Dead NAS and Upgrade Recommendation

I’m an amateur photographer and I have DS718+ (2x4TB - Raid 1 - so far I’m only using more or less 1TB). Sadly my DS718+ is already dead (not powering on, even after removing the drives). I already tried using another power adapter but still not powering on. Someone suggested to try changing RAM will that help?

In case there’s really no chance of fixing it I will need to buy a new one. And because it’s not a planned upgrade budget is a bit of a problem. So I was considering DS224+. Is that a good upgrade? Another one on my list would be DS423+. And I might go for a HDD upgrade as well depending on which one I’ll get.

By the way I’m located in Asia and here’s an idea on the prices that we have here.
DS224+ - 20k-21k
DS423+ - 30k-31k
DS723+ - 32k-31k
DS923+ - 39k-40k

Thank you in advance.

From what you shared with us, in particular, the amount of storage below 1TB, a 2-bay NAS is sufficient. If you do not need an SSD cache and a 10Gbit option, the DS224+ will do the job.
If you need either one or both options, go for the DS723+.

You can swap the disks to the new NAS. I do not see the need for new disks. Do you have a disk to back up your NAS?