Magic 3 is not working in V3,5 or 7???

[hilly]

Hi, I have installed a Magic 3 (original not a clone) in a V3,V5 and a V7 all are exhibiting the same symptoms - intermittant booting of backups and sometimes when you have a backup running the console will freeze and you have to reset. Has anyone experienced this? Does any one have a fix - I ma usuing the wiring diags from gamegizmo.com which have come from china-magic.com. Help!!