 | |  | |  | | CCA Hoser
Join Date: Apr 2003 Posts: 77
| i recently traded some old car parts for a kicker 400.1 amp. it doesn't work. it was checked out by previous owner and i have the estimate for 150+. says it needs main amp circuit and power supply circuit repaired, and then maybe even more. i don't feel like taking this thing in to get fixed if it's gonna cost me 200 bux and then some. i can solder, i'm pretty good with circuits and electronics, but i don't know what im looking for(don't have experience repairing, only building) so if anyonw could help me out with advice, directions, a good tech site. or even just telling me the amp isn't worth fixing, all is appreciated.
__________________ Scott<br />Winnipeg Fiero Owners Group<br /><a href="http://winnipegfieros.hopto.org" target="_blank">http://winnipegfieros.hopto.org</a> | 
|  | |   | | | | | CCA Golden Toque
Join Date: Aug 2002 Location: Kitchener, Ont Posts: 1,231
| i can help.
can u take a picture?
3 parts of an amp you need to identify
power supply
output stage
preamp
1. power supply will consists of a transformer, large caps and some transistors 4 - 8 depending on the amp.
They like to keep these together so its easy to identify.
2. output stage will consist of transistor and Big resistors conneted to one of the transistor pins.
3.Preamp. Tonnes of resisitors, caps and op amp chips. Usually near the rca inputs.. and crossovers
Can u identify these?
99% of all amp problems are the transistors.
test for shorts on any combination of pin and replace.
Sometimes when they short out they drive LOTS of current damaging the circuts on the board. So a visual inspection is always warrented.
Chris | |
| | | |   | | | | CCA Hoser
Join Date: Apr 2003 Posts: 77
| i found a little more info from the guy. they hooked up the power and ground backwards.
i am not 100% sure on identifying those 3 things however. i "think" i know where they are, but im not positive here's a pic(one with the shield on, not sure if it will help orientation or anything)   
it couldn't find anything that looked out of place. i ran power to the amp and the "protection" light comes on. so im thinking they blew something and now there's a short, does that make sense? anyway the pics are a little blurry but they were the besti could get.
thank you so much for your help.
oh also, the amp has a one year warranty on it, but only to the original owner, i dont know the original owner and i don't have a receipt, but i know where it was bought, any chance of getting it done under warranty you think?
__________________ Scott<br />Winnipeg Fiero Owners Group<br /><a href="http://winnipegfieros.hopto.org" target="_blank">http://winnipegfieros.hopto.org</a> | |
| | | | | | | | CCA Golden Toque
Join Date: Aug 2002 Location: Kitchener, Ont Posts: 1,231
| most likely its a power supply transistor
The transistor shorts out across the 3 pins.
i will try to help you identify the parts.. http://www3.sympatico.ca/chris.haig/MTX21602.JPG
there are usually same number of output transistor for each channel. Right and left
most likely on the opposite sides of the board.
Take a multi meter and measure the impedance acroos all combinations of pins on each transistor. THEY SHOULD NEVER READ 0 OHMS
YOU MIGHT GET FUNNNY READINGS AND YOU MIGHT HAVE TO REVERSE POLARITY ON THE MULTIMETER TO GET READINGS.
IF YOU READ A SHORT (O OHMS) REMOVE PART AND REPLACE. [ July 31, 2003, 02:40 PM: Message edited by: Seahag ] | |
| | | | | | | | Supporting Member
Join Date: May 2001 Location: Vancouver, B.C. Posts: 5,364
| Damn, my bro has hooked up my RF Punch 40 from '94 with the ground/power backwards, didn't burn out a thing....too bad Kicker didn't put in any reverse-polarity protection on that amp! Good luck man.
__________________
Location: Vancouver, B.C. | |
| | | | | | | | CCA Hoser
Join Date: Apr 2003 Posts: 77
| yeah, i couldn't figure it out either but it DOES have reverse polarity protection, i guess it just tells you about and then blows up. thanks for the words of encouragement anyway
that pic helped a lot. i'm pretty certain the power supply is top left, two black caps, orange/gold transformer, and four transitors(not shown in pic, they are under the silver plate). but are the two big black caps in the middle part of it too?
the output stage im a little lost on, if transitors are what i think they are, there are 13 not associated with power supply, i can't tell the difference between any of them, except some say different jibberish on them(part numbers), by big resistor do you mean size or amount of ohms? cause if i remember right the small ones are usually higher ohms.
preamp is on a separate circuit board on the right, tons of little things, lol and it's near rca/crossovers
so now i'm gonna sound really dumb, but i know what resistors look like, chips, and of course capacitors, but what do transitors look like. if they are the little black boxes with three connectors coming out of them i found them, and they all "look" alright, but how would i test them, what do i connect the multi meter too?
also, maybe getting ahead of myself, but is there anything i can do to "improve" the amp or anything i need to avoid using
also the estimate says the main amp circuit and power supply circuit need to be repaired. and then there might be more damage after that. power supply circuit is the same power supply you are talking about i assume, but then what's the main amp circuit? i'll test all the transitors tomorrow anyway.
[ August 01, 2003, 01:15 AM: Message edited by: fierce_gt ]
__________________ Scott<br />Winnipeg Fiero Owners Group<br /><a href="http://winnipegfieros.hopto.org" target="_blank">http://winnipegfieros.hopto.org</a> | |
| | | | | | | | CCA Golden Toque
Join Date: Aug 2002 Location: Kitchener, Ont Posts: 1,231
| quick not b4 i leave for the weekend.
transistors are the black boxes with three wires coming out.
To test them(because they can go bad b4 looking burnt out) take a multimeter-set it to ohms- test any combination of the 3 pins on each transisitos.
IT SHOULD NOT READ 0 OHMS.
Resistors big.. phisically big.. each output transistor will have a big resistor. and of course, there should be even numbers.
there will also be 2 transistors (really diodes but they are in the same casing as a transistor)
for the bridger rectifier.
the bridge rectifier converts AC current to DC current.
The power supply take 12v dc and boosts the voltage (via alternating current tru the transformer) then the bridge rectifier convert the ac power back to DC current.
Got to go | |
| | | | | | | | CCA Hoser
Join Date: Apr 2003 Posts: 77
| ok, thanks for all your help. i feel comfortably enough to at least replace any blown transitors now and go from there, hopefully nothing else went with them
__________________ Scott<br />Winnipeg Fiero Owners Group<br /><a href="http://winnipegfieros.hopto.org" target="_blank">http://winnipegfieros.hopto.org</a> | |
| | | | | | | | CCA Golden Toque
Join Date: Aug 2002 Location: Kitchener, Ont Posts: 1,231
| ^^ prolly not
Let us know how its going.
[img]graemlins/thumb.gif[/img] | |
| | | | | | | | CCA Golden Toque
Join Date: Aug 2001 Posts: 1,770
| if it was wired up backwards the only part ususally damaged is the diode
it is the black cylinder directly under the two capacitors beside your power connection terminals | |
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