Need schematic for Realistic 31-2020A graphic equalizer

[Quikfix]

screen has all LEDs on all the time. An old post indicates they had an issue with a series transistor in the negative supply, but that doesn't really help much...

If anyone knows where I can find it or post the pdf that would be great.

Thanks!

 

[KilgoreCemetery]

It's on the download list over at HiFiEngine

https://www.hifiengine.com/manual_library/realistic/stereo-frequency-equalizer.shtml

 

[73's de Edd]

Sir Quikfix . . . . .

If lightning actually has struck twice . . . . your same fix would be:
The marked in RED BOX . . . as being PNP pass transistor Q504.
BUT . . . an additionally blown R512 fusible resistor or shorted D503 Zener diode are equally being suspect.


RELEVANT SCHEMATIC SNIPPET . . . . .





73's de Edd
.....

 

[Quikfix]

It's on the download list over at HiFiEngine

https://www.hifiengine.com/manual_library/realistic/stereo-frequency-equalizer.shtml

Thanks very much! That's very helpful... it's hard to find a good (reliable, without spybots) website... looks like HIFI is not a scam/virus infested site. I was able to create an account and download the manual/schematic. I had forgotten that Realistic used to include their schematics on a bunch of their user manuals. Wish others did the same...
Thanks again.
Quikfix

 

[SciFi9000]

Sir Quikfix . . . . .

If lightning actually has struck twice . . . . your same fix would be:
The marked in RED BOX . . . as being PNP pass transistor Q504.
BUT . . . an additionally blown R512 fusible resistor or shorted D503 Zener diode are equally being suspect.


RELEVANT SCHEMATIC SNIPPET . . . . .

View attachment 39624



73's de Edd
.....

I realize that this is a 7-year-old post, but I picked up one of these today and all the display was lit up, then I saw this post so I had a look at the large transistors near the rectifier as shown in your image. When I jiggled on one of the transistors, it moved, so i flipped it over, retouched the solder, and presto... it works. Thank you for the post. Incidentally, I notice that the display is only effected by the right channel, is this normal? The left channel has absolutely no effect on the display. If I unplug the right channel (and keep the left connected), the display goes blank.

 

[SciFi9000]

screen has all LEDs on all the time. An old post indicates they had an issue with a series transistor in the negative supply, but that doesn't really help much...

If anyone knows where I can find it or post the pdf that would be great.

Thanks!

I just pick up one of these equalizers today with the exact same issue, it turned out to be one of the transistors with a dry solder joint as described by the old post you are referring to.