If the power supply is blown, there will be no audio (in most cases). Is it barely audible (ear needs to be almost on the speaker to hear it)? STMicro_TIP36C In some amplifiers, the power supply voltage is regulated. If you're repairing an amplifier and need help, it's important that you do everything possible to make the transfer of information from you to me as efficient as possible. THIS is a plain text file (open with Windows Notepad) that has no formatting and retains the spaces as they should be. It's often good to crop a photo. In most amplifiers, the rail voltage is much too high for the op-amps. With no voltage on pins 8 and 11, it can't have output (most MTX, some Sony and some Xtant amps are different). When using an on-board flash for lighting, it's generally not a good idea. We include fedex insurance on every amplifier, but no one wants to have to fill out insurance paperwork, so package it well! In class D amplifiers, you should not make any substitutions. amplifier You should find the same thing when checking bipolar transistors.

2SC3855 82 - Op-Amps Sometimes it's near the top, sometimes it's buried in the body of the datasheet. Don't Break an Email Thread/Chain: IR_IRFZ46N_LikelyFake - correction, actually mismarked dual diode, Other sites that have information about counterfeit semiconductors: For those who don't have a camera that can take good quality photos (only have cell phone or web cam), you can use a lower quality image and mark up the photo in Irfanview, Microsoft Paint (free with Windows) or your favorite photo editing software. It's a free download and very easy to use. Fasciablaster tools, get baby smooth skin. Motorola_MJL1302A Hitachi_2SK135 If you're new to repair work and you're attempting to repair an amplifier, you're not expected to know everything. If you're interested in doing repair work and you have to constantly wait for someone to provide every minute detail, you probably won't make it in this business. We will never try to save money/time by using an inferior, or non-direct replacement parts. These commonly burn when the power supply fails. A few years ago, I had only a few people asking for help. If that's as it should be, check the voltage on each pin of the TL594 (or whatever driver IC the amp uses). If you're repairing an amplifier that has blown output transistors, you should check the driver transistors also. -We will definitely be adding more to this list as we see fit! The following shelving unit is one that I built to for my shop. The language/terms used in parts of it (the work 'lazy' keeps creeping in) may not be pleasant but it seems that too many people require stronger language to motivate them. The tutorial I sell (click banner below) has MUCH more detailed information and covers a much wider range of amplifiers and problems. linear ultra amplifier compact repair audio parts sold The CHECKING SEMICONDUCTORS page (bottom half of page) has more test procedures for other types of transistors. 78 - Transistor Example Then you simply save the image. If you're looking to buy a scope on eBay, email the auction numbers to me and I'll try to help you get one that is in good working order. In virtually all amplifiers, you will find 'bipolar transistors' (BJTs). All of the PWM control ICs have 5v regulators. Basically, the only difference was the angle at which the photo was taken. If you're using Firefox, open IE or Chrome. Note: There are many types of regulators. Here the wire didn't need to be stripped because there was no electrical connection. Simply have the text/part number facing you and the legs down. When in parallel groups, the components MUST have virtually identical characteristics. If you don't have a digital camera, you probably know someone who will let you borrow their camera. Putting forth a bit of extra effort could mean the difference between getting the desired answer in a few minutes or having it take a few days (or longer). There are controls inside some amps that, if turned, can result in the failure of the amplifier or severe damage to the speakers. For regulated power supplies, the square wave output has a variable duty cycle. If the drivers are tough, the gate resistors will fail. This is at a much higher frequency than that of the square wave but it can still be seen in the 5110 display. This is typically the highest frequency you'll find in the audio section of most class D amps. - If you send us an amplifier, and there turns out to be nothing wrong with it, there will be a $35 testing fee for the amplifier, if the amplifier does need repair, there is no testing fee applied. If your amp only distorts as the output increases (but well before you think it should), you need to confirm that the DC voltage across the B+ and ground terminals of the amp (multimeter probes placed directly on the metal part of the B+ and ground terminals on the amp) is remaining at or above 12v. For most of the transistors using the Japanese numbering system, you add a 2S prefix to the part number. This transistor is the voltage regulator for the drive circuit for the class D amplifier circuit. Note: In some instances, you'll need to supply a reasonably good quality photo so that I can read the circuit board designations and make sense of what you're asking. The class D amps based on the HIP4080 driver IC will only have positive rail voltage. If I find images that are significantly better than what you took with your camera, it's unlikely that you will get a response. In the following image, you can see that virtually all of the components have a circuit board designation. 40 - Potentiometers On the forums, do not ask questions about your amp in a repair thread started by someone else with a similar amp. The small bias compensation transistor prevents the bias current from changing significantly. Noise: The components are all in focus in the image below but the bright reflection is distracting and fatiguing, especially if you have to look at multiple photos or if you have to study the photo for more than a few seconds. The voltage amplifier drives the driver transistors and the driver transistors (2SC3421 and 2SA1358) drive the output transistors. - We try to keep turn around times low by always prioritizing customer repairs before amplifiers for us to sell. Save as GIF, PNG or JPG files. The output transistors drive the speakers. Most amplifiers have switching power supplies. If you say 'the transistors on this side of the board do this' and 'the other ones do this' it gets very confusing to those who are trying to understand, via this very vague description, what you're trying to say. List EVERYTHING, no matter how insignificant it seems. The anode should be directly connected to the negative rail. There is a reminder to list the IC number (circuit board designation) if there is a chance that it will be confused with another IC. Inserting a dropping resistor reduces the voltage drop across the transistor (some is dropped across the resistor before transistor). Try the following in ohms AND diode test modes: Amp Failure: Use it at your own risk. The other other rectifier passes all of the negative pulses to the negative rail capacitor. It's sometimes difficult to explain what this is and posting photos for every time the question is asked is too time consuming. An oscilloscope isn't absolutely required for all repairs but it makes it easier to help with repairs that involve distorted output. It's not important that the face of the scope be well lit when all that's needed is a photo of the displayed waveform. If you continue to break the chain of emails, I'll stop replying. For full range amps, a 100uf cap is typically a good choice. Datasheets can be used to find the specifications like current capacity and maximum operating voltage. ESP I may have more than 100 emails and forum posts in the matter of a few days. The first one is a Tektronix 2230 digital storage scope rated for 100MHz. This amplifier uses an active noise cancelling circuit. When you're asked to measure the voltage on a terminal of a component, you'll almost always have the black probe on a ground reference point. Note: That needs to be cropped. Anything close to 0.6v with no reverse leakage (current flowing through the internal diodes backwards) means the transistor is likely OK. If you don't want your amp to go up in flames, read the following very carefully (don't just skim over it). When measuring most voltages, you will place the black meter probe on the amplifier's primary ground (the amplifier's main ground terminal). amt customizing amp kit parts If you send me a poor quality image, I'll look at the EXIF data. A buzz would tend to be a mid to high frequency noise. If this is too much to ask, please look for help elsewhere.

