none are heating excessivly i checked through them while driving a signal of about 4v into the amp to check for heat, i didnt see any difference. Should i test through them all or start pulluing the drivers on the card and test them for leaking?
In curcuit they all seem ok, none that jump out at me.
In curcuit they all seem ok, none that jump out at me.
rhempz01, I just finished repairing a JL 450/4. After replacing all burnt power supply FETs and SMD gate resistors for CH1 and 2, I noticed the same high current draw when I testing. My power supply resets automatically when this happens. Strange thing I found is that the common anode rectifier for these channels checks short on any pin combination while on board but is good off the board. When I checked the 4 rail capacitors, I found one that is actually shorted (YEC 2200µF 85°). I replaced it and tested - the channels worked. The channel with the new capacitors (I initially changed only two to quickly check; new ones are Illinois Capacitors 2200µF 85°) sounded much louder. Everything was back to normal when I replaced all capacitors. I went ahead and replaced the caps, supply and output FETs.
Some of the opamps
Photo 1 still working on adding the voltages to the photos. The voltages on the left of the opamps are all pin 1 on the right 7 next to the corresponding component.
I did turn down the to that channel and got the temperature under control. I believe it is working properly. I will run and audio test
Photo 1 still working on adding the voltages to the photos. The voltages on the left of the opamps are all pin 1 on the right 7 next to the corresponding component.
I did turn down the to that channel and got the temperature under control. I believe it is working properly. I will run and audio test
Attachments
If I have the switch on channels 1&2 selected the bp then it seems there is a low pass filter activated, when selected to lp the amp works normally,? On all channels in either 2ch/4ch mode. I changed the switch out that made little difference. It's a snapping sound when you select the 12/24bd filter slope. It is working and sounds really good, just seems like something is not correct with that.
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