Below are the beep codes. If your mac is switched to silent then the beep codes may present as flashing lights on the portable devices. !, 2 or 3 beeps are easiest to fix with replacement memory needed. 4 and 5 beeps are usually more costly with replacement hardware such as the main logic board needed. We can help you what ever the issue so please give us a call.
1 beep = no RAM installed
2 beeps = incompatible RAM types
3 beeps = no good banks
4 beeps = no good boot images in the boot ROM (and/or bad sys config block)
5 beeps = processor is not usable