iMac 24 2134 play dead but will do a beep every 5 sec when ram is out

My son iMac 24” 2124 die suddenly, when unplugged for a while then plug 1 led will turn on. If pressing on power button will hear fan briefly and led will go out.

I’ve removed the 2 2gb dimm under the screen, then if I keep power button on both led turn on and will get the 1 beep every 5 second like the “no ram” condition.

If I plug back the dimm and to a power on holding the power depressed I will hear sometime the chime, then followed by a single BEEP, then it turn off, no fan, nothing all led are out.

I don’t want to necessarily invest in this machine, so would it be just the ram. Or it’s something deeper?

Thanks for any tips!