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.

Filter by
Sorted by
Tagged with
1
vote
0answers
49 views

What is this checkered pattern in altium when placing tracks?

I'm learning altium and trying to re-route an existing board that I have not that much experience with I've found this checkered pattern in some tracks that Altium is being very annoying at: They ...
0
votes
1answer
38 views

Trouble Using Optocoupler (AL-ZARD DST-1R4P-N)

I'm attempting to use an Al-Zard DST-1R4P-N optocoupler (3.3v to 12v) to take the 3.3v signal from a Raspberry Pi and control a 12v solenoid. The image below represents how I'm attempting to wire it ...
0
votes
0answers
38 views

PCB troubleshooting - newbie

I have a real beginner question;) I have a small quadcopter that stopped working at some point. in theory it works like this: I turn on the remote control (so far it's ok) and then I attach the lipo ...
0
votes
2answers
79 views

Precautionary Discharging Capacitor went Terribly Wrong | SMPS [closed]

I wanted to check the fuse of SMPS pictured. In order to safely conduct the procedure I followed the discharging procedure as provided in many tutorial videos i.e (connecting the end of the ...
0
votes
1answer
38 views

Troubleshooting Switch Mode Power Supply

I am trying to troubleshoot switch mode power supply from HP workstation. I have done visual inspection and didnt find any anomalies on the capacitors. I reckon that the culprit might be the fuse as ...
0
votes
2answers
84 views

What is the best way to solder a large flat SMD shunt resistor so as to minimize joint resistance?

I have a BLDC motor controller that uses a high side 0.001 ohm current sense resistor (CSS2H-5930K-1L00F) and a MAX40201FAUA (50 V/V) to measure the current during motor operation via a Teensy 3.6 ADC....
0
votes
1answer
44 views

LM7805 Voltage Regulator stops working when input voltage increases

I have the following circuit: simulate this circuit – Schematic created using CircuitLab I designed the PCB, had it printed and now I am testing it. When I power it up the following happens: ...
3
votes
1answer
93 views

ESP8266 loses wifi connection on switching a load

I am trying to switch a roller shutter belt winder (RADEMACHER RolloTron Basic 1100) with an AI-Thinker ESP8266 ESP-12E module. As software ESPhome is used. Most of the time the ESP8266 loses its wifi ...
0
votes
0answers
45 views

Troubleshooting butterworth bandpass gain stage issues

I am having issues solving the gain stage section of my bandpass filter design. I used a multiple feedback 6th order lowpass and a 6th order sallen-key high pass to get a bandpass filter with cutoff ...
0
votes
1answer
37 views

Help Troubleshooting Relay for Vehicle Offroad Lights

I am wiring up 2x 55W Halogen lights and 2x 100W Halogen lights on my '01 Subaru Outback. I want all 4 lights to come on when I turn the switch on. I created the wiring diagram which I followed during ...
0
votes
1answer
39 views

RN42 Bluetooth module doesn't turn on. Any tips for troubleshooting?

I've made a PCB that uses a RN42 module. Here's the datasheet and a user's guide (albeit for an eval kit, rather than standalone module). The situation: I power up the module with 3.3 V, and the ...
0
votes
1answer
43 views

Why isn't my the LTspice cutoff frequency for my multiple feedback low pass filter not matching?

I am designing a 6th order multiple feedback lowpass filter with cutoff frequency at 1000 Hz. I wrote a matlab script that calculated the capacitor and restore values. I combined all transfer ...
0
votes
0answers
34 views

How to fix incorrect cutoff frequency using multiple feedback butterworth lowpass filter

I designed a 6th order low pass Butterworth filter using multiple feedback topology (Fc = 500 Hz). But when I run it in LTSpice, the cutoff frequency is seen shifted far below to around 10Hz. Why is ...
0
votes
1answer
19 views

Troubleshooting connections between strips of WS2811 Addressable RGB LEDs

I'm hoping for help troubleshooting a light array I built for my son's room. I strung together 8 strips of WS2811 addressable RGB LEDs (30 per strip). I soldered all the strings together, and tested ...
2
votes
1answer
131 views

IR led extremely slow to turn completely off?

