Questions tagged [troubleshooting]

For questions about troubleshooting circuits. Please note that repair questions must involve specific troubleshooting steps and demonstrate a good understanding of the underlying design of the device being repaired.

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2answers
100 views

Any good resources on general circuit troubleshooting techniques? [closed]

Yesterday, I spent 3 hours troubleshooting an issue where my car had no electrical power and couldn't start or crank. After carefully studying the car's circuit diagrams, removing panels and testing ...
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0answers
35 views

neutral to ground voltage in ungrounded Y connection

A 2 MVA transformer 13.8kV Delta / 400V Y ungrounded neutral the voltage at the LV side of the Main circuit breaker terminals between the neutral and ground is 70 Volts, so, the technician isolated ...
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1answer
36 views

Need help troubleshooting problem with RFID antenna

I do computer support in our public library. Lately I've run into some issues with the RFID readers we use for our check out and staff stations. I'm trying to troubleshoot the problems we're having, ...
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0answers
59 views

ZVS-driver not properly inducing heat

First of all, please forgive me some spelling mistakes, my english isn't the best. Feel free to tell me if I forgot to mention any important information. A few days ago, I built a ZVS-driver circuit, ...
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1answer
68 views

How to drive this solenoid + littleBits?

I have a 5V solenoid, and I am trying to power it from littleBits. I had a littleBits servo bit and cut its wires. The orange wire should be control wire. The reason I want littleBits is because I am ...
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1answer
85 views

Tenma 72-320 scope no trace need help

I am working on a 72-320 Tenma scope. It was supposed to have worked before it was put on a shelf, and after being taken off the shelf it has no trace. I'm pretty sure it's the power supply, but I'm ...
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0answers
129 views

Opamp gain seems too high in dc servo circuit

Hi I’m rather new at troubleshooting TI TL074CD oapamps. I have an amplifier with left and right channels that have independent dc servos. I’ve tripled checked the connected component values, and ...
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2answers
66 views

THAT1646 Distortion on output signal

I am working on an audio project using the THAT1646 balanced output driver (project is a hi-fi mixer for studio insert gear). The project uses a bipolar +/-15V supply. I am experiencing distortion on ...
14
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6answers
1k views

Can I get help troubleshooting a simple hobby electronics circuit? Multimeter not measuring current drawn

I am following the experiment in the popular electronics book - "Make: Electronics third edition". However, when replicating one of the experiments mentioned in the book (specifically ...
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1answer
56 views

Testing a Split Core Transformer based energy monitor circuit using a breadboard

I'm trying to validate my wiring for a variation of this circuit: which is taken from https://www.poweruc.pl/blogs/news/non-invasive-sensor-yhdc-sct013-000-ct-used-with-arduino-sct-013 Before I ...
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1answer
120 views

Weird readings with INA219 Current/volt sensor, Arduino and big, fat scary Lipo

I have a strange situation with an I2C INA219 current/volt meter module (datasheet). In front of me, I have a rather scary 16.8V lipo - its positive output is on the VIN+ of the INA219. The VIN- leads ...
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1answer
57 views

Amplifier clipping output signal [closed]

I constructed a noninverting amplifier with a sine wave input (0.5 Vpp) and observed an output signal that was clipped equally in both the positive and negative regions, to about 2.5 Vpp. I tried to ...
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1answer
66 views

Anyone having a GSM module please confirm. Is it normal to have the terminals of SIM800L EVB antenna shorted?

My SIM800L-EVB GSM module wasn't registering to network even after providing good power supplies. On troubleshooting I found that the terminals A and B, to which the antenna attaches(see img attached) ...
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2answers
100 views

MAX6675 k-type thermocouple ADC is giving high readings

I have designed and built a small fairly simple circuit that uses a MAX6675 chip to take temperature readings from a multiplexed array of 16 k-type thermocouples. Datasheets: MAX6675: https://www....
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2answers
163 views

4 way traffic light using 555 timer

I'm trying to build a 4-way traffic light controller in NI Multisim, using the 555 timer and a decade counter (no microcontrollers allowed). I used this as reference: https://circuits-diy.com/four-way-...
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1answer
60 views

HP E3631A power supply delivers ~32mA on all outputs when the output is OFF but only microamps when the output is ON

I bought a used HP E3631A DC power supply, Triple output: 0- +25V, 0-1A; 0- -25V, 0-1A; 0- 6V, 0-5A 80W With the outputs off, when I connect a DVM (HP 33401A 6.5 Digit meter) to the output on any of ...
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0answers
39 views

