Problems with Panasonic CQ-C8400U

Bun-Bun
10+ year member

Senior VIP Member
Ok my GF totalled her truck a few weeks ago and I got the head unit out of it. Well now I went to put it in her 91 cavalier we just bought but no audio would come out of the built in amp. I hooked up my PG amp to the pre-outs and it works fine so I installed my amp and the head unit and got everything work just to find out the speakers in teh car were blown but thats a whole other issue that im working out as well...

The problem is you will be driving for awhile and then all of a sudden the volume will cut in half and then a few seconds later the unit shuts down (it displays the shutting down animation and goes to the clock) and will not turn back on until either 1. remove faceplate and put back on 2. shut off the car and turn back on.

Now I normally would just say screw it and go buy a new deck but she really likes this deck. The biggest thing she likes about it is you can put pictures on the display and it has a really nice display which I can't seemt o find any other (reasonably priced) units out there with this feature.

The only thing I can think of is a heatsink got shifted in the unit and its now overheating? Or does it need that power module plugged in? (the silver box with some fets in it that if you unplug the internal amp stops working so I disconnected it since im only using the pre-outs now)

Any help would be appreciated...

 
I will try that tonight... gf just phoned me and the deck is not powering up at all now but that could just be the faceplate contacts being dirty again.

What exactly does that module do? I assumed it was power for the internal amp cause whenever I forgot to plug it in the internal amp wouldn't work. But now the internal amp doesnt work at all (even with the module plugged in) so I have left it out and am just useing pre-outs...

 
Well, I dont know what happened. I hooked up that module last night and out of curiosity i tried the internal amp again ... IT WORKED!

So I have no idea why it wasn't working when I went to install it. But now everything is working perfectly fine and I have no idea why...

 
Activity
No one is currently typing a reply...
Old Thread: Please note, there have been no replies in this thread for over 3 years!
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.

About this thread

Bun-Bun

10+ year member
Senior VIP Member
Thread starter
Bun-Bun
Joined
Location
Saskatoon
Start date
Participants
Who Replied
Replies
3
Views
1,754
Last reply date
Last reply from
Bun-Bun
1778578257023.png

Glen Rodgers

    May 12, 2026
  • 0
  • 0
Screenshot_20260511_212804_Amazon Shopping.jpg

Blackout67

    May 11, 2026
  • 0
  • 0

New threads

Top