Experts need help PLEASE MS2125

fade2blk · Post by **fade2blk** » Wed Apr 08, 2009 6:48 am

my MS2125 took a poop and lost more then half of it's power. it still comes on and still produce sound but not like it should.

ok let me explain. 1st of I am original owner of this and 3 other MS275. all of them are original untouched with sequential serial numbers except MS2125 and performed flawlessly all this years.

This amps outlived probably 7-9 vehicles that I have owned lol. Not sure what rev amps are, but They are gray from 91 or 92. they do have a sync capability for the power supplies but never used that option. and could not been happier, till today.

was driving to work and of course jamming to tunes and all of a sudden the bass started like distorting and popping sound. turned the power to radio off, and there was still popping sound for few seconds then it stopped.

stopped and looked at all the fusses and connection just to make sure. turned power back on but the sound was like halved from the MS2125.

@ work unbolted the MS2125 flipped it and took bottom plate cover off, everything seemed unharmed no traces off burnt marks and no caps are leaking... (<------ please do not flame me on capps. yes they are original, and yes I know it is a time bomb.)

all the fusses inside the amp seemed to be good and verified with DVM. Checked the voltage it is consistent 13.2. and the remote is @ 12v. The 2125 is on it's own 2 gauge wire from front to the input side. the ground is 2 gauge probably 3 ft or so.

to experts who dealt with this or came across this please shine some light.

I absolutely love this amps and do not want to replace them.

nico boom · Post by **nico boom** » Wed Apr 08, 2009 9:52 am

Welcome to the forum first of all.
You found the right place, especially when owning such amps;

As for your problem;
-have you tried wether another amp, connected to the same wires, rca's etc. produced the same sound.
-do all 4 leds come on when you power the amp up.
-does one of the clip- leds, or both light up when powered on.
-is there a chance a strand of one of the connected wires has gotten into the amp [most MS series are ruined by that]
-when connected to the battery only [no rca's, no speakercables] and powered up, howmuch voltage do you read at each speaker-connector [left, and right] DMM set at Milivolts.
-At the time you checked the fuses, was the amp HOT.
This could give us a some ideas how to help you further with this problem.
Nico

fade2blk · Post by **fade2blk** » Wed Apr 08, 2009 11:02 am

nico boom wrote:Welcome to the forum first of all.
You found the right place, especially when owning such amps;

Thank you.
to be honest I have been a long time readder onthis board and the original for quite some time. just was not a member. by reading this forum for so long, I feel like I know a lot of users here.

As for your problem;
-have you tried wether another amp, connected to the same wires, rca's etc. produced the same sound.

No I have not, I guess I can throw a ms275 on it, and see how that sounds.

-do all 4 leds come on when you power the amp up.

No they do not. the only led that comes on is a green power led.

-does one of the clip- leds, or both light up when powered on.

No the only led that comes on is power.

-is there a chance a strand of one of the connected wires has gotten into the amp [most MS series are ruined by that]

very possible, when I had the cover off I did not see anything unusual, but I will take a look at it once again, once home.

-when connected to the battery only [no rca's, no speakercables] and powered up, howmuch voltage do you read at each speaker-connector [left, and right] DMM set at Milivolts.

I borrowed a dvm earlier, and can not get my hands on one right now, will have to wait till I will get home. I will post the readings.

-At the time you checked the fuses, was the amp HOT.
This could give us a some ideas how to help you further with this problem.
Nico

the amp was not hot but was warm to the touch..... through all the years that I owned it, I can only recall that it shud down a couple of times. and both of those times during Texas summer heat.

thanks for the questions I will try to answer the ones I have missed.

nico boom · Post by **nico boom** » Wed Apr 08, 2009 11:16 am

With the 4 red led's inside NOT lighting up, you can skip the reading with the DMM....
Go look for [very small] strand[s] inside the amp; these amps do not fail suddenly for a habit; they're considered to be one of the most durable amps PG ever produced. [that's one of the things they are still very sought after].
LUK how it goes.

fade2blk · Post by **fade2blk** » Wed Apr 08, 2009 12:55 pm

I agree with you. regarding "one of the most durable amps PG ever produced."

the only thing I regred is not bying more when I had a chance. I wished I would have bought a couple of ms1000 and frank'stein...... and only got 4..guess better 4 then none.

