MURA BM54 - User Manual

1
BM54 AMP Repair kit
1.Overview
Thank you for purchasing BM54 repair kit.
Along with this guide it should help you retain sound on all channels on BM54 radios suffering poweramp failure which is
common to this type of module. Upon completion you’ll have a fully functional BM54 with no recurring problem and
same or better sound than stock power amplifier. The poweramp IC used in this kit has better electrical characteristics,
and is better protected against short circuit, over temperature and overvoltage. It has better supply filtering and as the
stock model has an output pin for clipping detection (distortion).
2. Package contents
Your kit should contain the following:
-Amp PCB 4x40w audio amp with standby/clip detector control complete with components soldered
-connecting wires (output wires, input coax cables, supply
-Two screws with nuts/washers
-this guide
Mura Car Accessories (MCA)
Str Doctor Iacob Felix, et 1, apt 1 011031,
Bucuresti, sector 1
T: (+4) 0756 76 79 64 | (+4) 0747 47 37 52
W: https://mca.electricmura.ro/ro
E: contact@mca.electricmura.ro

Summary

1. Overview

2. Package Contents

3. Mounting; Installation Instructions

3.1 Disassembly

Steps involved in disassembling the BM54 unit for repair.

Open Top Cover

Instruction to open the top cover of the BM54 unit.

Remove Screws (1)

Instruction to remove the first set of screws during disassembly.

Remove Screws (2)

Instruction to remove the second set of screws during disassembly.

Remove Clip (3)

Instruction to remove the retaining clip during disassembly.

Remove Main BM54 PCB from Housing

Step to remove the main BM54 printed circuit board from its housing.

3.2 Preliminary Work with the Board

Pre-installation steps required on the main board.

Cut Traces to Isolate Old Poweramps

Cut specific traces on the board to isolate the old poweramps.

3.3 Connection Points

Diagram showing connection points on the BM54 poweramp kit.

BM54 Main PCB Connection;Soldering Points

Details connection and soldering points on the BM54 main PCB.

Output (Speaker) Connections

Instructions for connecting speaker outputs to the BM54 board.

Power Supply Soldering Points

Illustrates the soldering points for power supply connections.

Clip Detector Soldering Point

Identifies the specific soldering point for the clip detector.

Connect and Solder Cables

Connect and solder the provided cables to their respective locations.

Mounting Board and PCB in Chassis

Drill holes, mount the poweramp board, main PCB, and retaining clip.

Important Warnings

Important Warnings

Critical warnings regarding washer placement and spacer use to prevent short circuits.

4. Signal Description

Supply Signals

Defines VCC as supply voltage and GND as ground for the poweramp circuit.

Output;Speaker Signals

Describes activation signals for rear and front speakers (RR, FR, RL, FL).

Input Signals

Defines input signals for rear right, front right, rear left, and front left channels.

Other Signals

Defines STB_mute (standby/mute) and CD (clip detector) connections.

Critical Warnings

Common Installation Mistakes and Risks

Details common errors in trace cutting and component removal leading to damage.

MURA BM54 Specifications

General

Brand	MURA
Model	BM54
Category	Computer Hardware
Language	English