Is my amp toast?

Last night I reinstall my subs and amp. And my amps protect lights stays on and when I hook up the subs it just makes a repeated thumping sound like a heart beat. It even does this with the rca cable out. So my question is my amp fried or is there something I can do?
400w 4 channel amp
2 10" pioneer subs

what 4 channel amp and what pioneer amp.

if its going into protect you mostlikely have something wrong in the wireing. and it is most likely not fired. but i havent blown most amp because i usually overpower my woofers in my installs. check and recheck the wireing. make sure there are no shorts or anyhting liek that.

Where are you grounding at?

What size wire?

Where is your remote wire hooked up?

how are your rcas hooked up?

How is your power wire going through the firewall?

if the ground is good, fuse is good, and the subs arent blown, or there is no shorts between the output terminals on the amp, then your amp is probably toast. Try disconnecting the subs.

Is screwing the amp on the sub-woofer box a bad idea?