My friends computers is playing up....it's a shuttle SN41G2... I'm just collected it to help. It powers up, but nothing comes on the monitor, no post screen or anything. First thought is graphics card and monitor so I swap out both for replacements. No joy. I've checked and double checked all connections, reset the CMOS too. Sometimes the power light swirls on and off, the fans speeds fluctuates. This got me thinking the power supply might be to blame. Luckily I have another PSU for these types of computer but no luck again. I'm thinking it can't be memory related because it would still post so with all those things in mind does it sounds more like CPU/MB issues?