No visual after changing power supply

It was disconnected as I wrote this

Ok, Sorry for the dramatics, but you may be running a fire risk running this power supply. Hopefully I read your message the wrong way round, but heres my thinking ...

You have replaced a power supply with another one. You say it is of a higher voltage. Hopefully you mean power. If your power supply is normally 110 Volts and you are replacing it with one that runs on 240 volts (eg UK voltage) then there is nothing to worry about fire-wise. However, your power supply will not be able to supply enough power to run your machine. This could be your problem.

However, if you reside in a 240 Volt area and you are plugging in a 110 Volt power supply there is MAJOR cause for concern. The difference in voltage would normally blow the voltage protection circuits with a big bang and a smell of sulpher and burning. However, if this fails, then you could do irreparable damage to your computer and also make your system sun so hot it catches fire.

The same goes for laptop chargers - if you plug a 240 volt rated charger that is supposed to deliver 14 volts to your 14 volt rated laptop and you change it to a 240 volt rated charger that is supposed to deliver 20 volts then your laptop could run hot enough to catch fire.

Now thats out the way, lets assume you got things right and the next post will deal with your problem ...

Check on the motherboard and graphics card for signs of bulging capacitors. Whatever made your original power supply blow may have caused motherboard or graphics card damage.

Ensure that the power supply is connected properly. Often there are 2 connectors to the motherboard and also one to the graphics card. Make sure all is connected correctly.

If your machine has an on-board graphics card try removing yout graphics card and use the on board version. If it works there is a problem with the graphics card. It may be damaged, but it could also be badly seated. You may have displaced it when you connected the new power supply.

Try changing the graphics card. - if it has been damaged hopefully a new one will work.

Are you certain the monitor still works? Try it on another machine if possible. Also try another monitor on your machine.

Please let me know how you get on, and good luck.

Thank you for your help so far.
The monitor does work. The old power supply did have a second cord that plugged into the motherboard. This new one does not. The plug has eight....connector holes(? Forgive my lack of knowledge regarding terminology at this hour) I was told by a less experienced friend that that shouldn't affect the graphics card which is receiving power. I will check your other suggestions as well. Unfortunately I lack additional components or machines to run trial and error.