Single rank RAM module compatible with dual rank RAM module?

The following problem: I actually wanted to expand my memory because I only have 8GB of RAM on my notebook and I want to expand to 16GB. Today I bought an 8GB RAM module from the same manufacturer (Micron technology and Crucial by mircron) with 3200MT / s and tried to insert it. I have two slots for RAM 1 & 2 on my laptop. If I insert a latch in slot 1 and leave slot 2 empty, the screen stays blank when booting up. If I insert my bolt into slot 2 and leave slot 1 empty, my screen works without any problems and I have already tried that with both bolts, it works with both. If I occupy slots 1 & 2, the screen remains blank again, although slot 2 is occupied. Is it because of the slot why the screen is missing? The 8GB bar already built into my laptop is only single rank and the one I bought is dual thanks. Does that mean anything or is that the reason why it doesn't work? Or is slot 1 just defective?

First of all: no, it doesn't matter whether single-rank or dual-rank modules are mixed. They agree on the lowest common denominator with the board for operation.

If you want to operate the bars in dual-channel mode, such a mix would not make sense. Let the system fall back to single-channel (but it should still work here too).

There can always be individual incompatibilities between RAM bars that are not structurally identical. But with the same manufacturer rather unlikely.

The decision to use single or dual-ranked modules has other reasons. Dual-ranked is a little faster internally, single-ranked is thermally better suited for tight housings (less heat build-up).

According to your own tests, it doesn't matter which RAM bar is connected to slot 1, as soon as one of the two bars is in, the system no longer boots. This suggests that slot 1 has a blow. Check whether there's any contamination on the contacts or even a bent contact.