Question Compatible PSU upgrade for TG01-2xxx? And whats wrong with my current one?

[Ptrkgms]

So basically, i had a prebuilt TG01-2something for a year or two and decided to go for an upgrade. The PSU the thing came with was only 310 so I bought this 400W HP one from Amazon as HP seemingly didn't sell any fit, compatible PSUs. Got my new RAM, got my new PSU and was waiting for my RX6600 to arrive. With the old GPU the new PSU worked just fine but when I put in the last upgrade, the GPU, something weird started happening. The PSU (or at least I'm like 80 percent sure it is the culprit) starts making this randomly and subtly alternating electrical whirring/buzzing noise when the pc is under load (only with specific games, programs running or situations weirdly enough. Though they are incredibly plentiful anyway). I've decided it might be a good idea to return it and try to get a non-HP one but from what I'm reading, that is impossible? Maybe? I think? It's a bit confusing so that's why I'm here.

• What's wrong with the one I have now?
• How do PSU sizes work (as in how do I know one will fit and work, both into the case itself and slot into the backplate so all the stuff like the plug, the fan and whatnot are where they are supposed to be)?
• What should I buy or where should I look?
• Should I be able to run my pc on the old 310W one while I'm waiting for a new one to arrive as long as I somehow "performance lock" my GPU or sumn?
• What should i do in general?

I know that its a lot of questions but I would be very grateful for an answer to any of them. Thanks!

 

[--SID--]

Case, motherboard and PSU have proprietary dimensions and can't be replaced by ATX specified part without replacing all 3.

The noise is probably coilwine.

What's the modelnumber of both PSUs? I doubt the 310 has the required PCIe connector for the RX6600.