As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHEN AC POWER WAS TURNED ON ALL WARNING LIGHTS OF CENTRAL WARNING PANEL ILLUMINATED AS IF WARNING LIGHT TEST SWITCH WAS ACTIVATED. A NEW ASSY WAS INSTALLED AND NO FURTHER DEFECT NOTED. PREVIOUS EXPERIENCE AN INTERNAL SHORT WAS FOUND THAT CAUSED THIS PROBLEM, THIS IS A RARE FAILURE OF THIS PART. (K)