That is a really neat find. Thanks for the video.

I'm not sure how this thing is wired, but if the external monitor output is dead and you've had this on other monochrome monitors sans feed before, my guess is that the video adapter is shot. Fingers crossed it's a controller card rather than something on the motherboard itself.

Keep us posted if you find anything on the keyboard.

@King_Corduroy
Just amazing! Reminds me of the Mitac LP6613 that I found among other trash 😁 Also allInOne 😀
I think those are the best if they come with expansion ports (PCI/AGP/ISA/etc.)

Are you going to thoroughly clean it?

Oh trust me this is a million times more clean than it was when I got it, but yeah I plan on making it squeaky clean even if I can't get it all working.

I hope you're prepared for the shock of going back to text based operating systems. It can be pretty jolting after being used to using GUI's for years.

That beep is very high pitched, i feel its sort of unusual to have a computer beep in such high pitch that could be actually be considered mildly annoying. So i thought it was some sound coming out of the monitor too, but whatever. This computer looks totally cool, i hope you can restore it.
Good luck!

sliderider wrote:

I hope you're prepared for the shock of going back to text based operating systems. It can be pretty jolting after being used to using GUI's for years.

Oh I still use my PCjr all the time so my love for DOS never really waned. 🤣 I know what you mean though, GUI's are wonderful for retro computing.

Some thoughts from watching the video:

Since the screen is filled and you can see the retrace lines, then the monitor is getting Hsync and Vsync from somewhere. Use an oscilloscope to probe that suspected monitor out port.

It's not likely to be CGA, since it isn't a "PC" as such. There's a chance they adopted the monochrome standard of 18kHz horizontal, 50Hz vertical. But more likely it's something non-standard. My old HP test gear used 25kHz / 60Hz for instance.

The "beep" could be coming from the CRT's HT (the brief pause between power on and Hsync starting), see if you can find the speaker/beeper and confirm.

The beep you're hearing is definitely the monitor switching on. It starts out at 13kHz and then jumps to (and stays at) about 15kHz once h-sync comes up.

A diagnostic beep would've been much lower, 100-2000Hz or so, and I assume you would only hear that when it completes its POST procedure. Maybe it just fails to POST, possibly because there's no keyboard connected?

I'd start out checking basic things first. Try re-seating any cards and cables, and check if all supply voltages are present. See if you can find brightness/contrast controls somewhere, if these are turned all the way up/down you may not see any text either.