Does anyone know if a power supply for an old computer can be used with a new one?

Especially I have an Asus M5A97 EVO R2.0 (with AMD FX 8320) now and I want to upgrade to an Asus TUF GAMING X570-PLUS (with an AMD Ryzen 9 3900X).
In general I want to reuse all my HDD, SSD, graphic card (mouse, keyboard, joystick, whatever). Obviously I need to buy new RAM, but should I buy a new power supply, or the old one is still ok?

My first guess is wattage output and connector compatibility. If it has enough watts and the connectors work, then should be fine. There may be more to it than that but that's all I can initially think of.

the wattage is not a question, because it is almost the same (because the new 3900x is even more efficient).
The connection is a real question, I have no idea what changed (if any). This is the most annoying part, I have no any idea how can I check it.
I would like to buy a new mobo, cpu and ram, but nothing more if possible....

Yeah, maybe the connector for the motherboard power is different. I haven't built a PC in 10 years and 1 year or so ago. did my first one since - I had to use the web site "PC parts picker" to determine compatibility. That doesn't really help with older stuff though.

Hi,

Since you have the motherboard models then look up the power requirements for each. You should see the power connector needs for each one from the manufacture.
Hope this helps.
Have fun & enjoy!

1 members found this post helpful.

That's my thought too.
I got a new mobo 5 years ago and just continued using the old PSU, and later changed it for another old PSU. I have seen a few from discarded machines, the connectors always look the same and always fit the newer mobo.

From ASUS's website, the motherboard you are considering needs a power supply with an 8-pin CPU power connector, or both 8-pin and 4-pin CPU power connectors. Power supplies with only a 4-pin CPU power connector won't work (those have to be from the 2000s).
Ed

I've never had any trouble with changing power supplies. Unless the old supply is an extreme 'legacy' item the connectors will be viable.You can use adapters and splitters to adapt Molex connectors to Sata. I am a radio amateur and very 'hands on' with hardware. I've had several power supplies fail and always been able to get things working with one saved from an old machine dumped with me. The power supply is the best bit of a working old machine!

ok, thanks. I will give it a try....

Another possible problem with an old Power Supply, especially when they have been "on the shelf" for some time, are failing capacitors at the DC output. Resulting in unstable or even missing voltages. Which in turn can result in weird behaving or failing hardware.

However they can be easily detected as they tend to have a bulged top and sometimes you see some dried, black or dark yellow residu on top.

As easy as they can be detected, you can also de-solder them and replace with some new ones. Just make sure you order the correct capacity,working voltage,diameter and footprint from your preferred reseller. Also mind the polarity while replacing them, as they go *boom* when polarity is reversed. (The *boom* is slightly exaggerated, but they do "explode")