I have crown amp and the power went off how do i fix this issue

if it is electric window check fuse box or the window motor or the connections or switch

Changing the Battery & Alternator won't cause those issues

When people come to a site like this and say they HAD something
done & NOW have problems

You know who put them there--THE SHOP YOU WENT TO

Remove the door panel & fix the problem

When the new wiring or socket went in,
did you check for power & ground first

Sort of need that

Power supply likely failed. Electrolytics are the primary culprit.
It should have a switchmode power supply, so it is lmost likely the 5 volt section failed.

It will be the boost cap near the power switch. 220if 35v. In fact 3 caps die which kill XTi and CDi series. Amps. 2 x 220ugf and one 470 uf. All. Located yon the freuont right edge of the main PCB.

An actual crown tech

Either the speaker or the amp in it or both fried. Check to see IF your warranty will cover the repair.
Make sure that in your venues ALL interconnected equipment is powered from teh same receptacle OR power conditioner module, incling mixers, amps, speakers. Ground bounceof wiring in building power that causes damage most likely will not be covered under warranty.

Question...does the problem occur when the power amp is on only by itself ( no pre amp power ).

If it does, then because of the age of the amplifier, it could be either a capacitor, or a transistor has died. Capacitors and transistors both have age issues. Since that is a nice amplifier, I would suggest taking it to a shop because there are MANY things that can cause this condition. Subsequently, because of the age, if one component has failed, there are sure to be more to come. If you wish to keep the amp, you should consider getting it rebuilt. Hope this helps... Rob

i had to buy a complete amp and replace the old

DID YOU CHECK THE FUEL PUMP SHUTOFF SAFETY SWITCH ON THE LH/DRIVERS SIDE IN THE TRUNK & MAKE SURE IT IS DOWN ,& EVEN IF IT IS SOMETIMES YOU CAN TAKE SOMETHING & PUSH IT UP & THEN PUSH IT BACK DOWN & IT WILL CRANK,& BELOW THAT SWITCH IN THE TRUNK IS A FUEL PUMP DRIVER MODULE ,IT MAY BE BAD,THOSE ARE A COUPLE OF THINGS THAT HAVE WORKED FOR ME ,& THATS PRETTY MUCH ALL I DO IS WORK ON FORDS, & LX CROWN VICS & P71 POLICE CROWN VICS WHERE I AM WORKING, HOPE THAT IT MIGHT HELP YOU FIX IT. SEAN