Question PC won't boot after new GPU imstalled

[Vlaedrynn]

PC won't start after installing new GPU (Details in description)

Build:

CPU: AMD Ryzen 5 3600

Mobo: Asrock B450M Pro

PSU: Thermaltake 650W

SSD: T-Force Delta 1TB

Old GPU: Radeon Sapphire RX 580

New GPU: Radeon Sapphire RX 5700 XT

Issue:
After installing new GPU, PC wouldn't boot. Lights on SSD and GPU briefly come on and immediately turn back off.

What I've tried to no affect:

Reseating RAM

Reseating GPU

Checked power and DVI connections

Where I'm at:
I removed the GPU and can now power up the PC. However, HDMI connection from mobo to monitor not working, perhaps my inboard graphics are disabled. Reset the CMOS (this is done by using a screwdriver to connect CLRCMOS pins on mobo while power is off).

Now I've tried to put my old GPU back. PC powers on but I'm not getting any video signal to my monitors.

What could be causing this? Thanks for the help.

 

[Lutfij]

Welcome to the forums, newcomer!

650W is the wattage of the PSU while Thermaltake is the brand of the unit, what is the model for the unit and how old is the PSU? Prior to dropping in the new GPU did you use DDU to remove your prior GPU's drivers? Your onboard display ports won't work since the Ryzen 5 you own doesn't have an iGPU, if you had an APU, you will get video output from the motherboard.

Might want to see if a reliably built PSU borrowed from a friend or neighbor changes your experience.

 

[Vlaedrynn]

Welcome to the forums, newcomer!

650W is the wattage of the PSU while Thermaltake is the brand of the unit, what is the model for the unit and how old is the PSU? Prior to dropping in the new GPU did you use DDU to remove your prior GPU's drivers? Your onboard display ports won't work since the Ryzen 5 you own doesn't have an iGPU, if you had an APU, you will get video output from the motherboard.

Might want to see if a reliably built PSU borrowed from a friend or neighbor changes your experience.

My PSU is a Thermaltake Toughpower GF1 650W 80+ Gold SLI. It's only a few months old.

I did not use DDU, which I was unaware of

You're right I don't have graphics on my mobo

Problem is now I can power up with my old GPU, but I'm not getting a video signal to my monitor, my CPU fan isn't starting, and my PC power will flicker and come back on every 20 sec or so, like it's trying to start