m25 amplifier not working

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metterklus
Posts: 4
Joined: Mon Jan 20, 2020 11:56 am

m25 amplifier not working

Post by metterklus »

Hey, I have a bridged phoenix gold m25 amplifier, but it is barely providing any sound to the speakers connected. It has power, the light is green. No fuse seems to be broken, the amplifier has worked before.

So the problem is, there is almost no sound coming to the speakers, i put gain to max and it barely makes a difference. Now i don't know anything about amplifiers or electricity in general, so i'd really appreciate some help, as the amplifier is hooked up to all the speakers in the front, and none of them are playing loud.

As i said there is some form of power going through the amplifier, since it's lighting up. Is there any chance that there isn't enough power, and thats why the speakers are playing super low? Would it even be working at all if that was the case? How can i check?
What else can break? Since there is some sound going to the speakers? It's bridged so i'm wondering, maybe the sound coming is from the other amplifier or something, I really don't know and i'm not the one who built the system either, obviously.
I don't really know what more to say, as i said, i don't know anything about this kind of stuff. Do i need a new amplifier, or is there some form of fix?
Silverhorse
Posts: 159
Joined: Sat Aug 06, 2011 1:18 am

Re: m25 amplifier not working

Post by Silverhorse »

Hi
the amplifier worked before, after that point did you change something?
can you tell how many speakers are connected to the amp? Is it a subwoofer / full range / component set?
after a few minutes is the amp very hot?
metterklus
Posts: 4
Joined: Mon Jan 20, 2020 11:56 am

Re: m25 amplifier not working

Post by metterklus »

The car wasn't used for a long time, and after that it didn't work, the car stayed at a mechanic during that time, and i don't really know what they did with the car, but when we got it back the amplifer didn't work as it once did. The subwoofer is connected to the other amp, this one connects to a couple of smaller full range(?) speakers in the front, I think there are 4 speakers connecting to this amplifier, 2 on the left and 2 on the right side of the car (2 tweeters and 2 "normal" speakers)
And i did notice that it would become quite hot on the heatsink after using it for a long time, i figured that was normal though.
Also new problem has occurred, whenever i turn the volume up even a little, it goes in to protection mode for a while, and then after a while when i turned it back down, it starts playing low sound to the speakers again.
ttocs
the Floor Sweeping Hack with Golden Ears
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Re: m25 amplifier not working

Post by ttocs »

can you post pics of what you have?
what else can I say I am a grumpy asshole most of the time.
Silverhorse
Posts: 159
Joined: Sat Aug 06, 2011 1:18 am

Re: m25 amplifier not working

Post by Silverhorse »

when it goes in protection mode, is it the red LED or the yellow LED that is turned on?
I hope the power supply caps are changed with new ones (the two caps on the right side just under the heat sink)
Last edited by Silverhorse on Tue Jan 21, 2020 12:46 pm, edited 1 time in total.
metterklus
Posts: 4
Joined: Mon Jan 20, 2020 11:56 am

Re: m25 amplifier not working

Post by metterklus »

It's the red light, as soon as i turn the volume up the green light kinda dims down a bit and flimmers while the red light is going on and off until i turn the volume down again, and the red light dissapears. How are the caps supposed to look? I know i haven't changed them atleast. I can provide more photos tomorrow, in the meantime, i will post this dark, warped photo i took yesterday while looking at the fuse.
Attachments
I apologize for the quality due to having to compress the image a lot
I apologize for the quality due to having to compress the image a lot
Silverhorse
Posts: 159
Joined: Sat Aug 06, 2011 1:18 am

Re: m25 amplifier not working

Post by Silverhorse »

the first thing you need to do is replacing these 2 caps. If not they can burn or explode. Do not power your amp again before you haven done this.
The problem wit overload will not dissapear with changing the caps Do you know how to measure the current draw of your amp?
Attachments
AMP (1)_LI.jpg
AMP (1)_LI.jpg (867.15 KiB) Viewed 5848 times
Last edited by Silverhorse on Thu Jan 23, 2020 7:23 am, edited 1 time in total.
metterklus
Posts: 4
Joined: Mon Jan 20, 2020 11:56 am

Re: m25 amplifier not working

Post by metterklus »

What kind of caps are they? And are they soldered on or how do i replace them? Also, no i don't really know how to measure current, but is the problem too much power or not enough power?
ttocs
the Floor Sweeping Hack with Golden Ears
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Joined: Fri Dec 19, 2008 9:53 pm

Re: m25 amplifier not working

Post by ttocs »

its a bit of work to remove the board to get access to the solder joints on the bottom to desolder, remove and then solder new ones in. Its best left to a pro with the value of the amp. Have you at the lest put a volt meter on it to see what the power/ground/remote is showing?
what else can I say I am a grumpy asshole most of the time.
Silverhorse
Posts: 159
Joined: Sat Aug 06, 2011 1:18 am

Re: m25 amplifier not working

Post by Silverhorse »

on this forum everything is explained in the "how to section / capacitor replacement"
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Eric D
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Re: m25 amplifier not working

Post by Eric D »

Unless I am missing something, it looks to me like your RCA jacks are broken off the circuit board. They are supposed to stay WITH the board when you remote the top cover, not come off with it. That alone is going to cause you problems.
Got "schooled" by member shawn k on May 10th, 2011...
No longer really "in tune" with the audio industry, and probably have not been for some time.
Hands down the forum's most ignorant member...
Don't even know what Ohm's law is...
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Eric D
Short Bus Driver
Posts: 4255
Joined: Sat Dec 30, 2006 8:50 am

Re: m25 amplifier not working

Post by Eric D »

Image
Got "schooled" by member shawn k on May 10th, 2011...
No longer really "in tune" with the audio industry, and probably have not been for some time.
Hands down the forum's most ignorant member...
Don't even know what Ohm's law is...
Silverhorse
Posts: 159
Joined: Sat Aug 06, 2011 1:18 am

Re: m25 amplifier not working

Post by Silverhorse »

Holy sh**t! How is that possible?
Is that the original RCA connector? Maybe the old one was replaced and the new one was not soldered like it should?
Eric you solved the mystery, look first at the most obvious things. This means you have a lot of experience.
It reminds me on a situations I think more than 15 years ago. A client phoned me explaining that the items we installed there a few days ago were not working any more. After a few questions I asked the costumer if the wall plug was still connected. The reaction was 'do you think I'm stupid?' I jumped in my car and drove a long way to the customer. When I arrived the first thing I checked was if the plug was connected and guess what... .
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