Works, such as the drawing shown: mainly divided into three parts. Namely the power circuit, satellite box amplifier, the subwoofer circuit.
1, power supply circuit (drawing of the bottom part of): 220V electricity through the fuse (F), and switch S entered the transformer primary, transformer secondary output. .
Dual 12V AC, dual 12V fed by VD1 composition of bridge rectifier circuit circuit, after bridge rectifier and C14, C15 (3300UF/25V) after the filtering.
No-load voltage output of about plus or minus 16V or so (root, 2 multiplied by 12V), or A + is positive 16V, A-minus 16V. Positive and negative 16V for the three power amplifier chip. .
TDA2030, UTC2030 provides power. Another way to pass the buck R21, R22, B +, B-12V output about positive and negative for bass preamplifier and. ..
IC4 low-pass filter to provide the supply voltage. .
In this paper, power preamplifier and did not use 78/7912 three-terminal regulator, mill operators replace two, capacitance 3300UF can also be considered.
Provided for the pre-accession LM7812/7912 more stable voltage. .
Second, the left and right channels amplifier (satellite box amplifier), the left and right channels for exactly the same principle. Here I only left channel with drawings, for example, for a presentation.
Figure: RIN for the signal input through coupling capacitor C23 into the volume potentiometer (volume potentiometer by three pins, and the C23 is connected to input..
The output also called sliding side, another PIN to ground), adjust the volume after the signal enters the R1/C3 's treble boost circuit, this circuit can raise a certain amount.
High-frequency signal to the sound clearer. Later the signal through coupling capacitor C1 into the left channel amplifier, model UTC2030 of a foot, after power amplification, by the. .
2030 output in the fourth leg to promote satellite box. In the figure a feedback resistor R7, R9 to R7/2030 the magnification of the chip. As a result, adjust the resistance of the R7.
, You can adjust the magnification. R11/C7 compensation network for the speaker. .
Third, the subwoofer circuit. From the left and right channels via two 10K resistor R5 and R6 back to coupling capacitor C11, then signal enters the IC4, model 3 feet, JRC4558 diagram.
IC4A for the ultra-low noise preamplifier. R201T amplification of this amplifier is set to 6 times. (R17/R18), after pre-amplification in order to ensure sufficient. .
Driving voltage is large enough, given the volume of space that is large enough. 4558-1 foot to front output, after entering the IC4B R19, C9, C10, R20 consisting of low-pass filter.
The role of low-pass filter cut-off less than 200HZ low-frequency signal, R20 and C10 determine the cutoff frequency. (Specific for each manufacturer to set the cut-off frequency slightly different). .
After the IC4B output-C19, and volume potentiometer input connected, adjust the subwoofer's volume by sliding end output into the potentiometer and the subwoofer amplifier IC3;.
TDA2030A, this amplifier circuit consistent with the principles and the satellites. 4 pin to output, to promote the subwoofer sound. .
The above is the basic working principle R201T. in passing that in the figure a Department ID is wrong: that is, the 1 foot TDA2030A input should be marked as "+" phase.
Drawing against the standard of 1,2 feet. .
Note: Cruiser R1900TII, 1800TII. hussard V23SE, M200, M20W hivi, M20L T120. in chip LM1875T. it works with this article.
The TDA2030A line. .
2. maintenance method: .1 speaker.
Grasp the basic principles of the circuit, the multiplier of the maintenance. In fact, doctors see patients as maintenance of sound, like, pay attention to, "look, smell, questioning." .
Maintenance before doing: audio experiences a failure, do not hurry to start. To ask the user to use: it appears.
Barrier before and after the sound has. .
What are the exception, for example.
No, "Kaka," the noise, whether the smell odor, smoke, etc. Did you see the sound, so you can quickly understand the tone. .
Response status. Experience sound silent or Mono etc, dont judge faults for reproducing itself; rather, it is first necessary to exclude the signal source and first.
Cable problems. Such as check the status of the computer is placed on mute the system volume is not transferred to the smallest seat? ? ? ? Whether the balance control. .
The location in the Middle???? determined the sound card or DVD/CD signal no problem, check the output of audio connectors, sometimes, the amount of contact non-connector.
Will result in mono or a noise. Another. The satellites have to check the wiring clip, with or without loose and so on. (Sometimes you can swap the two the satellites to do..
Ding Wei.
Star box and amplifier circuit is good or bad); determine the signal source and connecting cable, no problem, have not ruled out a failure, before deciding to repair your speaker disassembly. .
The following spoke in the speaker R201T some common troubleshooting methods:.
First, boot without any response, satellites and subwoofer are not audible. (At this point no potentiometers to adjust the volume of two reactions). This failure is basically a power supply failure. .
(Because three amplifier chip at a very low probability of damage). Multimedia stereo fuse if installed outside. We can loosen insurance cover, remove the fuse.
Observation: If. .
Insurance is solubility broken, do not hurry to put on the new insurance. We can observe in the case of damage insurance: If the fuse is intermediate or two, no obvious.
Black burn marks. .
Track. It can be estimated, it is no accident damage insurance. (Because the AC voltage higher reason) then use the same specification fuse replacement generally cannot be ruled out. (If fuse installed.
To the host box of. .
The need to disassemble the machine to be able to check out the insurance cover).
If the burning fuse of a dark wall, estimated to be burnt transformer (or turn to turn short circuit) and the other rectifier filter circuit or short circuit in a device can also cause this phenomenon. Time. .
