help with my 500/1

doorman3 · 20th February 2008, 04:04 AM

i'm trying to fix my jl 500/1.........i've replaced all the irfz44n's with exact replacement.........also replaced the irf540's with irf540n as the non n's are hard to find........i replaced the 44's resistors with 47 ohmers..........irlz34n was also replaced.

help

joe

Perry Babin · 20th February 2008, 04:15 AM

What's the problem after replacing all of those parts?

doorman3 · 20th February 2008, 01:05 PM

no lights, power or anything..........before i replaced the parts i had a green light...........so i replaced the blown parts which was the 44's and resistors and after further checking i found a couple of the 540's bad and replaced those as well.........the 44's were exact replacement and the 540's were replaced with the "n " version by IR..........i checked all the solder joints and they appear to be good.....

it seems that the irf540 is obsolete.......or at least the ones by "ir".

i wonder if the fairchild IRF540A would be a better replacement?

joe

lumanauw · 20th February 2008, 01:14 PM

Once I found JL500/1 amp not working because the through-hole plating malfunctioned (upper and lower tracks not connected). There are hundreds (and tiny) through holes in this amp.
Better to work with service manual or at least a schematic to fix this kind of amp.

sdoom · 20th February 2008, 02:20 PM

I dont think the 540N will cause trouble , at least the power or protect light would be turned on.

Do you have a scope ? If so try to check the gate´s signals of the irfz44. If you dont have a scope use a multimeter in frequency mode and check the output signals of the SMPS - chip. Usually a µPC494 (TL494) or similar SMPS-chip . If you find output signals around 20 KHz or higher the chip is working and tries to power the IRFZ44 . Follow the output signals from the TL494 , usually you ´ll find some small signal transistors (usually 2SA1266, or 2SA1015) connected to the outputs. The small signal transistors drive the IRFZ44 gates .

If there ´s no output on the SMPS-chip it is probably disabled, but then the protect-LED should be lit. Please check the fuse again and make sure 12V, GND and remote signals are ok.

lumanauw · 20th February 2008, 02:24 PM

This amp has a feature of "auto turn on" when a signal is detected (turnon without 12V to the remote terminal)

sdoom · 20th February 2008, 02:53 PM

yep but it still can be powered up with the remote turn on.

Perry Babin · 20th February 2008, 05:21 PM

The parts you used shouldn't cause any problems.

Is the preamp board plugged into the amp?

Are all of the pins aligned properly?

doorman3 · 20th February 2008, 06:02 PM

yeah, the preamp board is plugged in............fuse? i don't see any kind of a fuse in this amp.......ok i found 2 through-hole plating malfunctions......one in the topside of the 44n's and one on the bottom of the 540n's............and the auto turn on is connected........i'm still checking....

all advice is welcome.
thanks
joe

Perry Babin · 20th February 2008, 06:21 PM

On the 10 pin plug near the power terminal block, post a list of the voltages on the pins. Bottom left is 1. Bottom right is 5. Top right is 6. Top left is 10.

Set the meter to DC volts. Black lead on the ground terminal of the amp.

20th February 2008, 04:04 AM	#1
doorman3 diyAudio Member Join Date: Feb 2008	help with my 500/1 i'm trying to fix my jl 500/1.........i've replaced all the irfz44n's with exact replacement.........also replaced the irf540's with irf540n as the non n's are hard to find........i replaced the 44's resistors with 47 ohmers..........irlz34n was also replaced. help joe

20th February 2008, 04:15 AM	#2
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	What's the problem after replacing all of those parts? __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

20th February 2008, 05:21 PM	#8
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	The parts you used shouldn't cause any problems. Is the preamp board plugged into the amp? Are all of the pins aligned properly? __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

20th February 2008, 06:21 PM	#10
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	On the 10 pin plug near the power terminal block, post a list of the voltages on the pins. Bottom left is 1. Bottom right is 5. Top right is 6. Top left is 10. Set the meter to DC volts. Black lead on the ground terminal of the amp. __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

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20th February 2008, 01:05 PM	#3
doorman3 diyAudio Member Join Date: Feb 2008	no lights, power or anything..........before i replaced the parts i had a green light...........so i replaced the blown parts which was the 44's and resistors and after further checking i found a couple of the 540's bad and replaced those as well.........the 44's were exact replacement and the 540's were replaced with the "n " version by IR..........i checked all the solder joints and they appear to be good..... it seems that the irf540 is obsolete.......or at least the ones by "ir". i wonder if the fairchild IRF540A would be a better replacement? joe

20th February 2008, 01:14 PM	#4
lumanauw diyAudio Moderator Emeritus Join Date: Oct 2002 Location: Bandung	Once I found JL500/1 amp not working because the through-hole plating malfunctioned (upper and lower tracks not connected). There are hundreds (and tiny) through holes in this amp. Better to work with service manual or at least a schematic to fix this kind of amp.

20th February 2008, 02:20 PM	#5
sdoom diyAudio Member Join Date: Mar 2004 Location: Heidelberg	I dont think the 540N will cause trouble , at least the power or protect light would be turned on. Do you have a scope ? If so try to check the gate´s signals of the irfz44. If you dont have a scope use a multimeter in frequency mode and check the output signals of the SMPS - chip. Usually a µPC494 (TL494) or similar SMPS-chip . If you find output signals around 20 KHz or higher the chip is working and tries to power the IRFZ44 . Follow the output signals from the TL494 , usually you ´ll find some small signal transistors (usually 2SA1266, or 2SA1015) connected to the outputs. The small signal transistors drive the IRFZ44 gates . If there ´s no output on the SMPS-chip it is probably disabled, but then the protect-LED should be lit. Please check the fuse again and make sure 12V, GND and remote signals are ok.

20th February 2008, 02:24 PM	#6
lumanauw diyAudio Moderator Emeritus Join Date: Oct 2002 Location: Bandung	This amp has a feature of "auto turn on" when a signal is detected (turnon without 12V to the remote terminal)

20th February 2008, 02:53 PM	#7
sdoom diyAudio Member Join Date: Mar 2004 Location: Heidelberg	yep but it still can be powered up with the remote turn on.

20th February 2008, 06:02 PM	#9
doorman3 diyAudio Member Join Date: Feb 2008	yeah, the preamp board is plugged in............fuse? i don't see any kind of a fuse in this amp.......ok i found 2 through-hole plating malfunctions......one in the topside of the 44n's and one on the bottom of the 540n's............and the auto turn on is connected........i'm still checking.... all advice is welcome. thanks joe

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