QSC PowerLight3 Series - 1 Introduction; Restriction of Hazardous Substances Directive (Rohs); Service Bulletins and Updates; The Well-Equipped Service Bench

PL3 Series Service Manual 7
TD-000274-00 Rev. A
Figure 1.1. Load resistor bank
Table 1.1. Load resistor bank switch truth table
1. Introduction
1.1 Restriction of Hazardous Substances Directive (RoHS)
All PowerLight 3 Series amplifiers are manufactured to conform to the European Union’s RoHS Directive, which reduces the amount of
hazardous substances allowed in products for sale within its member nations. In electronic equipment such as audio power amplifiers, this
applies primarily to certain toxic heavy metals, such as lead, which may be present in electronic components, solder, and other parts.
RoHS-compliant materials
When servicing RoHS-compliant amplifiers, it is important for the service technician to use only RoHS-compliant components and solder
(lead-free). All replacement parts provided by QSC for RoHS-compliant products are certified as RoHS compliant.
RoHS-compliant tools
Soldering irons and desoldering apparatus used on RoHS-compliant products must also not be contaminated by hazardous substances, such
as lead. Therefore, you cannot use the same soldering and desoldering tools for RoHS-compliant products and solder as you do for non-
compliant products and solder. You must either use separate soldering irons, desoldering tools and braid, etc., or at the very least designate
separate tips and braids and use only the appropriate ones. If you contaminate a tip or braid, even inadvertently, by using it on a non-
compliant product or solder, you can no longer use it with RoHS-compliant products or solder.
1.2 Service bulletins and updates
Contact QSC Technical Services to make sure you have the most up-to-date service bulletins, schematics, and parts lists for PowerLight 3
Series amplifiers. Service materials may be distributed in hard copy, via fax, and electronically (Adobe Acrobat PDF) via CD-ROMs, FTP from
the QSC web site (www.qscaudio.com), and e-mail.
At the time of this manual’s publication, one service bulletin, PL30001 (PL380 and Standby), had been released for the PowerLight 3
amplifiers.
1.3 The well-equipped service bench
To properly service PowerLight 3 amplifiers, a technician needs the right tools. The
technician’s service bench should have the following equipment:
• Digital multimeter with RMS AC voltage and current
• Digital clamp-on ammeter
• Dual-trace oscilloscope
• Low-distortion audio sine wave generator
• Audio distortion analyzer
• Switching amplifier measurement filter, such as Audio Precision AUX-0025
• Bank of non-inductive load resistors, configurable as 8 ohms
(min. 1500 watts capacity), as 4 ohms (min. 3000 watts), and 2 ohms
(min. 4000 watts). See Figure 1.1.
• Variable AC voltage source, such as a Variac or Powerstat
variable transformer;
For PL325 and PL340: rated current capacity of up to 25 A (for
120 V models) or 12 A (for 230 V models)
For PL380: rated current capacity of up to 50 A (for 120 V models)
or 25 A (for 230 V models)
• Philips and flat screwdrivers
SW1 SW2 SW3
SW4
8Ω 8Ω 8Ω 8Ω
R1, R2: 8 , 1500W non-inductiveΩ
R3, R4: 8 , 1000W min. non-inductiveΩ
R1 R2
R3 R4
SW1 SW2 SW3 SW4
∞Ω (no load)
OFF•••
8Ω
ON OFF OFF OFF
4Ω
ON ON OFF OFF
2Ω
ON ON ON OFF
0Ω (short circuit)
ON • • ON