hi, so i diged at some posts, but mayby somebody can help me? i got this amplifier, now, awhile ago like 2 years ago it was dismantaled, ant put together, and the thermal pad thats supposted to keep powersuply transistors not shorting out to the case, well i guess it was not allighed properly, i powerd up the amp, played music quite silently, ant boom it was smoking, jumped out disconected, damage was done, fuses did not blow, amp did not go to prottect, just no sound, replaced the transistors, and tested amplifier at home with current limmiting power suply, amplifier is off, it draws current, when its on, draws little bit more, first 3 of 6 transistors seems to be heating up, but sometimes it heats up, others time when testing it seems good, like no sound or so on, but fets doesnt heet up, current its drawing is limited too, im thinking mayby the one, of two transformers is dead? i remember awhile ago it definantly maked some weird noises, now silent, nothing seems be heating up except powersuply transistors, and i dont want to put more current, and make them cook 80+c, dont feel like waiting another month to get them shiped.
so maby somebody have some steps i should follow, or advice?
best regards in advance.
so maby somebody have some steps i should follow, or advice?
best regards in advance.
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If you cooked them up without heatsink, it's a big chance your fets are dead.
What I always do when my power supply fets heat up, is removing the rectifiers. If your power supply fets still heat up with the rectifiers removed it's a problem in your power supply section.
If your power supply only heat up when the recitifiers are installed, it's probably a fault in the output section drawing excessive current.
What I always do when my power supply fets heat up, is removing the rectifiers. If your power supply fets still heat up with the rectifiers removed it's a problem in your power supply section.
If your power supply only heat up when the recitifiers are installed, it's probably a fault in the output section drawing excessive current.
removed rectifiers, now other 3 transistors are heating up lol, the 3 ones that were heating up before, ar cold now...
and about the transistors, i dont let them heat up more than i can barely touch. just so that they dont fail on me.
and about the transistors, i dont let them heat up more than i can barely touch. just so that they dont fail on me.
You may have bad driver components.
Did you mean, MRV-T420?
In the future, please break up the text. A blank line after every sentence isn't excessive if you can't decide where to break.
Post a good quality photo of the entire board and another of the power supply section.
Please read the entire Basic Car Amplifier Repair page (even the parts that don't interest you). This will make the process of getting your amp repaired much easier.
bcae1.com - Car Amplifier Repair Tutorial - The Basics
Did you mean, MRV-T420?
In the future, please break up the text. A blank line after every sentence isn't excessive if you can't decide where to break.
Post a good quality photo of the entire board and another of the power supply section.
Please read the entire Basic Car Amplifier Repair page (even the parts that don't interest you). This will make the process of getting your amp repaired much easier.
bcae1.com - Car Amplifier Repair Tutorial - The Basics
power suply section:
154893297-1599974966855610-7130515126514313634-n — ImgBB
155138304-462099061578022-3827589220434568236-n — ImgBB
whole board:
154608756-788458668548678-3101987039315754219-n — ImgBB
153962102-420243139035833-4793139637821268244-n — ImgBB
if you need more detailed photos of certain sections, let me know.
there is alot of smd components on the backside of the pcb, and there is 2 daughter boards for adjusting gain, filters etc, but they should be all good to my knowledge?
edit: sorry for the links, couldnt get the img feature to work properly :/ but they work good now
154893297-1599974966855610-7130515126514313634-n — ImgBB
155138304-462099061578022-3827589220434568236-n — ImgBB
whole board:
154608756-788458668548678-3101987039315754219-n — ImgBB
153962102-420243139035833-4793139637821268244-n — ImgBB
if you need more detailed photos of certain sections, let me know.
there is alot of smd components on the backside of the pcb, and there is 2 daughter boards for adjusting gain, filters etc, but they should be all good to my knowledge?
edit: sorry for the links, couldnt get the img feature to work properly :/ but they work good now
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thanks, picures are seeming to work, so im goin to leave it as is for now, just waiting maybe somebody could direct me to some steps or something.
sorry for the mistake i made, amplifier Is MRV-T420 by alpine.
right now thinking about pulling the transformers off and checking them for shorted out windings, or pulling them off to see if fets heat up without them, thats the simpler stuff i sure can check. checked the two main big caps, they are good, hold charge, not shorted or anything, right know im suspecting the drivers of psu fets? no idea how to locate them, but yeah 😕
me my self as i have done my research about how amplifiers works, and how people fix them, it makes it little easer for me, but i still lack the practise part, and general knowlege.
btw amplifier is mine, and im not doing it for any kind of profit.
regards
sorry for the mistake i made, amplifier Is MRV-T420 by alpine.
right now thinking about pulling the transformers off and checking them for shorted out windings, or pulling them off to see if fets heat up without them, thats the simpler stuff i sure can check. checked the two main big caps, they are good, hold charge, not shorted or anything, right know im suspecting the drivers of psu fets? no idea how to locate them, but yeah 😕
me my self as i have done my research about how amplifiers works, and how people fix them, it makes it little easer for me, but i still lack the practise part, and general knowlege.
btw amplifier is mine, and im not doing it for any kind of profit.
regards
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Probably killed the buffer transistors or damaged the PWM chip. Remove all the power supply FETs and check for a square wave on the first (leftmost) pin with a scope, also check the value of the gate resistors to make sure they weren't cooked.
hi, sorry to bother you guys haha
so i took a deep look searching for the gate resistors, to my surprise they were smd on back side of pcb... it was writen on them 100ohms, checked them, multimeter saw nothing, disoldered them, they just fell apart
they were def burnt, so i replaced them, and power suply fets doesnt heat up when amp is off! amp draws 0.000x something amps when remote is not attached, so i think its quite good, but when remote is attached it draws 4amps at 12v with 4ohm speaker as a "resistor" to keep things from fryng.
where should i go next? power suply fets still heating up, but im definantly nearer of this thing working! its exciting tbh haha
by the way about the scope, i doesnt own one at the moment, so i cant really check too too much.
regards in advance.
so i took a deep look searching for the gate resistors, to my surprise they were smd on back side of pcb... it was writen on them 100ohms, checked them, multimeter saw nothing, disoldered them, they just fell apart
they were def burnt, so i replaced them, and power suply fets doesnt heat up when amp is off! amp draws 0.000x something amps when remote is not attached, so i think its quite good, but when remote is attached it draws 4amps at 12v with 4ohm speaker as a "resistor" to keep things from fryng.
where should i go next? power suply fets still heating up, but im definantly nearer of this thing working! its exciting tbh haha
by the way about the scope, i doesnt own one at the moment, so i cant really check too too much.
regards in advance.
by the way adding tho this, now i can hear some white noise trought the speaker "my resistor" so there is definantly now some switching going on thats generating the noise, its
quiet but its there, im quite sure its not my powersuply swiching noise since it wasnt there before, but i might be wrong.
quiet but its there, im quite sure its not my powersuply swiching noise since it wasnt there before, but i might be wrong.