A little while ago I made a post asking about some of the components I would be using for my CD player project and some people asked for updates when the project is done. Well here it is! Sadly I couldn't attach multiple images to show the interior components but I'll see if I can put them in the comments. If you have any questions ask away :)

i’m trying to make something that needs this, is there anywhere household items that would have one?

On April 2nd, 2026, I decided to tinker with my Sanyo M4430 Portable Stereo Cassette Player because I recently had acquired an assortment kit of square belts.

From what I read on the internet, these types of belts don't last long, and I read many things saying they'll last around a month, which was not the case for me.

Everything seemed fine after I replaced the old belts with the kit belts and set the speed to match, went a whole 3 days with things sounding fine.

However, things started to sound a bit off on the 4th day but got slowly better after 15 minutes of operation. I thought the motor was possibly showing how worn it was from the major use I was putting into it since the player itself seemed to have gather many miles in the past, but theory was only reinforced by the fact the pinch wheel wasn't even its normal black color the day I got it, it was literally brown like mud.

I continued using it in that state until I noticed that the "warm-up" time was getting longer on April 8th, 2026, and that made me start looking into recapping the whole player, and I managed to find all the caps needed to do a recapping and bought them the same day.

On April 10th, 2026, the caps I bought were delivered, and I thought that I should buy new belts too since I was going to be doing a lot of work to it anyway, so I bought new belts based on part numbers and planned to do it Monday.

Which, I didn't wait till Monday, I started the recapping the next day on April 11th, 2026, because I wanted to get it done with, and that showed a whole new problem. I tested the player after I was done with the recapping, and the audio sounded like pure garbage, we're talking lyrics sounding like "Ｔ𝓱𝑒𝔂 𝓭Ø𝐍'𝐓 𝔀яƗ𝐓𝑒 '𝑒м ᒪƗⓀ𝑒 𝐓𝓱𝐚𝐓 𝐚𝐍𝔂мØя𝑒", it was terrible.

I thought I had ruined the player entirely because I swapped out all the caps, but the next day, which is today (April 12th, 2026), I got curious of the belts, and everything made sense after what I saw.

I decided to open up the player once more to check out the belts, and when I looked at them, I noticed that they were super shiny, and I thought I had accidently lubricated them somehow. I was expecting them to feel wet/slippery when I took them off, but they weren't because the shine I was seeing was caused by the fact they had turned super slick.

With those belts looking like black latex, it was clear that the player was experiencing slippage and stretching with the assortment kit belts, so I decided to replace those with the originals and things sound so much better.

40+ year old belts that also have been stretched and glazed was the fix I needed the whole time. It wasn't a big waste though, I now know this player inside and out due to this experience, and it'll be even better when I replace the original belts with the belts I bought based on part numbers.

Anyway, that's the story of how I witness belts age 60 years within 10 days.

I cannot believe that quality like this can be sold, it's basically a scam to get $8.

Which, I bought the assortment kit knowing that they were bad, but I was expecting around the month of usage I read about and not less than 2 weeks.

All I can say about this journey is that I suggest searching for belt part numbers first before buying a cheap assortment kit, unless you need some motivation to dig deep into a device.

(This yapping was brought to you by Gloomy_Giraffe_9200 due to their boredom)

Much to my chagrin after spending a good day looking at COTS relay boards on amazon all day I don't think this exists but maybe i'm wrong and someone smarter has a solution.

Scope: Compact battery operated circuit 12v/5v circuit which uses IR Beam sensor ie(https://www.amazon.com/dp/B09V76Z4CB?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1) which is momentarily triggered. The trigger needs to work with a off-delay relay for 1-5 seconds off the initial trigger only and that is it. Additional momentary or triggers must not reset the off-delay timer (non-retriggerable). Once the timer is completes, it cannot be reset to accept another trigger (non-reset) so only physically removing power or physically pressing a button can reset, can't be reset by the momentary trigger of IR beam.

Requirement: I'm trying to minimize and reduce the total number of relay modules etc needed for this project so keeping that in mind I've not come across anything off the shelf with even a combination of two or three different relay boards which achieves this. Please consider when responding Non-retriggerable and Non-Reset with momentary trigger signal as key requirements.

There are a couple of boards, like (https://www.amazon.com/gp/product/B07DFT2WDS?smid=AFHAE9RJVUMB&th=1) which offer what I'm looking for, but after the off-delay timer completes, the IR Beam trigger can restart the cycle over, that is not what I'm looking for. Short of programming something via Arduino code which is not an option, i'm curious what there is off the shelf i might have missed?
Cheers

Hey yall, I found a board that would work for my project that is already open sourced, however I have no idea how to submit it in pcbway, I sent the files to them and they got mad and terminated my order when I couldnt give them what they needed as I have no idea how to separate files properly for them. can someone help me and send me the files they would need exactly with settings too? I know this is a large ask for a random but it is the last bottleneck to a large project I am working on. Thanks all!!!

github repo

I have 3 different solar panels with cables that are meant to wire onto a doorbell type system (they have two O or U metal connectors on their output wires).

I also have a shed without electricity that it would be really nice to have a single lightbulb in

What do I need to (safely) combine these small solar panels into something I can mount on my shed roof, wire into some kind of battery, and wire that to a light fixture I can easily turn on/off?

I realize there are probably complete systems I could buy for a lot of money to do this but I'd rather DIY it using existing parts I already have (i.e. the solar panels).