Problems Concerning Noise or Distortion: Along with that, it's important for your car amplifier to include the input/output options you need, the specifications that indicate great sound, and the flexibility that allows your system to evolve and adapt to future changes and upgrades. IR_IRF3205 The information on this page is for those who are interested in trying to repair their own amplifiers.

The macro mode is useless (I can't find any difference from the normal mode) and the super-macro is only good for photos taken within a couple of inches. This product can be controlled with your voice through Alexa-enabled devices such as Amazon Echo and Amazon Tap. The cathode is directly connected to the base of Q4901 (3rd leg). Start your own thread. If there are no dedicated indicators to tell you which fault has caused the shutdown, you must determine which fault is causing the shutdown and then find the defective components. is a link to this site's home page. Use the amplifier's primary ground for the reference point (black probe) unless otherwise instructed (for those asking for help on either the car audio forum at DIYAudio.com or via email). Looking at the two images below, you can see how the diodes are orientated in the package. Meter Make/Model: Copyright 1995-2022 eBay Inc. All Rights Reserved. That's because it's being asked to dissipate too much power (in the form of heat). The resistor marked 101 is 100 ohms. 60Hz: These are the most useful, especially when the person helping you isn't familiar with the amp. This will prevent the wire from breaking and will make this easy to work with if the amp ever needs to be repaired again. Voltage 'Across' or Voltage 'On' a Component Terminal: If the space doesn't get copied, it's simple enough to add a space before you type the value. This is time consuming and expensive. If you're asked to measure the voltage with the black probe on the source leg of an FET and the red probe on the gate leg of the FET and you don't know which leg is the gate and which is the source, look up the datasheet for the FET and search the datasheet for the pin configuration. In many cases, it's simply an indication that the amp has B+ and remote voltage. To crop, drag a box around the part of the image you want to keep, hit ctrl-y and save. The following image is a wide-shot showing the transistor to the resistor that was added. Pin 7 on the TL594 is ground.

Pin 3:  When this happens, the drivers have to work against the internal short of the FET to try to pull the gate voltage down. The image quality is generally better near the center of the zoom range than it as at either extreme. When asking for help on the forum or via email, please use the circuit board designations when referring to components on the board. Make sure the IC has B+ voltage on its control and B+ inputs.

