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.
374 questions
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CP2102 not detected in Windows on custom PCB [closed]
I have a custom PCB with CP2102 but it seems like windows doesn't detect the CP2102. Here is the schematic and the PCB. I also measured the voltage of the pins:
REGIN: 5 V
VDD: 3.3 V
VBUS: 5 V
D+: 2....
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Why is my TIA Circuit for a Free-Space Optical Laser receiver slow? [closed]
As a project, I'm trying to make a free-space optical, laser-based digital communications system. My goal was to reach at least UART max speeds, so about 115 kbps/kHz, but at about 10 kHz I am already ...
- 149
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Errors when building a single-supply Schmitt Trigger?
I was attempting to build a particular Schmitt Trigger in order to learn more about it. It's from the "Design with Operational Amplifiers and Analog Integrated Circuits" by Sergio Franco. On ...
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LED driver board layout with 555 timer
I am working on an LED driver board with 3 SMD LEDs. It consists of two parts: one is the LED driver itself, while the other one is a NE555 timer to generate a PWM signal for dimming. The schematic ...
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Identifying PCB component labeled '100'
I have an aftermarket display for my truck, and earlier this week the display went out. After disassembly, I noticed that a PCB component was rattling around inside of the housing for the display ...
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Circuit only works when I touch some components
I’m having a problem with a part of a project I’m doing. Essentially, I’m trying to build a replica of the Magnavox Odyssey (the first video game console). Part of the console is the summer—a circuit ...
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24VDC output of flyback transformer keeps spiking 2V (spikes to 26VDC)
I'm having this issue where my flyback power supply is not outputting clean 24VDC.
I have attached images of what the scoped waveforms looks like:
...
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MOSFET switching circuit transition issue help
I am having an issue where there happens to be a voltage dip down to 2.2V and due to the POR of the microcontroller which is set at 2.2V it would've dropped lower.
** What Happens :** 3V3 drops down ...
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DIY Contact Mic Amplifier – Struggling with Noise & Stability
I wrote a post some time ago that was deemed chaotic and was consequently deleted. I decided to start over and make a new post with updates and slightly different questions. I hope that’s okay.
I have ...
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BLE Antenna Issues on Custom nRF52840 PCB
I need some help troubleshooting a BLE antenna issue on our custom nRF52840 PCB. Any insights would be greatly appreciated.
Issue:
BLE sometimes advertises on a mobile phone but disappears after a few ...
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Is the TL072 dual op amp the tantalum capacitor of ICs? [closed]
I'm working on a powered subwoofer amplifier that gets its signal from full-range stereo amplifier speaker output. The incoming speaker signal goes to a board that appears to be a lowpass filter with ...
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5V circuit board pulling supply down to 1V
Seeking advice for troubleshooting.
I have an IR receiver/control button circuit board from a Samsung LN26C450E1D TV. The tv is completely dead. There is no standby light and no response to the remote ...
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What is a practical way of testing a triac output?
I work as an HVAC technician and recently, on newer equipment, I've seen hot and chilled water actuators controlled by a triac output. Usually, I see 24vac on/off control.
While troubleshooting a hot ...
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Looking for pointers to find faulty component(s) causing low voltage to light sockets from a ceiling fan control board [closed]
I'm troubleshooting this universal fan speed control board which also controls power to the lightbulb sockets in the same fixture. This module is commonly found in popular ceiling fan products (at ...
- 111
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Reflections on a PCB
We have designed a PCB which consists 6 RF chains. In one single chain it consists of limiter + LNA + SPDT.
We are getting good S parameters (gain, return loss.) The only issue is that we have ...
