Pioneer SCU 2556 ZRN User manual

Enable TAPE input, Pioneer SCU 2556 ZRN:
Tape input on unit SCU2556 is disabled by firmware until the original tape-deck is connected.
This document describes how to permanently remove this function, leaving the input
functioning for mp3-players and such.
Remove amplituner from vehicle. Place it upsidedown and remove lid. (Use slotted
screwdriver and pry it open.)
Caution! Take proper action to prevent static dischare from ”killing”the electronics. Avoid
wearing fleece or wool clothing. Discharge your body by touching any grounded object –like
the kitchen sink…
The following steps require basic electronics know-how and solderingskills.
Locate doublediode D404. Carefully cut copper track as shown(use knife), or remove diode
completely.
Cut track here, and the processor is
no longer able to mute TAPE-
input.
Doing this, leaves TAPE-input always active, even when playing CD or radio. To manually
mute it, connect 12v to pin 7 of the TAPE input connector. Connect the 12 volts from a switch
placed somewhere handy. (This requires that D404 is left in place, or that the other two tracks
leading to D404 are connected.)
Ofcourse, - you may also turn off the mp3-player…
Pin 1 = Pin 3 = ground(GND)
Pin 2 = Left channel
Pin 4 = Right channel
Pin 7 = Tape Mute (12V = mute)

Connectors (13-pin DIN) may be hard to come by(try ELFA)
Or use single stranded copperwires that fits into the connector pins, and solder the audiocable
to them:
Use shielded cable only(shield is connected to ground-pin).
Copper wire
(insulated)
Mute signal ;
12volt from switch