Thanks again. I will look at it very carefully for anything that does not belong there and clean it.

fade2blk · Post by **fade2blk** » Thu Apr 09, 2009 7:03 am

ok here is what I did.

took the amp out. openned it up. flipped it over and used compressed air from the can http://www.pcuniverse.com/Belkin-Blaste ... d/p2111296 this is what it looks like. there was nothing major that came out of it. did not even see any kind of particals or strands.

once that was done put everything back together. except the remote wire.

started the car and turned stereo back on.

the other amps came on fine but once i applied the remote wire the red light next to the power on light came on for a split second then the green power light came on while the red light turned off. this was instant.

the amp functions but the actual power is still not there. did not check for any voltages since you sugested that was not needed.

any other advice?
I will also be changing all the caps on this one and the other 3. hopefully this one will get sorted with the cap change. I sure hope so.

Post by **stipud** » Thu Apr 09, 2009 7:29 am

The red LEDs he was talking about are INSIDE the amp. If you have a plexiglass base, you should see them... otherwise you will have to take off the bottom and have a look while it is running.

dBincognito · Post by **dBincognito** » Thu Apr 09, 2009 7:33 am

fade2blk

Not sure what rev amps are

Look between the rails on the board....usually near the Phoenix Gold logo that is on the board

fade2blk · Post by **fade2blk** » Thu Apr 09, 2009 8:21 am

thanks guys,

took the bottom off once again, turned the anp on and the 4 red led are on. I have never ever payed any attention to them. are they supposed to be on? or are they on if there is a problem with the amp?
sorry about such bad pic quality.

[/img]

dBincognito · Post by **dBincognito** » Thu Apr 09, 2009 8:23 am

If they are all on that is a good thing

dBincognito · Post by **dBincognito** » Thu Apr 09, 2009 8:24 am

Have we also skipped the possibility of a bad line driver ?

Do you use 1 ?

fade2blk · Post by **fade2blk** » Thu Apr 09, 2009 8:30 am

ok then why is the power not like it was. it sounds like the power was cut in half. half as loud. tonight I am gonna replace that with ms275 or one of the ppi's i have from another left over system and see how that goes.

sorry to rant but
I want my phoenix gold power back.......

dBincognito · Post by **dBincognito** » Thu Apr 09, 2009 8:31 am

Have you checked the solder connection going to the RCA's ?

Take pics of the whole board please...it will help

fade2blk · Post by **fade2blk** » Thu Apr 09, 2009 8:44 am

I do not use line drivers or loc. it is connected straight into the head unit. was working fine till yesterday morning......

radio - front = ms275 =mbquart qes series old school
radio - rear = ms275 =mbquart qes series old school
radio - sub = ms2175 = 1 ppi dcx104

fade2blk · Post by **fade2blk** » Thu Apr 09, 2009 8:51 am

dBincognito wrote:Have you checked the solder connection going to the RCA's ?

yes and no. @ the amp I have checked it and seems to be ok. did not put a metter on it as of yet. on the head unit easier said then done. a whole project b y itself. this is in 06 Acura TL with nav model. very painfull to get too.

Take pics of the whole board please...it will help[/quote]

I will try to take a better picture of the whole board.

dBincognito · Post by **dBincognito** » Thu Apr 09, 2009 8:53 am

I was concerned about the lead inside the amp going to the RCA's....also another common problem with the older MS series

If you say it is good then we will have to look elsewhere

Really need to drop another amp in the same place to see if you have the same problem

fade2blk · Post by **fade2blk** » Thu Apr 09, 2009 10:22 am

oh no I meant the RCA'S that connect to the amp from the head unit. I will look at all connections inside and out of the amp, and will try another amp as well and see how that will do.

thanks again for all the knowledge. much appreciated.

