How to diagnose a problem when running the ubuntu installer?

Question

linux

When installing lubuntu, the battery on the laptop ran out, after which any subsequent installation hung before even starting. Those. the unetbootin menu appeared, but when choosing to run without installation / installation, it hangs when the logo is shown.
Tried lubuntu/xubuntu (all via unetbootin).
How to find the source of the problem? Perhaps he drove off during the partitioning of the disk (it was about a year ago), if so, how to check / fix it? disk check from the unetbootin menu did not reveal any errors.