Recently I was able to acquire a 512K compact mac. When initially powered on the system bongs and boots from the floppy, but the crt remains blank. If you wait long enough to allow the analog board to get sufficiently warm, the crt will begin working. As the temperature rises the crt will blink until it achieves a steady state. From a cold start, this process could take up to 10 minutes. Any suggestion on what to troubleshoot first?