sand blaster woes

YES frank its  a horrible freight blaster
 
When I bought it it worked very well, it's a pressurized 40 pound tank,
and now it wont keep throwing sand, if I kick it it will spurt a little
bit, but wont keep blasting. I took it completely apart and emptied it,
figuring something got stuck in there. Put new media in it, same shit,
 
Any one have any great ideas??
 
Been a long day fighting with the rascal