Hi,
The EQ slider leds / lights became very dimmed for no reason. the EQ still works great , he slider functions to modify sound still works fine for both channels.
Please find the attached pictures and service manual as well. Do you think some of the components might got weaker? like any capacitors etc? Need some help please. it's a vintage EQ which produces amazing sound and i have to fix it regardless.
Looking forward.
Mobin
The EQ slider leds / lights became very dimmed for no reason. the EQ still works great , he slider functions to modify sound still works fine for both channels.
Please find the attached pictures and service manual as well. Do you think some of the components might got weaker? like any capacitors etc? Need some help please. it's a vintage EQ which produces amazing sound and i have to fix it regardless.
Looking forward.
Mobin
Attachments
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I assume both banks of fader leds have dimmed the same ?.
Check Q18 C=20V and E=11V and low AC ripple.
If you don't have a meter then replace C35 first (for testing purpose you can just bridge it with another cap) if this cures you are good to go, but I would also replace C36, C37, C38, C39 and C40 and resolder Q19 and Q19.
Max.
Clear the slider strings where leds take the power.
My onkyo 540 has the same problem.
Are you see the led faiding when you try to adjust a pot?
My onkyo 540 has the same problem.
Are you see the led faiding when you try to adjust a pot?
How is this slider lighting business working anyhow? I somehow doubt that they would have put the actual LEDs inside the sliders (necessitating lots of sliding contacts that may need a cleaning), something with the LEDs mounted at the top or bottom and some lightpipe magic would seem far less involved. But you just never know. Investigation will have to continue inside the slider module.
hello thimios ... "Clear the slider strings?" sorry i don't understand that. the led's are not supposed to fade in or fade out when moving the slider.
Each slider bank has 7 bands, not just a single adjuster as qouted. look for pioneer SG-540 equalizer slider. a picture is already posted above.
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I have tested all the led separately and they work just fine. i have tested the all the led's to a different EQ and they light up quite well.
Yes Max, all the LED's are very dimmed that you can hardly notice. each slider bank has 7 bands, in total there are 14 for both channels.
i assume English is not his first language, what i understand what he's trying to say to clean the slider banks with some cleaning agents, wd40 or alcohoal maybe and see if it makes any difference...
I don' say that is the case, i say something like this
I see the picture, this is a custom ordered part.
PS now i see your answer that you have done a try to another unit where the pot/led combination works fine.
Look at the led power supply.
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First thing is to check voltages as I described, if there were contact issues the two banks of leds would likely be different brightnesses.
They are standard ALPS or the likes faders on a Pioneer pcb and plastic housing, all standard stuff in the eighties.
Nope just measure between ground and positive end of C35, it should be 20V DC or so as per the schematic with maybe 1V of AC ripple.
If 20V DC is low and the AC ripple is high then C35 is dead/dying and like I said just bridge it with another suitable cap to confirm.
If 20V DC is low and the AC ripple is high then C35 is dead/dying and like I said just bridge it with another suitable cap to confirm.