics" and a 2.5 for "Gaming Graphics" according to the Windows Experience Index (WEI) feature. Having replaced this (main) computer video card, I have a 4.7 rating Graphics and Gaming Graphics WEI card left over. It will be used on the affected (secondary) computer soon, to see if it is a video card issue. 
This should be sufficient information about the situation. If anyone has advise, opinion, or comments please post; anything is appreciated. Thank you very much!
Are you using the on-board GPU or a discrete GPU? If you are using the on-board GPU and you have access to a discrete GPU that fits, then I suggest ruling out whether the on-board GPU (you could alos do the inverse if using a discrete GPU) is defective.
Also, could be the PSU. Do you have access to another PSU that could be used to verify functionality of your current one?
You are really trying to determine if the problem is the GPU or the PSU, in my opinion here.
Currently the affected computer is using an on-board GPU (as in the video card is inside the computer, if that's what you mean.) Currently I don't have access to a replaceable PSU for the affected computer.
Definitely appreciate the advise. I'll look around online for some power supply units after I fix up this monitor (and the graphics card if the monitor experiment dosen't work out) with the affected computer.
I'll be back on sometime later tonight with results (going to procrastinate a bit on Dragon Age: Origins to keep my mind off for a little while.)
Looking forwards to your reply, and any others who have advise, opinion, or comment to add. Anything would be great!
On-board GPU refers to the video capability that is built into the motherboard, not a stand-alone card plugged into your system's PCI-E slot in the motherboard. If you have a stock Compaq, you are likely using the on-board GPU.
All you need is a PCI-E GPU (a.k.a. video card) to plug into the motherboard (everything completely powered off and disconnected from all power sources) PCI-E slot. Then connect the monitor to the discrete GPU to see what happens.
The PSU can simply be swapped from another working computer to verify functionality. Even though it is a Compaq, it uses a standard ATX PSU.
hey buddy your problem seems bigger than mine ........ i was using windows 7 for past 6 months and one day i experienced monitor screen blank ..... not a single line showed up so i tried to plug and unplug nothing worked but when i pulled out and placed ram again it started to show the monitor screen so what i did exactly i just removed RAM chip cleaned dust and placed it again properly ........... it worked for me