I'm working on a project where I'm simply reading the amount of light emitting from an IR led with an IR sensor. For some reason, after the IR led reaches full luminosity, it takes a minimum, whopping ...
0
votes
1answer
92 views

Help confirming probable dead flyback diode

I'm a beginner in electronics and not really my field, but I have a dead network switch (Unifi US-24-250W) which, from what I found, tends to have defective PSUs. The PSU on mine seems to be working ...
2
votes
1answer
143 views

Finding cause of faint burning smell in active PA speaker [closed]

I play electric percussion in local theatres. I use an active PA speaker with a 12" driver and a tweeter: a Wharfedale Pro EVP-X12P, which I bought in 2011. I tilt it on a guitar amp stand, to point ...
0
votes
2answers
49 views

Need Help Trouble Shooting A HP 8559A Spectrum Analyzer

I recently acquired an HP 8559A spectrum analyzer however instead of the HP182T display it was supposed to have it shipped with an HP180C display. I am unable to get the display to output a signal (I ...
0
votes
2answers
100 views

Rogue resistance between Vout and GND in LDO circuit

I'm currently developing a circuit as seen here:. I had some suggestions to check my Iout to ensure that I wasn't drawing so much current that I was causing an overheat. After a little checking I ...
1
vote
1answer
117 views

H-Bridge shoot through at high voltage problem - Don't know the cause

I have this H-bridge circuit The circuit is for driving a 180VDC motor, it is built to taking in the High Bus voltage from 169VDC to 340VDC. it works with no problem up to 310VDC. However, at 340VDC, ...
3
votes
2answers
163 views

What is causing a white scale buildup at copper pin connection on LED light sticks and how can they be cleaned?

Can someone explain what is causing this white scale to appear on the copper pins and on the block of this LED light connection? The seal at the connection is supposed to be watertight. On occasion, ...
0
votes
0answers
74 views

How to rule out that you have a faulty power supply?

Just for context: I'm trying to code an ESP8266-ESP01 through an arduino, but I'm failing and my primary suspect, as per other forum issues I read, is that the power supply is the fault. I've tried ...
0
votes
1answer
54 views

Custom STM8L dev board not working

I designed a dev board for the STM8L151F2, and even using an external programmer and external power the STM8 has only been able to be programmed twice. Here's the schematic, everything done in eagle. ...
0
votes
0answers
39 views

Pin assignments do not appear to be assigning in bdf - Quartus 17.1

Following the pin assignment diagram in the device manual for my Max 10 DE10-Lite, I assigned all the correct pins to their associated inputs and outputs as seen below: However, when I go back to my ...
0
votes
2answers
252 views

Low pass filter not working properly

This is the pass band that I'm using to filter some EMG signals through electrodes. When I test it with multisim it works really well as you can see, but when I test it with real equipment (...
0
votes
1answer
135 views

Need help on troubleshooting PCB circuit

I recently got a freelancer to design a push-button latching circuit that powers a 12VDC motor from a 1S1P Li-Po cell. I have soldered all the components but the board does not seem to work properly. ...
0
votes
1answer
60 views

Need help troubleshooting after short-circuit, with heaters and thermocouples

There was a short circuit in one of the furnace that I designed. Description of the furnace and its components: The furnace is a copper tube, with 1/2 inch thickness, and 10 equally spaced 1/4 inch ...
0
votes
1answer
40 views

DC Power supply stopped working properly

When I needed to set a maximum current I shorted the outputs and set the desired value with the current knobs. Now it doesn't work for some reason. Here's a short video. Any idea what's going on?
0
votes
2answers
129 views

Reading data from Pressure Sensor

I am having trouble reading data from a pressure sensor using MATLAB. The pressure sensor is connected to an NI 9219 Analog Input Device. Firstly, i tested the device to make sure it is working using ...
-1
votes
2answers
77 views

Need help with circuit troubleshooting, Red LED constantly lights up

I have problem with the following circuit below. The Red LED is constantly lighting up, but I cannot figure out why. For the LM339, the voltage readings I get are as below. Shouldnt Out1, Out3 and ...
2
votes
0answers
78 views

Need help troubleshooting Teensy 3.6 SPI to DAC8568

running out of things to check with this problem I'm having. I designed a board around the Teensy 3.6 microprocessor, and I wanted to connect a DAC8568 chip to it for some analog outputs. It works ...
0
votes
1answer
56 views

DC voltmeter gives unknown reading when powered

I just bought a DC 3 wired voltmeter and it was working perfectly. Here is it image: I used the yellow wire for measuring the voltages. But for some reason, I desoldered the wires and soldered pin ...
1
vote
2answers
92 views

Confirm transformer fault vs markings / spec

I'm trying to troubleshoot a German ceramics kiln controller from about 1989. There is a 100ma glass fuse in front of this PCB transformer that blows after a second or two when power is applied. ...
1
vote
2answers
92 views

Chua's circuit producing unexpected waves?