NE564 PLL chip operates on PCB only with loop filter pin 14 floating

This circuit has been implemented on my PCB. However, when I test this circuit (without the DRV135UA), it surprised me that the PLL works except Pin 14 of NE564D (V_PLL). At Pin 14, I did not measure ...
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1answer
94 views

AWFUL smell from go kart motor [closed]

I built a mini go kart with an electric scooter motor (MY6812B-12) run off 2 AGM batteries in series and a control box (two way switch, forward and backward, middle is off). I had ridden it around for ...
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1answer
151 views

simple NE5532 preamplifier circuit troubleshooting - sound disappears at upper end of gain potentiometer

I'm a bit lost trying to solve an issue I'm having with the attached microphone preamp circuit. If anyone recognizes what this problem is, I'd be very grateful for any help - thanks so much in any ...
6
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2answers
1k views

Does the circuit troubleshooting tool used in 2001 A Space Odyssey exist in the real world?

In the well known science fiction film 2001 A Space Odyssey there is a scene in which Bowman and Poole are trying to locate the fault in the AE-35 unit. If memory serves, they use a tool which allows ...
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1answer
56 views

Monitor PSU troubleshooting (Monitor sometimes doesn't want to turn on) [closed]

My Packard Bell Viseo 223ws monitor sometimes doesn't power on. I'm guessing that it's a problem with the PSU since it sometimes works flawlessly but other times the power button doesn't even light up....
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1answer
310 views

Device (Rasberry Pi device called a Bobcat 300) continues to burn out power adapters

I have a Rasberry Pi device (a Helium miner, a Bobcat 300), and I'm now on my 6th power adapter for the device, as all of the previous adapters have burnt out after 1 or 2 weeks. Here is the pertinent ...
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1answer
71 views

Too high frequency when building an LC circuit

I am trying to build an LC oscillator for a thesis at my university. I'm aiming for ~3.5 MHz, I would a Helmholz pair with 30 windings each coil and a radius of 1.5 cm, which I calculated to have ...
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1answer
49 views

Photogate is unresponsive - no output signal

I am trying to use this photogate with my Arduino Pro Mini (5V.) I am having no luck getting any readings from it. I measured the voltage across the emitter and got 4.5V, which should be enough to ...
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1answer
141 views

Linear power supply voltage too high

I got myself a good ol' chunky linear power supply at a yard sale. The output is marked 13.8V/25-27A. Switching it on made a spectacular bang with lots of thick white smoke. No biggie, just a large ...
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1answer
61 views

Circuit Board Troubleshooting [closed]

The question is: "Where can I get circuit boards tested or troubleshot?" As My profile shows, I am not an EE, but I'm forced to play one at my company. The following is just some background ...
3
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1answer
89 views

Troubleshoot noise in audio mixer circuit

I have a Soundcraft EPM6 sound mixer. Recently I noticed a click noise in the right channel of a stereo input. The click seems to happen at each period of the sound wave (I feed a 2 Hz signal, and was ...
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1answer
56 views

Why is my level shifter outputting different voltages when connected to AC power

I'm using a level shifter (https://cdn-shop.adafruit.com/datasheets/txb0104.pdf) to interface with an LCD display (https://www.sparkfun.com/products/16398) that runs on 3.3V. When connected to a DC ...
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0answers
80 views

Super weird multimeter behavior, multimeter is jump starting circuit

So I have a custom PCB for a project that has an output port for a pump. The pump is rated for 8-24 VDC, 3-35 W, .3-1.5 A. The starting voltage is 9-13.2 VDC. The PCB is powered by a 24V power supply. ...
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2answers
972 views

Electronic circuit troubleshooting resin - is it normal?

I have just started my first electronics troubleshooting project of trying to fix our family's toaster. One of the first things I learned was that capacitors tend to be commonly faulty parts of a ...
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0answers
49 views

Rotary encoder mistakes knob turned for button pressed

I'm using this encoder https://www.cuidevices.com/product/resource/acz09.pdf to scroll through a menu and I'm having an issue where when you turn it clockwise, it thinks the button was pressed (this ...
3
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1answer
256 views

Why do my FQP30N06L MOSFETs keep dying after being powered up only a few times?