We can observe.
Compression device with or without odor, take a look at whether the traces of burning. Universal table can also check whether the output voltage of the secondary. If the normal output transformer, then to check the four rectifier. .
Possession of a short circuit without breakdown.
Capacitor short circuit and so on. Until the identified short circuit components. .
Second, Mono. For example, the left channel, we can remove the left channel satellite box to access right channel satellite box. If satellite box at this point, you can confirm the fault.
Reason for the left channel. .
Satellite box speaker has failed or burned. If you accept the right satellite box, the fault persists, illustrating the sound is good, just left channel amplifier circuit is damaged. (Or you can leave behind R201T.
Audio input line. .
Left and right channels are switched off judgment 2. .1 speakers working state). So, how to repair the left channel of the amplifier circuit?????, we look at the drawings, diagrams and I have A goal.
, B, C, D, E, a few. .
"Key points". IC2 is the left channel amplifier circuit, we can use a simple and effective "injecting" (also known as signal interference method), you can use the hospital.
Or with metal forceps. .
His small screwdriver (hand touch the metal parts), direct touch point b on the diagram. The power amplifier chip 1 feet, at which point the speaker should be larger "Titicaca", if you don't have to.
So basically sentence. .
Broken power amplifier chip is already OVER. We use the same model of the chip replaced. UTC2030 UTC2030, can be used to direct substitution TDA2030A TDA2030.
Also be noted, TDA2030A inverting input of the R10 and C6 disconnected or damaged, may cause obstruction or even a silent voice. In addition, A --- B point with circuit board copper. .
Foil cut can also generate the left channel. The above check.
Repair method on the premise that: IC2 operating voltage under normal circumstances. (That is 3 feet for the negative 16V, 5 feet is positive 16V or so). .
3. no sound from the subwoofer. We can direct universal table of R * 1 bombarda retaining measurement, speaker should have smaller "UC card", otherwise the loudspeaker has been corrupted. Horn normal.
, We. .
Still using signal injection method, in order to quickly find the point of failure, usually from the "after"----"before" all rows. The power amplifier line after the class is first made, no fault signal injection to the words.
Before an injection signal. .
Such as drawings: F point injection signal interference, Bass trumpet should have "noise" nervous or overhaul amplifier TDA2030. If rattling sound good, but does not work, the subwoofer.
We can check it. .
Bass volume potentiometer, potentiometer, also does not resolve the problem, check the IC4. IC4 serves two purposes, one is a preamplifier, a..
Were low-pass filter. If the IC. .
4 power supply is not working properly or is damaged, it will cause a subwoofer. (Note that the 8 feet for IC4 is 12V, 4 pin 12V for negative). Before carrying out such checks,.
We have to visually look at the circuit board with or without fracture, with or without obvious burned components of the phenomenon. This can avoid detours. .
Continued on, TDA2030A is relatively easy to damage the device, apart from signal injection. We also can use the following method to quickly judge the 2030 is good or bad-we tested the chip.
The power supply is normal, that is 5 feet is positive 16V, 3-pin negative 16V. In the case of no signal input, while three-pin voltage should be zero. If the measured 4 feet. .
(Amplifier output) of the DC voltage output, (or even 16V or so), determine the chip has been corrupted. Special needs attention: TDA2030A (LM1875).
Pin 3 and thermal contact surface is connected, if the cooling plate surface and the heat insulation between the pieces do not mat, maintenance must bear in mind: Do not touch the ground plate heat or power lines. .
Otherwise you may cause damage to the chips.
Fourth, adjust the potentiometer, the speakers have Kaka in the noise. This failure can be WD - 40 cleaning. References: http://www. . Edifier. .com / cgi-bin / bbs / bbs. . Cgi? U = bbs & id = 20040216225824sb serious wear, with the same specifications potentiometer substitution. .
(5), trumpet, "howl" sound or a considerable amount of noise. When the rectifier circuit a rectifier diode breakdown short circuit, or filter capacitor failure. May cause this failure.
How to determine whether the failure of filter capacitor do? ? ? ? We can detect the A +, A-voltage. Normal voltage should be around 15V. When the detected voltage of a group of only about 10V when. .
Estimate the appropriate filter capacitor. For example, only A + 10V, C14 had expired, lost its role filtering. Used with the specifications of capacitance substitution.
6, subwoofer does not play music in a great time, "Weng Weng" sound. Even if the input signal lines pulled, Weng Weng still great, has never been able to eliminate. The general phenomenon of this phenomenon is. .
Bass channel circuit failure, most likely is TDA2030A chip damage. TDA2030 4 feet caused the output DC voltage, so that the Horn boring "Ong" sound.
Simply replace the amplifier chip can solve the problem. .
See reply to 5 in the third picture, we can quickly identify NE5532 TDA2030A pins, and order. Plates 1-dotted with in as NE5532 (JRC4558) pin 1 foot. The following figure to all pins of the operational amplifier-identification. At a glance.
NE5532 (JRC4558) pin: 1 to op amp output, 2 for the inverting input, 3 pin input. . 5 feet of another op amp inverting input, inverting input 6 feet, 7 feet out. . 4 feet for the negative voltage, 8-pin positive voltage. .
In the middle of the picture material is 2. 1 speaker commonly used TDA2030A amplifier chip, the chip is a dual in-line package. Left-right: close to the thermal plate for 2, 4 feet. Front row followed by the 1, 3, 5 feet. (LM1875 pins are exactly the same).
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