Troubleshooting a System

The key to finding the problem in a misbehaving sound system is to isolate parts of that system in a logical fashion to track down the fault.

Description of the PROTECT system built into all Autotek amplifiers

The diagnostic system will shut down the amplifier, until reset by turning the head unit off, and back on. This state of affairs will be indicated by the front panel PROTECT LED lighting up under the following conditions:

1 - A sort circuit on the loudspeaker leads.

2 - An internal amplifier fault that causes a DC offset on the loudspeaker output.

Should the amplifier go into protect mode, simply disconnect all RCA and speaker leads, while keeping +12 volt, power ground and remote leads connected.

1.Now turn the amplifier back on, and if the diagnostic LED lights, the amplifier has an internal fault.

2.If not, plug the RCA cables back, and reset the amplifier. If it goes into diagnostic now, the fault lies in the input, either with bad cables or source unit.

3.If the amplifier seems fine with RCA cables plugged in, connect the speakers, one at a time, and if one of the speakers or its wiring is faulty, it will activate the diagnostic system.

Amplifier heatsink overheating

The amplifiers will shut down when the heatsink temperature reaches 80 degrees centigrade, and turn back on once the unit has cooled down below that point. Causes of overheating:

1 - Inadequate cooling - relocate or remount to provide better natural airflow over the fins.

2 - Driving high power levels into low impedances - back off on the volume control, and/or make sure you are not loading the amplifier with less than the recommended loudspeaker impedance.

Low output power

1 - Check that level controls have been set up properly.

2 - Make sure that the battery voltage, as measured at the amplifier’s +12 volt and ground terminals, is 11 volts or more. 3 - Check all +12 volt and ground connections.

Fuses blowing

1 - The use of loudspeaker impedances below the recommended minimums will draw more current - check.

2 - A short on the main +12 volt cable from the battery to the vehicle chassis will cause the main fuse to blow.

3 - If an amplifier fuse blows continually, with only +12 volt, ground and remote leads connected, the amplifier may be faulty.

System does not turn on 1 - Check all fuses.

2 - Check all connections.

3 - Measure the +12 volt and remote turn on voltages at the amplifier terminals. If these are non existent or low, take voltage measurements at fuse holders, distribution blocks, the head unit’s +12 volt and remote leads to localize the problem.

Noise problems

System noise can be divided into two categories, hiss, and electrical interference.

Hiss, or white noise

1 - High levels of white noise usually occurs when amplifier level controls are turned up too high - readjust according to the procedures in section ”Setting up systems after installation for best performance”

2 - Another major problem that can cause excessive hiss, is a noisy head unit - unplug the amplifier input RCA cables, and if the hiss level reduces, the source unit is at fault.

Electrical interference

The inside of an automobile is a very hostile electrical environment. The multitude of electrical systems, such as the ignition system, alternator, fuel pumps, air conditioners, to mention just a few, create radiated electrical fields, as well as noise on the +12 volt supply and ground. Remember to isolate the problem - first unplug amplifier input RCA cables, if the noise is still present, check the speaker leads, if not, plug the RCA’s back, and investigate the source driving the amplifier, one component at a time.

A ticking or whine that changes with engine RPM:

1 - This problem could be caused by radiation pickup of RCA cables too near to a fuel pump or a distributor, for instance, - relocate cables.

2 - Check that the head unit ground is connected straight to the vehicle chassis, and does not use factory wiring for ground.

3 - Try to supply the head unit with a clean +12 volt supply directly from the battery +, instead of using a supply from the in dash wiring/fusebox.

A constant whine:

This type of noise can be more difficult to pinpoint, but is usually caused by some kind of instability, causing oscillations in the system. 1 - Check all connections, especially for good grounds.

2 - Make sure that no speaker leads are shorting to exposed metal on the vehicle chassis.

3 -RCA cables are notorious for their problematic nature, so check that these are good, in particular the shield connections.

SM2-400, SM4-1000, SM1-150.1, SM2-1000, SM4-800 specifications

The AutoTek SM1-100.1, SM4-800, SM2-1200, SM2-1000, and SM1-150.1 are cutting-edge systems designed for efficiency in automotive applications. Each model boasts unique features and technologies, tailored to meet the various needs of automotive professionals.

Starting with the AutoTek SM1-100.1, this model is renowned for its precision and reliability. Designed for measuring various automotive parameters, the SM1-100.1 features an advanced sensor technology that ensures accurate readings under diverse conditions. With a user-friendly interface, operators can easily navigate through its extensive functionalities, making it suitable for both workshops and advanced automotive research.

Next, the AutoTek SM4-800 is a powerhouse of performance, equipped with a robust data processing ability. This model stands out for its rapid analysis capabilities, allowing automotive technicians to diagnose issues swiftly. It integrates seamlessly with existing diagnostic platforms, providing comprehensive reporting features that enhance workflow efficiency. Its durability in harsh working environments makes it a favorite among professionals.

The SM2-1200 represents the pinnacle of technology with its multi-functional capabilities. It offers a versatile approach to automotive diagnostics, capable of handling both electrical and mechanical assessments. This model incorporates wireless connectivity, allowing for real-time data sharing and remote diagnostics. The innovative display technology enhances visibility, even in low-light conditions, making it practical for nighttime repairs.

The SM2-1000 model is distinguished by its mobility and compact design. Perfect for fieldwork, this device is lightweight yet powerful, supporting a wide range of diagnostic tools and attachments. It features an intuitive touchscreen interface, which simplifies complex procedures and reduces training time for users. The longevity of its battery life ensures extended use during critical operations, making it a reliable choice for technicians on the move.

Lastly, the AutoTek SM1-150.1 is engineered for specialized applications, particularly in emission testing and compliance checks. This model integrates state-of-the-art technology for precise emissions measurement, ensuring adherence to environmental standards. Its robust analytics provide insights into vehicle performance, further assisting automotive professionals in making informed decisions.

In summary, the AutoTek series—including the SM1-100.1, SM4-800, SM2-1200, SM2-1000, and SM1-150.1—showcases a blend of innovation, versatility, and reliability. Each model is equipped with advanced features that cater to the evolving demands of the automotive industry. Whether for diagnostics, emissions testing, or real-time data analysis, AutoTek systems stand out as essential tools for professionals aiming to enhance efficiency and improve outcomes in their work.