spill on 6 ch Jensen amp

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HeavyD'sCustom

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Joined 2009
#1
ok so i dont know if i should try and fix the two channels the were toasted.

Jensen KA 4660HLx 6ch 580 watts.


Ok my nephew borrowed this amp from me to run subs, and didnt space the amp away from the mounting surface so it over heated and shut off alot. - bad planning. or might be just trying to run too much power from this amp.

Well he brought it back, with channel 1 and 2 not working. and have pics.

but was able by unplugging the 1 and 2 channel the other 4 ch's work, still have to clean the board. but dont know if i should try to fix or just leave it a 4 channel, cause it runs the 4 channels awsome, and power.

showing burning
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showing burning
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and connectors
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#2
and more pics

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An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.


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#3
and more pics with questions


OK on most subs the is heatsink paste btween the transistors and the heat sink - this amp doesnt have any should i put some on??

and the second pic is showing two different types of hold clamps,which is better to use??
Thanx D

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.
 
#4
From what I can make out from your pictures, the only things that need insulators behind them are the 8 power supply transistors, and the 2 Rectifier diodes. The output transistors are fully encapsulated with a non conductive material. The output chip or chips on the small board also do not require an insulator.
 
#5
Is the single burnt IC the channels that don't work? That looks like an IC amp, like what a head unit has in it but hard to say how much voltage they ran to it. Can you get the number of of the IC if that is the bad channels? Those should be lower power channels I'd guess.
 
#8
I Am An Idiot said:
From what I can make out from your pictures, the only things that need insulators behind them are the 8 power supply transistors, and the 2 Rectifier diodes. The output transistors are fully encapsulated with a non conductive material. The output chip or chips on the small board also do not require an insulator.
Click to expand...

Ok for the out trans i dont need heat sink paste?
Should i have heat sink paste for the power supply transistors, and the 2 Rectifier diodes, just wondering cause every amp ive opened has this paste but not this one.
And they all have the insulator patch for all of the transisitors.

jol50 said:
Is the single burnt IC the channels that don't work? That looks like an IC amp, like what a head unit has in it but hard to say how much voltage they ran to it. Can you get the number of of the IC if that is the bad channels? Those should be lower power channels I'd guess.
Click to expand...

That could be why the ic chip burnt up, this is the two amp which is taken off easy and after taking it off the other 4 channels work fine no probs. Im going to see if i can find a # on the IC chip.


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#10
ok the IC chip is a LA4708

Features
. High power: supports total output of 30 W + 30 W
. (VCC = 13.2 V, THD = 30%, RL = 4W) Supports RL = 2W (PO = 30 W when VCC = 13.2 V,
. THD = 10%) Designed for excellent sound quality
. (fL < 10 Hz, fH = 130 kHz) . NF capacitorless . Any on time settable by external capacitor . Less pop noise . Standby switch circuit on chip (microprocessor supported) Various protectors on chip
(output-to-ground short/output-to-VCC short/
load short/overvoltage/thermal shutdown circuit)

Im going to try to find one that will handle more power
 
#12
HeavyD'sCustom said:


Im going to try to find one that will handle more power
Click to expand...

Odds are it was blown for a reason, like it was shorted or run at too low an ohm load....typically even a Jensen the amp should work fine if used at rated and proper use. If you change it you would have to find an exact replacement (pinout, capacitor settings, etc) that is likely not possible though maybe some old STK ICs are. Even then output is a function of voltage in, so it would perform the same just maybe take more abuse. I'd say use those channels for tweeters or something with no bass, or not at all. Those channels may not be bridgeable and someone could have tried it and toasted it.

Make sure sink and pads/transistors are very clean, one piece of dirt and they will not sit flat to contact the sink properly.
 
#13
id say give it a shot if you feel daring and order the chip amp from mouser or digikey. figure you'll put less than $20 into it and may get it working again.

i got a bunch of LA sound car amps that were customer returns once. they all had blown chips. it was $7 a chip to fix them.
 
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