Talking about the Analysis and Elimination Method of Simple Fault of Broadcast Power Amplifier
Basic processing method of broadcast power amplifier
(1) No electricity: Check whether the power cord is connected to the fuse, whether the power cord is broken or the fuse is in poor contact, and the fuse is blown → check whether the rectifier bridge or electrolytic components of the power amplifier rectifier are bad, such as rectifier diodes or The bridge stack is replaced with good components and other lines, such as power amplifier tubes, are checked.
(2) The signal level indicator flashes normally, but there is no sound output: first check if the speaker unit is normal. If it is normal, check the speaker lead is normal, that is, check that the terminal is in good contact, normal, that is, open the chassis for visual inspection or ear hearing. Hear or see if the output relay is closed. If the suction is normal, (if there is a universal meter), the front input and output of the measuring relay are directly connected. If not, the contact in the relay is oxidized or fired. That is, the relay is changed normally.
(3) The power light indicates normal sound output, but the output relay is heard. First, use the universal meter to measure whether the power supply of the power amplifier is normal. If it is normal, the signal input terminal of the signal input terminal is connected with the hand. When a large current sound is heard, it is preliminarily determined that the power amplification part is basically normal, that is, whether the signal lead is lightly shaken or not, or if the contact is poor, that is, the measurement with the universal meter is that the line is faulty and normal.
(4) If there is no sound output when the power amplifier is output: that is, it is normal to check the speaker unit. If the terminal has poor contact, it will cause burnt. If the terminal is black, clean it to ensure normal contact, and tighten the screw.
(5) The boot protection light is on: Firstly, use the universal meter to measure whether the horn group has a short circuit, and whether the resistance is reduced (generally normal is not less than 30 Ω). If the resistance value of the external line is normal, it is determined that the power amplifier is faulty, that is, the power is checked.
(6) The possibility that a large phenomenon when the sound is large may be:
1. Poor contact of the signal line;
2. Poor contact of the potentiometer;
3. Signal coupling capacitor;
4. The feedback resistor is in poor contact.
(7) In the case of measuring the normal state of the power amplifier motherboard, there is no sound:
1. The signal line is not connected or the coupling capacitor is open;
2. The front side has no power supply and measures the power supply part;
3, the volume potentiometer is bad;
4. This fault occurs when the operational amplifier IC is bad.
(8) If the pure power amplifier sound is distorted, the faulty part:
1. Power tube soft breakdown;
2. There is no voltage or low voltage between positive and negative voltages;
3. Resistance variable value, etc.
(9) The sound normal level indicator does not work:
1. First measure whether the voltage is normal;
2. Then measure whether the signal is sent;
3. Measure whether the components are damaged.
(10) The treble bass can't be adjusted:
1. Is the potentiometer normal?
2. Whether the voltage is normal;
3. Whether the RC component is normal;
4. Whether the line is connected or has poor contact;
5. Whether there are any solder joints or false solder joints in the solder joints.
Control impedance PCB
Many customers asked us what information we need for impedence control PCB.Here,there are two types for PCB manufacturer,a is single impedance ,just one trace ,two holes .and b is differential impedance,it always go with 1 pair (two trace with same width and space). For single impedance,you just tell us the trace width one which layer and what value you require .For differential impedance,trace width/space,layers and value. Our experience engineers will calculate following your instruction with Polar software.We may change trace width/space or stackup ,but please do not worry, if any changes,we will send you to approve before proceeding. Generally,the tolerance is 10%,and more accurate is 8% .All impedance boards ,we will test here and report.
Impedance Control Board,Impedance Controlled PCB,Gold Fingers PCB,Impedance Control PCB
Storm Circuit Technology Ltd , https://www.stormpcb.com