Hello everyone, been lurking around here for quite some time and have now found myself in a situation where i know i could get some rock solid help here. So i will try and be as informative as i possibly can, and with that ill start with the back story.
3 years ago i bought this 05KX2500.1 from a friend, installed and ran beautifully with no problems for about a year and a half, get in my vehicle one morning, play some music at a pretty quiet level being about 8 in the morning so nothing crazy at all, went to my girlfriends place for about an hour and a half, came back out, started up my vehicle, music started playing, then a little burp came from the subs and the magic smoke pretty much filled the cab. I knew right then that it was done so i shut it off, unhooked the amp, and it's sat in the closet for the last year or so. I took it in to have it checked, and the losers said it would be 500$ to fix, and refused to tell me what it needed for parts, so i said definitely not and i've just had it here since then. I should also mention it was about -30 degrees celcius that morning, and it had only been running for about 10 minutes until i shut it off and went inside. So the idea of condesation being a culprit is very high in my mind.. but i will never know forsure.
Fast forward to now, i finally had some time to take a look at it, now i dont have much experience when it comes to inner workings of amplifiers like this, but im a mechanical engineer by trade so i do have a pretty good knowledge of electrical and i feel comfortable in being able to repair this on my own... So right now here is what i got:
I disassembled the amp, and visually i can tell i have 17/20 transistor fets blown on the left side of the amp. Both left and right rails, the other "half" of the amp looks to be in very good shape, no burn marks or anything like that. The underside of the circuit board is also perfect, no burns or cracks. From reading ive pretty much come to the conclusion i can change out all the burnt transistors but i probably have another component which caused it to burn out in the first place, so this is why i started this thread. What should be my next course of action? im gonna order the new fets on ebay (75 cents each vs 5$ the local electronics supplier wants)
ive taken as many pictures as i thought practical but if you need me to focus in on something in more detail please let me know.
http://members.shaw.ca/ignite1/1.jpg
http://members.shaw.ca/ignite1/2.jpg
http://members.shaw.ca/ignite1/3.jpg
http://members.shaw.ca/ignite1/4.jpg
http://members.shaw.ca/ignite1/5.jpg
http://members.shaw.ca/ignite1/6.jpg
http://members.shaw.ca/ignite1/7.jpg
I cut the visually blown transistors off the board, and left the 3 good looking ones still on, i realize i should take them off and test them to make sure they are still ok, but either way im going to just replace them while i do the other ones. And does anyone know that they are all the same IRF 3205, or could there maybe be a few different ones? i cant read the identifying marks on any of the burned up ones..
I look forward to being able to repair this and have my 2800 watt monster back in service, thanks everyone!
3 years ago i bought this 05KX2500.1 from a friend, installed and ran beautifully with no problems for about a year and a half, get in my vehicle one morning, play some music at a pretty quiet level being about 8 in the morning so nothing crazy at all, went to my girlfriends place for about an hour and a half, came back out, started up my vehicle, music started playing, then a little burp came from the subs and the magic smoke pretty much filled the cab. I knew right then that it was done so i shut it off, unhooked the amp, and it's sat in the closet for the last year or so. I took it in to have it checked, and the losers said it would be 500$ to fix, and refused to tell me what it needed for parts, so i said definitely not and i've just had it here since then. I should also mention it was about -30 degrees celcius that morning, and it had only been running for about 10 minutes until i shut it off and went inside. So the idea of condesation being a culprit is very high in my mind.. but i will never know forsure.
Fast forward to now, i finally had some time to take a look at it, now i dont have much experience when it comes to inner workings of amplifiers like this, but im a mechanical engineer by trade so i do have a pretty good knowledge of electrical and i feel comfortable in being able to repair this on my own... So right now here is what i got:
I disassembled the amp, and visually i can tell i have 17/20 transistor fets blown on the left side of the amp. Both left and right rails, the other "half" of the amp looks to be in very good shape, no burn marks or anything like that. The underside of the circuit board is also perfect, no burns or cracks. From reading ive pretty much come to the conclusion i can change out all the burnt transistors but i probably have another component which caused it to burn out in the first place, so this is why i started this thread. What should be my next course of action? im gonna order the new fets on ebay (75 cents each vs 5$ the local electronics supplier wants)
ive taken as many pictures as i thought practical but if you need me to focus in on something in more detail please let me know.
http://members.shaw.ca/ignite1/1.jpg
http://members.shaw.ca/ignite1/2.jpg
http://members.shaw.ca/ignite1/3.jpg
http://members.shaw.ca/ignite1/4.jpg
http://members.shaw.ca/ignite1/5.jpg
http://members.shaw.ca/ignite1/6.jpg
http://members.shaw.ca/ignite1/7.jpg
I cut the visually blown transistors off the board, and left the 3 good looking ones still on, i realize i should take them off and test them to make sure they are still ok, but either way im going to just replace them while i do the other ones. And does anyone know that they are all the same IRF 3205, or could there maybe be a few different ones? i cant read the identifying marks on any of the burned up ones..