fade2blk · Post by **fade2blk** » Fri Apr 10, 2009 5:58 am

Last night, I took my sick baby out of the car. replaced it with a crunch ground pounder PZI1000.1 - 1000 Watt Digital Mono Block Power Amp. yeah what ever... if this is a ground pounder then my ms2125 is earth shaker I mean come on this is supposed to be a 1000 watt amp right? but then I relized that the only way it putts that much power @ 1 ohm. I have not ran anything that low since early 90's and ms2125 did a fraking awesome job. any way enought of rant.

the bass is better, but I can not really tell do to inferior product. not that the amp I am using is bad it just does not have the "balls" ok nicely put the headroom as the phoenix.

so the moral of the story.

my baby is sick. I took it partially apart and did notice some discolartion on the board where rail caps are. after reading all the threads and going back to soundbuggy forum those do need to be replaced.

now comes a question where to by replacements caps?
http://search.digikey.com/scripts/DkSea ... 93-1804-ND
http://search.digikey.com/scripts/DkSea ... =P11210-ND
http://search.digikey.com/scripts/DkSea ... e=P6667-ND
or
http://search.digikey.com/scripts/DkSea ... e=P6669-ND
and what about the sil-pads? where does one get those?according to this
http://parts.digikey.com/1/parts-kws/sil-pad they are none stock items. so where do you guys get them?
I have read here in several diffrent posts that Nico has them?
also should there be a heat sink compund on the chassis?

thanks again for all the help.

dBincognito · Post by **dBincognito** » Fri Apr 10, 2009 6:05 am

you can buy everything from Digi-Key...you don't need a account to make a order

Nico can also get you the whole set, sil pads, caps..the works

dBincognito · Post by **dBincognito** » Fri Apr 10, 2009 6:07 am

Use the Live Chat option on Digi-Key...it's free...24 hours a day.....and they LOVE to help you

fade2blk · Post by **fade2blk** » Fri Apr 10, 2009 6:23 am

thanks dBincognito.

I am just curious if the amp will come up to full power after the cap change. also should there be any type of Heat Sink Compound?
thanks.

dBincognito · Post by **dBincognito** » Fri Apr 10, 2009 6:34 am

I use Artic Alumina Ceramic Thermal Compound

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0140854458

Yes, you should regain full power as long as no other components were damaged, be sure to inspect the board carefully.....I use a LED flashlight to inspect the board

Post by **stipud** » Fri Apr 10, 2009 10:27 am

Digikey gave pnyrd the wrong parts, because he told them all of the specs off the cap. The problem was they gave him the same factory capacitance, but the wrong size. Since cap tech has improved over the years, you now get much more capacitance out of the same size. So when he told them the capacitance instead of size, the caps they gave him were much smaller.

The capacitors you linked for the rail caps are 35v... these are for the MPS2500 and MS275. If I recall correctly, your MS2125 has 50v caps (please check and confirm).

So you need to search digikey for
- Electrolytic capacitor
- 35.00mm x 35.00mm
- 105*C rated (ctrl-click on all the 105*C or higher ratings)
- 50 volts

Which leads to one in-stock result (the rest you have to order in bulk). 8200uF at 50v:
http://search.digikey.com/scripts/DkSea ... e=P6689-ND

As for the input caps, I recommend either of these:
http://search.digikey.com/scripts/DkSea ... 93-1804-ND
http://search.digikey.com/scripts/DkSea ... 93-1543-ND

Sil-pad replacement is a very good idea. I am not sure what size needs to be ordered, but Nico should know. You won't need to use thermal compound with them, but I suppose it can't really hurt either.

Though a bit of discoloration around the caps is usually normal, and I don't think failing caps would reduce the output of the amp substantially (though considering the age, you really should change them in ALL your amps). That is more likely a transistor issue, or something similar. I am no amp tech though, so I have no clue what it could be. Have you considered PG's flat rate repair?

Are you even sure it's the amplifier? If your gains were bumped down, or the line voltage from the headunit dropped, or a crossover somewhere was toggled... anything in your system could also drop the output of your amp.

dBincognito · Post by **dBincognito** » Fri Apr 10, 2009 10:38 am

stipud

You won't need to use thermal compound with them, but I suppose it can't really hurt either.

If he is replacing the caps he will be removing the board, anytime the board is removed the thermal compound should be removed and replaced....IMO