Sl compact home alarm pir's and panel dead?

Had a faulty pir in system so bought replacement, took old one down after tamper went off. Had power at first to new pir then nothing. Tried to reset at panel, but it showed all pir's were now down, which they were. Opened up keypad panel thinking there was a reset, tamper went off, then when I put panel back together the power and tamper lights were on but the board was dead. Is there an easy solution? Please help