Without a schematic (many manufacturers won't provide schematics), it can be much tougher. If you don't know what you did last (with regards to the repair on the forum or via email), re-read the thread. The following image shows the parallel components for an audio amplifier. As of this time, most are useless for this purpose. It's a general purpose resistor used to drop voltage in the circuit. I couldn't use the full auto mode with this camera. Many times, a distorted or intermittent channel is due to nothing more than a dirty contact in a potentiometer or a switch. However, it should answer many of the basic questions. Are you using a test speaker appropriate for the amp that you're repairing? Generally, the power supply will be on the end of the amplifier near the B+ and ground terminals. Pin 15:  A simple guide for getting your amplifier repaired. The pin-out of the transistors can have the B, C and E in any of the 3 positions. For most amps, the round-trip for shipping alone will be approximately $60 if you use a shipper with real tracking. Don't try to be a know-it-all. An open (open circuit) is a break in the circuit. This caused the amp to fail. Someone well suited for this type of work would have immediately Googled 'datasheet' and 'IRFZ44' and would have immediately had the answer.

It's generally due to a lack of effort to learn what the camera can or cannot do. Is only one channel distorted or are multiple channels distorted? If there is no short between the center and outer legs of the rectifier, it's likely OK.

Foreword: Turn around time is dependent on how many amplifiers we have before yours, and we will not put anyone ahead of anyone else on the list. In most cases, it's best to use the exact replacement part when repairing an amplifier. If I have them I'll email them to you. When repairing class D amps, one of the questions you're likely to get is 'does the amp have rail-rail oscillation on the output transistors for the class D amp section'. If you have an amp that fails repeatedly after repairing it and you suspect that the transistors may be fakes, break open the package and compare the size of the silicon die to those in the following photos. 100Hz: In the first two photos, you can see the diffuser I used on this camera. Please don't submit cell phone images. http://www.bcae1.com/temp/80hz800hz8khztestsignal01.zip. It's not a special type of resistor. A new section has been added to help you get the information I will need.

Don't Forget the Units! You need to pull the transistors from the board for definitive testing/results. The best way to enjoy your mobile audio experience is to have plenty of power! As you can see it's not nearly as good as the one above. If you want to compare your cell phone images to a 7 year old, lowly 2MP camera (Nikon Coolpix 2200), try to match the quality of the following image. This is only used for low power and initial testing/troubleshooting. IR_IRF3205Z If it uses daughter boards (boards attached to the main board), include photos of those as well. Many people need help repairing their amplifiers but are afraid to ask for help because they don't want to sound like an idiot (asking stupid questions, etc). If you're in a forum where there is nothing but slang, then it's appropriate for you to reply that way. If you can't take the time to get the most out of your camera, I'll assume that your question probably isn't important enough to be answered. This next image is better but there is a limit to the size of the image file that can be posted. If someone isn't familiar with the make/model amp you have, they may be familiar with a clone of the amp and will be able to help you. The most important is to take the stress off of the wire's solder connections. A shorted transistor acts like a valve that's stuck open (passing too much current). For unregulated supplies, the pulse width is constant. The regulators for this amp can be seen HERE. If it's dropping lower, that could be part of the problem and you need to determine why it's dropping. For some reason, people think that they should place the red probe on the positive terminal of the amp when measuring voltage. For more detailed information, follow the links provided. If the first few (or 10, 20, 50) photos you take aren't very good, keep trying. http://www.bcae1.com/temp/100hz300seconds.zip If you're lucky, it has failed alone and replacing it is all you need to do. It's designed to shut the amp down if too much current is drawn from the speaker outputs or when there is an internal fault that causes excessive current draw. The problem is virtually always the same.

You need to download the datasheet for the transistor to determine the pin configuration (B, C, E). This can be done with your favorite software. Cropping Photos: Do you have both positive and negative regulated voltage on the power supply pins of the audio op-amps? If the power supply is blown, it's generally not possible for the audio circuit to trip the protection circuit and therefore the protection LED will not light. Go to page 10a in the directory of the site. For those who read this and see something that they've done and think I'm singling them out, rest assured that I'm not. Not only is the image too small, it doesn't make the most of the frame of the camera. Depending on how busy the person helping you is, that could mean a day or even a week wasted. On the other end of the wire, a similar method was used. If you need a datasheet, use Google and search for 'datasheet' and enter the part number of the component. If you check 3-legged rectifiers in the board, you'll find a short between the outer legs (for the most common 3- legged rectifiers). Many times, the (only) fault is due to a mistake made during the previous repair attempt. In general, the TL594 will have 12v on pins 8, 11 and 12. When measuring voltage, resistance, whatever the units are VERY important. Olympus C-740: On this page, you will see the terms below many times. IR_IRF1010EZ There is a blank space after each pin number to make it easier to read. If you say that you've removed x-parts and reinstall them without letting others know, the next instructions could be with the assumption that those parts are out of the circuit.

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