Hi, I'm new here (first post) so sorry if I do something wrong but I've been having a ton of trouble getting this small old SBC to work over the past few months and I've tried everything I can think of to no avail. Here is a picture of the thing:

And below a diagram of the board for easy reference:

Anyways the first thing I did when I received it of course was try and power it on where I initially tried drawing via CN9 (connected through a modern ATX PSU with separate load) but then moved onto using CN20 (I did this through use of an old AT PSU by chopping up and reassembling the P8 and P9 connectors into a custom 4 pin inline connector to acquire -5V) as well. Both of these however did not work and resulted in 1 beep upon power to the board, fan spinning up, and then when the power pins are shorted just 4 short beeps and no post.

After this post code my first reaction was either the RAM had gone or the RTC module had gone so I acquired a custom RTC replacement for the specific RTC module this board had come with (a Dallas DS12C887 RTC module, credit to Necroware for the replacement design). Anyways power on PSU and SBC... Doesn't work, 4 beeps no post.

I then try RAM. I got 2 replacement sticks of DIMM and 2 sticks of SIMM. Replaced the DIMM stick twice and power on PSU and SBC... Doesn't work, 4 beeps no post.
Remove DIMM, put in 2 sticks SIMM (one was not enough and caused indefinite slow beeps and I tried with both 2 sticks configurations), and power on PSU and SBC... Doesn't work, 4 beeps no post. Below are the sticks tested:

I should note after every iteration I tried with the original RTC module and the new one along with clearing CMOS for each power on to eliminate all possibilities. After all this I decided I should mess with the jumpers and eventually just landed on leaving them in their default position. I then decided maybe it was just busted so I told the guy I got it from and he gave me another one. It is identical. I did everything again and still 4 beeps no post.

I then determine based on no information whatsoever that it must be a BIOS corruption. I was mistaken. I read the BIOS chip. Perfectly fine. I then reflashed it and... 4 beeps no post. I did the same with the other BIOS chip... 4 beeps no post. Did the same on the other board with all previous configurations... 4 beeps no post. Photo below:

Both boards also came with Millennium Modules as onboard storage solutions. I didn't bother reading what was on the modules but I tried everything above with and without a Millennium Module to no avail... 4 beeps no post. Photo below:

At the end of it all and having exhausted all solutions I could muster, I find myself begging for help. I don't know what to do to stop the 4 beeps. Please help me.