So they are both 386SX, to test them you need a pair of 30 pin RAM, if instead of two you find four is better, then you need an ISA video card and an ISA controller, as a drive if you don't have an HD or an IDE adapter -Memory card, you can use old floppy disks and a reader (you can easily find the 3.5 "one).
With this you can start them and check if they are fine or possibly if they have any problems.
Obviously if you can identify them you could see if the jumpers are set correctly.
An important thing is the connection to a speaker, from here to the start you can understand from the beeps if it signals any problem.

PC@LIVE wrote on 2021-07-06, 21:01:

... you need (...) an ISA controller, as a drive if you don't have an HD or an IDE adapter -Memory card, you can use old floppy disks and a reader (you can easily find the 3.5 "one).

Can I use IDE port from a sound card? But then again I think not, because it would have to be activated during boot from the config.sys file and BIOS would have to support booting from it, right?

PC@LIVE wrote on 2021-07-06, 21:01:

An important thing is the connection to a speaker, from here to the start you can understand from the beeps if it signals any problem.

Right, I forgot about that. Thanks.

Usually the IDE port on sound cards is for CD players. And I think it can be recognized through the dos startup files, but if I'm not mistaken, the driver is needed.
At the moment I don't remember exactly, but it seems to me that there is a line in the files that loads the IDE port for it to work, after that we need to load the CD-ROM driver.
So if you want to keep it simple, I would advise you to try with the floppy drive only (as a drive), afterwards if all goes well you will have to decide what to use, if an HD or an adapter-IDE.