Hello everyone.
I have a Alpine MRV-f545 that I need some help in troubleshooting a fault...
Amp works fine at low-mid volume's, However once you start going up high in volume the amplifier shuts off and displays 'CUR' which as I understand is OVER Current.
It's not a Ohm issue, amp is only hooked up to 2 4ohm alpine type r speaker's. Yet amp still goes into this protect mode(CUR)
Gain's are set appropriately.
This amp SHOULD be able to run a pair of r type's with no issues.
Speakers have been running off old 4ch amp for months with no issues, So I know it's not a speaker fault.
I have tested other speakers on the alpine amp, Does the same thing(CUR)
It is definitely a issue with the amplifier.
Wiring is all well and good, Plenty of power via 3 batterys and 2 alternator's.
ground's checked and double checked, there fine.
Even ran a new ground point, amp still faulty.
Rest of wiring has been checked and fine.
RCAs checked and fine.
Ran amp off another seperate power system, still faulty.
I purchased the amp recently from someone online who told me amp was in perfect condition....Thanx!!!!! it's faulty.
Disconnected one of my amp's just to test the new alpine before I permanently install it, And lucky I did because it came up faulty.
I opened the amp up, Everything looks fine, Amp's internals looks new, No burns, burnt smell....anything like that....
If i disconnect all speakers from amp, then turn up the volume it does not go into protect, it only fails when speakers are connected.
Im quiet good at soldering, and the actual repair stage, Just not good at the diagnosis....
Where should I start looking???, What part's should I focus on??
You're help is much appreciated!!!, I would really like to fix the amp...
I have a Alpine MRV-f545 that I need some help in troubleshooting a fault...
Amp works fine at low-mid volume's, However once you start going up high in volume the amplifier shuts off and displays 'CUR' which as I understand is OVER Current.
It's not a Ohm issue, amp is only hooked up to 2 4ohm alpine type r speaker's. Yet amp still goes into this protect mode(CUR)
Gain's are set appropriately.
This amp SHOULD be able to run a pair of r type's with no issues.
Speakers have been running off old 4ch amp for months with no issues, So I know it's not a speaker fault.
I have tested other speakers on the alpine amp, Does the same thing(CUR)
It is definitely a issue with the amplifier.
Wiring is all well and good, Plenty of power via 3 batterys and 2 alternator's.
ground's checked and double checked, there fine.
Even ran a new ground point, amp still faulty.
Rest of wiring has been checked and fine.
RCAs checked and fine.
Ran amp off another seperate power system, still faulty.
I purchased the amp recently from someone online who told me amp was in perfect condition....Thanx!!!!! it's faulty.
Disconnected one of my amp's just to test the new alpine before I permanently install it, And lucky I did because it came up faulty.
I opened the amp up, Everything looks fine, Amp's internals looks new, No burns, burnt smell....anything like that....
If i disconnect all speakers from amp, then turn up the volume it does not go into protect, it only fails when speakers are connected.
Im quiet good at soldering, and the actual repair stage, Just not good at the diagnosis....
Where should I start looking???, What part's should I focus on??
You're help is much appreciated!!!, I would really like to fix the amp...
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Does it go into protect no matter which channel has a speaker connected (all 3 other channels open)?
Lifting Q806 or D816 will defeat the over-current protection if you want to confirm that the amp is otherwise in good working order. If you try this, use a current limiter (or a 10 amp fuse) in the B+ line and have all transistors clamped tightly to the heatsink.
Ok thanx perry,
So lift either Q806 or D816(any 1 prefered?), then power it up with a 10a fuse.
What should i do then, just leave it run on the bench or in the car?
Sorry, im not all too smart with this.
Ill start pulling it apart now, these alpine amps take a wile to get apart..
So lift either Q806 or D816(any 1 prefered?), then power it up with a 10a fuse.
What should i do then, just leave it run on the bench or in the car?
Sorry, im not all too smart with this.
Ill start pulling it apart now, these alpine amps take a wile to get apart..
I don't have a preference for either component but if you destroy the diode (D816), it may be easier to find a temporary replacement locally to allow further testing.
With the over-current protection defeated, you'll check to see if it shuts down or displays CUR.
With the over-current protection defeated, you'll check to see if it shuts down or displays CUR.
Ok, will it be marked on the board? I dont have a schematic.
What diode will i buy as a replacement?, im starting to pull it apart now.
Thanx.
What diode will i buy as a replacement?, im starting to pull it apart now.
Thanx.
I found them, both q806, and d816.
I might go with removing D816, it looks a bit easier as it does not have a smd right next to where i need to deslder.
Ill let you know once i got it out, and powered the amp up..
I might go with removing D816, it looks a bit easier as it does not have a smd right next to where i need to deslder.
Ill let you know once i got it out, and powered the amp up..
Ok so i removed d816, powered it up with a 10a fuse.
No speakers or rcas connected.
Amp turned on as normal, left it on for 5 mins and it was running as norma.
What should i do from here?
Also would you know what d816 diode is, ill need to buy a replacement but can not read numbers on it.
Thanx.
No speakers or rcas connected.
Amp turned on as normal, left it on for 5 mins and it was running as norma.
What should i do from here?
Also would you know what d816 diode is, ill need to buy a replacement but can not read numbers on it.
Thanx.
Just listen for clean audio?
So while this diode is removed, go ahead and hook it up to a speaker and play audio?
Should i keep the 10A fuse in-line while testing audio? Or can that now be removed for the time being?
Thankyou.
So while this diode is removed, go ahead and hook it up to a speaker and play audio?
Should i keep the 10A fuse in-line while testing audio? Or can that now be removed for the time being?
Thankyou.
Leave the 10 amp fuse.
Unless you have a scope, the only way to determine if each channel is producing clean audio is to listen to them individually. Hopefully one channel will have a problem. If not, further troubleshooting will be required.
Unless you have a scope, the only way to determine if each channel is producing clean audio is to listen to them individually. Hopefully one channel will have a problem. If not, further troubleshooting will be required.
No, sorry i dont have a scope.
I hooked the amp up, then ran each channel on its own, listning very carefully.
Audio was clean on every channel.
I did not turn it up very loud, did not want to push it at this stage with no protection.
It goes into protect at high volume.
Thanx.
I hooked the amp up, then ran each channel on its own, listning very carefully.
Audio was clean on every channel.
I did not turn it up very loud, did not want to push it at this stage with no protection.
It goes into protect at high volume.
Thanx.
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Email me so I can send you the service manual. You'll need to check other transistors and it will be easier if you have the manual.
babin_perry@yahoo.com
babin_perry@yahoo.com
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