I look forward to being able to repair this and have my 2800 watt monster back in service, thanks everyone!
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Before you order any parts . You need to check the driver transistors for the power supply fets also check the gate reistors for the power supply fets first off.
Check all gate resistors to make sure they are within tolerance. Also check the drivers for the power supply fets .
In my opinion if you have that many toasted fets i would just replace the drivers and gate resistors. Also you need to replace ALL of the power supply fets . To make this amp reliable they all need to be changed to new ones.
Also with that many fets toasted i would switch the drivers as well.
next check all of the output transistors to make sure none of them are shorted or leaking.
St your meter to ohms and check between the legs of them 1-2 1-3 2-3 you should read nothing near 0 ohms if you do post your results.
Also if you need more info Perry or carampsguru should be able to help you out .
Check all gate resistors to make sure they are within tolerance. Also check the drivers for the power supply fets .
In my opinion if you have that many toasted fets i would just replace the drivers and gate resistors. Also you need to replace ALL of the power supply fets . To make this amp reliable they all need to be changed to new ones.
Also with that many fets toasted i would switch the drivers as well.
next check all of the output transistors to make sure none of them are shorted or leaking.
St your meter to ohms and check between the legs of them 1-2 1-3 2-3 you should read nothing near 0 ohms if you do post your results.
Also if you need more info Perry or carampsguru should be able to help you out .
ok, im assuming the power supply fets are the 4 transistors (2 left 2 right) in picture one? do i have to remove them from the board for an accurate test (im thinking yes but just making sure) , are these 4 the only power supply fets? and im not quite sure which components are the "drivers"
The 3205s are the power supply FETs. The four large devices are likely rectifiers.
As was suggested previously, you need to check the output transistors. They may have failed which could have caused the power supply FETs to fail.
The remaining power supply FETs have almost certainly failed.
I'm not familiar with the power supply driver board (vertical board) but the driver transistors are likely the two transistors near the upper right corner of the driver board.
As was suggested previously, you need to check the output transistors. They may have failed which could have caused the power supply FETs to fail.
The remaining power supply FETs have almost certainly failed.
I'm not familiar with the power supply driver board (vertical board) but the driver transistors are likely the two transistors near the upper right corner of the driver board.
mine had big holes left where the mosfets once were after cleaning with lacquer thinner. http://members.shaw.ca/ignite1/vertboard.jpg
heres a closeup of the vertical board, so the 2 black.. 3 wire pieces are what i should test further? i will desolder them, and then do i just do a standard diode check with my meter?
i also found a few more transistors in the same area, i have included pictures below, let me know if these also require looking at.
http://members.shaw.ca/ignite1/relaytran.jpg
http://members.shaw.ca/ignite1/ledtran.jpg
this really pisses me off, because the place i took it to have it checked out gives me this outrageous quote, but now i realize they actually have no idea because to properly test it you have to remove the components from the circuit. which they clearly did not do at all, this makes me so glad i never decided to have them fix it. also a big lol at there "30 day guarantee" losers
Yes, the 3-legged devices on the power supply driver board are likely the power supply driver transistors. Yes, you need to remove them. When you check them, you need to confirm that both the base-collector and the base-emitter junctions are intact (~0.6v on diode check) and there is no reverse leakage.
It's not necessary to test each component to quote a price. Removing the bottom cover and testing 4-6 of the various components clamped the heatsink is enough to give an estimate. After the cover is off, it takes less than 10 seconds. The cost of the heatsink mounted components and the time it takes to replace them are the biggest factors in quoting a price. The smaller components are insignificant.
It's not necessary to test each component to quote a price. Removing the bottom cover and testing 4-6 of the various components clamped the heatsink is enough to give an estimate. After the cover is off, it takes less than 10 seconds. The cost of the heatsink mounted components and the time it takes to replace them are the biggest factors in quoting a price. The smaller components are insignificant.
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