Dell Startup issues

[IT_N8]

Yeah, my mom says her dell dimension 4500s wont start up. She says that it flashes the dell screen then black then the dell screen and so on. I tried to assess her problem using the diagnostic lights on the back of the PC but she says they all flash randomly but never stay a solid color. She says if she had to guess A/D are green most of the time and B/C are yellow most of the time which i observed to be a motherboard issue.
Anyone else provide any other suggestions on what is causing this or a possible fix?

Thanks,
Nate

 

[Hefemeister]

Ask her is she is hearing any post beeps.
Reset cmos.
test ram with memtest.
reseat ram.