I am having an issue with my circuit. Specifically, with the FQP30N06L MOSFETs failing after only a couple of runs (a run being powering the circuit). I'm using a 24V DC power supply and originally ...
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1answer
105 views

Transformer is generating less voltage than expected

simulate this circuit – Schematic created using CircuitLab I was tried to make a super simple inverter (consisting of a transformer, a single MOSFET, and a capacitor,) which is capable of ...
1
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1answer
109 views

Help identifying broken component

I have this control board from the charging station of a robot lawnmower. The board broke after a failure with its power supply. The board was powered by a 12v lead-acid battery, with a DC-DC ...
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0answers
33 views

Troubleshooting intermittent faults

I recently encountered an issue with an assembly machine: After sitting idle overnight (or sometimes just over lunch, upon pressing the start button the machine would perform the first step of the ...
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0answers
84 views

What type of SMPS is this?

What specific type of SMPS is this? I'm working on troubleshooting no power out. I'm having trouble finding comparable circuits so I can learn how it works. It appears to be some sort of resonant ...
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2answers
84 views

Power supply is flashing and clicking

I tried connecting the output of my 12V 5A power supply to a Peltier module (TEC1-12710) which has a maximum voltage of 12V and max current of 10 amperes. Following this, the power supply LED started ...
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0answers
94 views

TRIAC Failure - Short between input and gate?

I am having a spot of trouble with a TRIAC (T2535-600G) whose gate is triggered by a PIC microcontroller (PIC12F1501)through an opto-isolator (MOC3063SM). Normally, the TRIAC, labeled U2 in the ...
1
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1answer
48 views

Heat Sensitive Fan Project not providing desired output to fan

I recently built a circuit I found online for a temperature sensitive 12 volt DC fan for the summer. The output seems to be regulated to around 0.23 amps which isn't enough to power the fan. I'm still ...
2
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3answers
107 views

High pitch noise when resistive heating elements turn on

I am a service engineer for a company that manufactures lab equipment. I want to ask for electrical engineering help with a problem. We make a product that consists of two parts, one of which is a ...
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0answers
38 views

charge pump - failure analysis

I have a strange behavior on a custom powerstep01 board I designed. This is the Schematic of the CP / BOOT section: simulate this circuit – Schematic created using CircuitLab The values for ...
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0answers
38 views

TPS3619-33 (Backup-Battery Supervisor) overdrawing current at the VBAT path after a few runs

I've been having a few problems in integrating the TPS3619-33 (Backup-Battery Supervisor) into a product that I've been working on for quite a while. After installing a new TPS3619 into the board ...
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0answers
65 views

Strange behavior of 555 timer

Having problems with the 555 timer, I have decided to configure it in the simplest way possible to test its behavior, by controlling only the inputs to the trigger ...
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2answers
198 views

Altium Designer 21 Duplicate Net Name Error

I have a design that is erroring at compilation time with (among other errors) a bunch of duplicate net name errors. I have searched around including reading up on the top result for this problem (...
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0answers
52 views

Troubleshooting component failures in a metal box (that's next to an air band radio transmitter)?

I have a little project that's been experiencing component failures, and I'm having trouble figuring out what to do about it. I think the issue is ESD but that's just a guess. Also I'm a total noob so,...
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0answers
59 views

Ammeter changes the behaviour of my circuit – how?

Calling it a circuit is perhaps overstating it, as it's essentially three black boxes: a Dell MK394 external power supply originally for a desktop PC, a DT9205A multimeter, and a Yaesu FT-450D HF ...
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1answer
39 views

LFO Triangle to Square wave peak distortion

I put together an LFO based off the one in the link below. I swapped out the op amps in the schematic for 741 op amps. Everything works fine, except for the square wave. This is supposed to be the ...
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3answers
204 views

Why does my resistor start smoking when current runs through my circuit?

This is my circuit: simulate this circuit – Schematic created using CircuitLab However, when I wire it up, R2 starts smoking - why does this happen? [Edited to remove incorrect wire]
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0answers
50 views

Tesla Coil Slayer Circuit Not Working [Electroboom's design]

I tried to make the following tesla coil slayer circuit but it doesn't even turn on. Below are some pictures of what I have constructed. I'm using 3 18650 batteries as the power supply. I'm not sure ...
0
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1answer
92 views

Voltage multiplier doesn't work

I built this voltage multiplier today. I hooked it up to my 10kV AC power supply and it worked just fine. It even lit up electronics from far away (from the EM waves generated.) There was just so much ...

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