Amplifier in protect-mode.Not the usual case and cause....

[malestrom]

I was encountering a problem,where while driving over some bumps on the road my amp would go in to protect-mode.Bear in mind this only happens with the amplifier that plays the front stage and not the sub.After 3 seconds it will play again.

While driving yesterday it went in to protect mode about 3 or 4 times (without falling in to some pit in the road) while sub kept on playing,so I went over to my friend who installed the system to see what the problem was.

Before posting this,I should say that my installation has been done by my friend which is a qualified professional.I'm posting this so as to see what everyone thinks could be the cause.

The amp in question plays my front stage which is a pair of RS Kick pro and a pair of scanspeak tweeters.No crossover .They are connected to a Mosconi A200.4 bridged mode.

Before jumping to conclusions,I'll say that everything has been double-checked and found in working condition and the problem has been found but not repaired yet. (will be during the week)

Those are:

1.speaker wires

2.RCA's

3.remote

4.ground wire

5.positive wire

6.circuit breakers

After checking all of these and leaving my system playing for half an hour or so it didn't go in to protect mode.So I decided to leave.

Well this is the fun part...I 'll give you the problem in details.Upon shifting in to 1st gear and my CD player playing a CD and letting go of the clutch a little sharply (which made the car sprint a little) the amp went in to protect mode! I did this a couple of times before calling him out.He sat in the back seat so he could see the amplifier and I did the 1st gear back and forth a couple of times and every time it would go in to protect-mode which is the red led turns to orange,on the Mosconi.

Just to be sure we checked that the CD wasn't jumping the track.So we tested it with a radio broadcast.It was OK.No protect mode.Inserting the CD,we did it again;protect-mode.Radio;OK

All this time the amp was going in to protect-mode,the sub was playing.

Clearly it is the P880 PRS which is causing the amp to go in protect mode but the question is: why does it do so,only playing a CD and not a radio broadcast and how is it possible it only makes the one amp go in to protect mode and lets the other amp (sub) keep playing?If it was the flex ribbon cable,it would do it always and not only with the CD and also to the second amp?

He didn't have time to take it out yesterday and will fix it during the week.Until he does I thought I'd post this problem just to hear your opinions and any thoughts!

Thanks

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[subzero 5,000+ posts]

CHeck your connections. ground coming loose or positive coming loose or even the remote turn could cause that. Make sure you have solide conectivity on every wire.

 

[malestrom]

Thank you for your reply.

Every possible wiring has been checked.Jumped the remote with the positive wire.Ground wire has been checked.Fuses have been checked.

As I mentioned it only goes in to protect mode while playing the CD.Wouldn't the wiring affect the radio playback also?That is the baffling problem...

It must be the head unit but why would it be so specific and cause the problem with the CD playing.Even a loose soldering would have the same result but it plays perfectly on the radio.No protect mode.

 

[subzero 5,000+ posts]

what radio? maybe the pre out voltage too high? SLA = Source Level adjustment, might be too high?

 

[TaylorFade 10+ year member]

Swap in a known good amp on the highs and see if you can replicate the problem.

 

[malestrom]

I'm sorry if I'm not making myself clear.I'll try to clarify so you have a whole picture.

My head unit is a Pioneer DEH P880prs.I have a Mosconi AS200.4 which is playing my front stage;a pair of RS Kick PRO 165 and a pair of Scanspeak tweeters (D3004/602000) without a crossover.I also have a sub,Eton 12 inch EC 12-800 which is driven by an ESX SX4120 amplifier.

I hope you have a better picture now.

what radio?

What I mean is that when the source on the head unit is CD and there's a CD playing,that's when the problem occurs.

When the source is a radio station then the problem doesn't occur.

So that's my problem.Why is it only going in to protect mode (Mosconi) when I'm listening to a CD but works flawlessly when listening to the radio? If it had to do with the wiring,ground,speakers,fuses etc the problem would occur always (when listening to the radio also)

Swap in a known good amp on the highs and see if you can replicate the problem.

It's not the amplifier.As I mentioned above,the front stage is playing excellently when listening to the radio.

 

[malestrom]

Problem solved.Thank you for the replies.

 

[TaylorFade 10+ year member]

Problem solved.Thank you for the replies.

You're not getting away that easily. What was the problem?

 

[malestrom]

You're not getting away that easily. What was the problem?

//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif
I thought so...

Well technically I might not get the right terms (regarding specific components) but I think you will get the picture.

The Premier (Pioneer) DEH-P880PRS has a switch on the left hand-side (facing it).I've uploaded a picture from the page in the manual:



My switch was set on (NW) which is for a 3 way component setup.Because I can't remember the technical terms,this is a a processor in which you can play full active.

From what my friend (installer) told me is the setting (STD) standard is where the radio signal "goes through" (!) and is basically for all other setups.

So when he changed the switch to (STD) mode,the problem was gone and that's due to the fact that the circuit for the (NW) has a problem (could be a loose soldering or something else)

That is the reason that it only did it when the CD was on and not on the radio because the functions on the (STD) are not that demanding as are on the (NW) mode.

Basically I don't run a 3 way so I don't care.On the (STD) mode my systems plays louder but with less functionality (slope,Hz,front stage etc)

I'm not going to any competitions (yet!) and my music is metal (so no sax,piano,violins etc) for me, to have a perfect SQ car,for now.I'm just relieved that I can listen to music now and eventually I will get it fixed.

I hope I answered in a way that it is understood.I'm waiting for the official "report" (with the right terms) so I can post exactly what the problem was!

Again thanks for everything!

Chris