Is there a safe or a best practice approach when troubleshooting a preamp? I actually have an Integra DTR7.3. The preamp outputs going to my Outlaw seem to have stopped functioning.

Thanks!

M80's VP150 QS8's Earthquake SuperNova MKV-15
Integra DTR-7.4 Outlaw 755 Outlaw M200's Outlaw ICBM