From 85150f3255f81ca52ef897626728234c47e638f6 Mon Sep 17 00:00:00 2001 From: Ariejan de Vroom Date: Sun, 29 Mar 2020 14:55:36 +0200 Subject: [PATCH] Add post: why I will not repair your amplifier --- ...29-why-i-will-not-repair-your-amplifier.md | 124 ++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 content/posts/2020-03-29-why-i-will-not-repair-your-amplifier.md diff --git a/content/posts/2020-03-29-why-i-will-not-repair-your-amplifier.md b/content/posts/2020-03-29-why-i-will-not-repair-your-amplifier.md new file mode 100644 index 0000000..944aa88 --- /dev/null +++ b/content/posts/2020-03-29-why-i-will-not-repair-your-amplifier.md @@ -0,0 +1,124 @@ ++++ +date = 2020-03-29 +title = "Why I will not repair your amplifier" +tags = ["audiorepair", "rant"] +description = "I get about ten emails a month on average from people who want me to remotely repair their amplifier or TV. Here's why I won't do that." ++++ + +I like tinkering with electronics and one awesome way of doing that is +by [repairing things that are broken](/tags/audiorepair/). I get about ten or more requests +every month from random people from the internet to help them repair there device. My +reaction is always the same: no, I will not. This posts tries to explain why +I say no and what alternative I can offer them. + +When I repair something (or anybody else for that matter), it will cost +something. There's a lot of things that go into a successful repair, +especially of hardware you're not intimately familar with. These are +the steps I normally take: + + 1. Disassemble the device + 1. Isolate and/or reproduce the problem + 1. Find a service manual, datasheet, and other documentation + 1. Theorize a solution to the problem + 1. Find and order replacement parts + 1. Perform the actual repair + 1. Test the repair + 1. Reassemble the device + +Sometimes a problem is obvious. Like the [repair of the HP 34401A](/projects/repair-hp-34401a-bench-multimeter/), +which turned out to be blown fuse. Sometimes the problem is more subtle and difficult to find, like with the +[repair of my Philips 3D LED TV](/projects/repair-philips-42pfl6057h-12/). + +When I'm looking for a repair project, I always do some research first - I'm not blindly buying things +marked 'with defect'. TV's often have a broken screen - which I can't fix. Some amplifiers have issues +with HDMI ports, which I know will require me to purchase a rather expensive replacement circuit board. The +repair will be expensive and not very interesting. If I'm looking to resell a device, those costs add up and +may not make it worth the effort. + +Now imagine some guy, let's call him John, emails you out of the blue: + +> Hello, +> +> I have a problem with my Denon some model or other. There is no sound at all. +> Can you help me repair this. I have no experience with electronics, but I +> do have a screwdriver. +> +> Thanks! + +There are quite a few problems with answering these kinds of messages. + +Let's take a look at some legitimate reasons why your amplifier might not +produce and sound: + + * Did you turn the amplifier on? + * Did you connect speakers? + * To the right outputs? + * That are not blown or shorted? + * With enough power? + * With the correct impedance for your amplifier? + * Is your amp muted or is the volume set to its lowest setting? + * Does the source contain audio? + * Did you select the correct source? + * Did you connect the source correctly? + * Is the source using a digitial format your amp can decode? + * Did you mess with assignable inputs and does the input use the correct audio connector? + * If your source is phono, do you need a pre-amplifier? + * Did you leave your headphones connected? + * If using HDMI or optical, maybe you try a different cable first? + +These are all legit reasons why an amplifier could not produce sound. And this is +just the part to make sure there's actually something broken in the first place. + +Next, the person has little to no experience with electronics. At the very least you +need to understand the dangers of opening an amplifier and what precautions to take +to work with it safely. + +Next, you will need at least a multimeter and maybe even an oscilloscope to find the +exact problem. You will need to look for shorts, high resistances, check diodes and +transistors. + +After that you will need a soldering iron or SMD rework station. You will need solder, +flux, solder wick or solder sucker. Do you know how to use these tools? + +When finished, you need to verify your work - did you put everything back together +correctly? Did you now make any shorts by accident? + +It's not feasible for me to personally to take someone by the hand and guide them +through this process. + +Some people will the reply to me: + +> Can I just ship it to you, then? + +Well, no. + +I don't have time for it. I don't want to risk damaging your stuff beyond repair - +or in transit. And most of all, I'm not interested. This is not my day job, so +I get to be picky. + +So, what _can_ I offer people who ask for my help. + +First of all, if you device is under warranty, take that route. Just go back +to the place you bought it or to the manufacturer and get them to repair it under +warranty. You paid for that service, use it. + +If your device is out of warranty, there are two options. Which you choose depends +on your confidence level for repairing electronics. + +If you don't have any tools available and this is your first time, you're probably +better off finding a local technician to perform the repair. This will cost you +money, and there's a chance the repair cannot be carried out because parts are +no longer available or the cost of the repair is higher than purchasing a new +comparable product. + +If you do have some tools, basic electronics knowledge, and a willingness to +learn more, you should hop over to [/r/AskElectronics](https://www.reddit.com/r/AskElectronics/) +and [/r/audiorepair](https://www.reddit.com/r/audiorepair/). There are over 80,000 people +there who can help you out. Most of them will have more experience than me. Some +might even know your particular device or the problem you're having. + +An added benefit is that your quest will be documented online for others to read. + +Repairing can be great fun. Most people can do it, given you have the right +tools and an eagerness to learn. There's a great bunch of people out there who're +ready to help you out - for your benefit and that of the entire community. \ No newline at end of file