Problem with booting

You can also test your psu if you suspect no issues with your ram.

1. Obtain a known good working multimeter.
2. Open your case and before removing PSU, touch it for a few seconds to discharge any static electricity from your body.
3. Now remove psu.
4. Get a paperclip and shape it into a "U" shape. After doing this insulate the paper clip but leave about 2mm free.

4.1. Take the main plug of the psu, the 24 pin plug, and notice the green cord, this power on cord. Now plug one end of the paper clip into plug where green cord is connected and plug the other end of the paper clip into end where a black cord connects, there will be many blacks cords just choose one.

4.2 Now make sure the PSU main switch is switched off, connect it to its power cord and plug the power cord into your wall socket if its not already. Then switch on the PSU, which should power on as normal since the green and black cords are connected via the paper clip.

4.2.2. Yellow cords are 12 volts
Black cords are ground
Red cords are 5 volts
Orange cords are 3 volts +-
Blue cord on the 24 pin connector I think is -12volts (negative 12 volts)

4.2.3 Using the Multimeter

4.2.3.1 Lets take a molex connector which is used to power pcie usb 3.0 cards or high end graphics cards. Notice the molex connector should have 2 Yellow cords, 2 Red cords and 4 blacks connected to it.

Now take the blacker tester cord with the needle at the end of the multimeter and insert into a hole of the molex where a black cord is connected and take the red tester cord with needle and plug into a hole which has a yellow cord connected, at this point check the multimeter screen which should be reading 12volts+- which means it should be very close to 12volts or just over 12 volts since each psu has a 5%-+ threshold. Some models may have more so check you psu properly for allowed discrepancies.

Moving on, now if plug the red tester cord of the multimeter into a hole where a red cord is connected to the molex you should get reading on the multimeter very close to 5 volts or just over.

So we now understand that the black cord tester of the multimeter should be inserted into any place where a black cord from the psu is connected and red tester can be inserted in yellow or red power connection points.

Now test each molex connection, and those 4 holed connections used for cpu fans and I believe the cpu itself. These 4 holed connections should 2 blacks cords and 2 yellow which means these connections should supply 12 volts.

Going back to the 24 pin connector, there will be also a blue cord and grey cord. The blue i think is negative 12 volts and grey cord testing is a little different.

If you switch off the PSU, and unplug from the wall completely and remove the U shaped paper clip, now take your multimeter test grey and green together should give 5 volts which is first sign the motherboard itself uses to test if PSU is working correctly, you may need to check youtube videos how to test these green, grey and blue cords correctly as memory fails me.

NB: Please read these instructions carefully and then confirm if its correct and then decide to proceed preferably with some help and remember to insulate the U shaped paper clip properly so you do not shock yourself while testing the 24 pin plug which oddly will require re-shocking treatment from a paramedic if resuscitation fails, hopefully it will be a good looking female paramedic but then you will be unconscious so no use dreaming about that.