I have built the Chua's circuit in the following diagram: I then hook it to a soundcard oscilloscope. It produces the following wave: Such waves doesn't change no matter how many times I repeated ...
0
votes
0answers
55 views

Chua's circuit's pattern not fully shown

I have made a Chua's circuit, and hooked a soundcard oscilloscope to it, to measure the voltage across C1 and C2. Circuit diagram: Source:Kennedy 92(pdf). Software used: soundcard scope. The ...
0
votes
0answers
37 views

USB detected, no communication

I had a device come with no USB cable. Since it used a proprietary USB connector on the device side, I decided to solder a male USB A cable directly on the motherboard pins. The USB device is ...
0
votes
1answer
95 views

Strategies for troubleshooting buck converter

I'm trying to troubleshoot a tps65261rhbr triple synchronous buck converter from 12V producing 1.8V, 3.3V and 5V. The 3.3V and 1.8V are stable and well-functioning but the 5V is not. An oscilloscope ...
0
votes
1answer
126 views

Why the DC voltmeter does not read zero when it measures an AC signal?(Chua's circuit) [duplicate]

I have made a Chua's circuit that is nearly the same as the one in Kennedy 92(pdf). I don't have an oscilloscope yet, so I connect a DC voltmeter at the place where probes of oscilloscopes should be ...
1
vote
2answers
119 views

Help With Buffer Amplifier/Filter Type Circuit

I’m having trouble with a circuit I designed and I would be greatly appreciative if I can get some help here. The circuit I designed is a buffer amplifier type design intended to take two channels of ...
-1
votes
1answer
2k views

How to check (6 pin) PCI-E power rail on a pc powersupply?

Could anyone tell me if and how i might verify whether or not a PCI-Express 6 pin power lead on a PC is outputting correct voltage(s) ? A while back, I decided to try to refurbish a graphics card ...
2
votes
1answer
86 views

Current monitor circuit not working

For part of a project, I am needing to monitor the current draw of 4 low power loads simultaneously. I like experimenting with circuits and I found one online in a TI application note (AN-31 page 35) ...
0
votes
0answers
77 views

HJS-480-0-24 Power Supply begins smelling like burning plastic after 30 seconds of running

I recently purchased a HJS-480-0-24 power supply off Banggood and I tested it out by running a 150 watt heater. After 30 seconds the power supply began to smell like burning plastic, so I immediately ...
0
votes
1answer
207 views

tube amp - high power supply voltage ?! troubleshooting

So I started working with troubleshooting a channel imbalance on the schematic attached, 12ax7 + 6L6GC push pull. But the problem seems to be a bit different... My voltages seem to be a bit hot!! (a ...
0
votes
2answers
728 views

Constant flickering of TFT Display

We have an issue with our TFT display. The display constantly flickers while displaying. What are common causes for flickering in this type of display? How can we resolve this issue? It's a 3.5 inch ...
1
vote
1answer
169 views

Power button behaving as OFF-(ON) momentary switch rather than latching- Troubleshooting

I have a device which doesn't turn on normally when you press the power button like it did before. You have to keep holding it down for it to remain on. As soon as you let go, it turns back off. In ...
0
votes
1answer
99 views

Turnigy servo motor needs push to start

I currently have an inspection robot deployed in a remote part of Africa that has a failing Turnigy TGY-6114MD servo. The issue started happening during normal operation and was working fine ...
2
votes
2answers
49 views

LMR33630A, my built circuit doesn't match the expected output

Using TI's "power designer", I've taken their 33630A and designed it for a 5v output. My actual circuit has a slightly different value for the divider to raise the voltage up to about 5.2v, otherwise ...
0
votes
1answer
113 views

Avoid fire on a battery-powered device [closed]

I was trying to repair a battery-powered electric razor when I suspect there was a short-circuit. The device started heating and it began smoking a bit so I took it and put it in a bowl full of water....
0
votes
0answers
38 views

What are some techniques to troubleshoot a second order sigma delta loop?

I have designed a slightly modified second order (3-bit) multi-bit incremental sigma delta modulator (IDSM) in simulink (system level). The SNR that I get is 45dB, which is not as expected. But ...
0
votes
2answers
477 views

Strange behavior of the DALI controlled luminaires

I faced a strange behavior of a DALI controlled LED luminaires circuit. I have 48 LED luimianires with a MeanWell ELG150-C700-DA drivers connaected according to the scheme below: I commissioned the ...