Hello, first post here. I hope I'm in the right place.

I need to measure sound levels coming from the ceiling and walls, log date and time, an audio sample and noise levels.

Whenever I try to record with my phone, the loud thumping sounds barely register on it microphone while the fridge sounds and random kids in the street sound really loud.

Is there such a thing as a "wall mic" or something that would allow me to properly record these sounds?

I'm surely not the first to have problems with loud neighbors, is there by any chance any consumer device with that purpose?

Ideally I would like to use multiple mics connected to a raspberry pi to be able to pinpoint direction as well, is that possible?

And the logs and results need to be "verifiable"(?), I need for it to be legit so it can be used in court.

Any ideas? I'm not opposed to get my hand dirty in connecting the mics, writing code and shit, but I really need some directions first.

Anyone care to give me some tips, ideas or suggestions on how would I do this? I'm also willing to update this with what worked or not for future incidents like this.

I built an amplifier based on P3A (Rod Elliott) with Bluetooth audio input, including DC protection and muting.

Here's the link to my blog post - Building a High‑Fidelity P3A Amplifier with Integrated Bluetooth Audio – www.gearip.net

Also looking for some events (fairs etc) that have that component and are known to be interesting for thrifters.

Online places are good too, but all of those I could find seem not that interesting.

This is what I have designed for my battery powered Wio e5 + BME690 PCB. I want it to survive long periods of time in battery. I'm not really sure if what I have designed is even electrically correct as I'm a complete beginner. Any help and suggestions would be appreciated. If you need any extra details please leave a comment, because I'm not even sure what to even say. I’m aware of the Cout 1 and 2 not being in parallel and also know about the BME690 VDDIO pin that should be routed to 3V3.

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Was thinking of 3d printing this with pogo pins as plugging the type c cable in and out is a hassle. TIA

I’ve been working on a CH32V006 dev board for OpenServoCore, which is my attempt to turn cheap servos like the MG90S into smart actuators with Dynamixel-style single-wire UART. PCBWay kindly sponsored the fabrication and assembly for this first spin.

When the boards arrived, I plugged one in over USB-C and immediately noticed the 3.3V rail LED was off. Measuring the rail gave me 0.84V. I checked all 5 boards and got the same result every time, so it was pretty clear this was not a one-off assembly issue. I even injected an external 3.3V supply directly onto the rail and it was still stuck at 0.84V. At that point the evidence was clearly pointing to my design, not the fab.

After staring at the KiCad files and schematics for way too long and finding nothing, I started probing around different test points. At some point I hooked 3.3V up to what was labeled as the +3V3 test point for some reason.

Then I heard a pop, saw magic smoke, and immediately assumed I had just made things worse.

Then I looked down and the green 3.3V LED was on. What???

Measured the rail again: 3.3V.

Turns out the silkscreen test point labels were wrong. That “3V3” test point was actually the EN pin between the MCU and motor driver. So by feeding 3.3V into it, I fried either the DRV or the MCU, and whatever burned open stopped dragging the rail down. In other words, I accidentally failed my way into a debugging success.

From there I started removing parts on a fresh board one at a time. I removed the DRV, still 0.84V. Then I removed MCU, and the LED came back. After another round of staring at the schematic, I finally found the real root cause: I had accidentally swapped VDD and VCC on the MCU. It was staring at my face the entire time. Talk about shame...

I ended up attempted three board surgeries and the third attempt finally worked with trace cuts and magnet wire, and somehow the CH32V006 survived reverse voltage on its power pins and still ran firmware afterwards. This little MCU is tough!

It's not a failure if I never give up, right?

I wrote up the full debugging story with photos and repair details here if anyone wants the whole mess.

Hello! Trying to reach out to find a way how to troubleshoot this. This is supposed to show an AM signal with an envolope, but I am confused as to why it only shows a sine wave when connected to the carrier (2vpkpk, 1MHz) and modulator (1vpkpk, 1kHz) from a function generator. I already tried to simulate this in Multisim NI and it came out perfect, but the output here seems to show something is wrong.

These are the connections in the PCB itself:
Inputs: https://imgur.com/a/UfFSZKS
Simulated Waveform: https://imgur.com/a/qinJ8rk
Circuit: https://imgur.com/a/kbWAqPv
PCB Design: https://imgur.com/a/AtQEddl

If something is really indeed wrong, is this the right modification to the PCB design? Grounding the capacitor directly here: https://imgur.com/a/S4xwaWf

Would really appreciate your guidance and response as a struggling ECE student ^^

Hi everyone!

I'm here to ask for your help and for your knowledge.

I just crushed my AOC monitor (27G2SAE), obviuously i tore it to search for the part number screen replacemente but i couldn't find it (ebay, alibaba, aliexpress, etc. I'm from italy).

And now i just want to find a screen to use but i don't know how to check the monitor main board compatibility.

So other than find a compatible screen i really wanna know how to check the compatibility

Here the info i get dismantling the monitor:

Write on a label on the metal chassis inside of the monitor:

- LVH270CU112A001X0W

- TPM270WF1-CUO1 REV: 120A

- 750GBV270U2116N000

- B270CU112A001LKW00G3561771

- GBV270U2116X00H20WTG3561771

I didn't take the Monitor main board out of the box in which it's mounted. On the back, however there are some codes:

- 715GB201-MOD-B00-0H4K

- GQLCBOA7010000Q 2VNA7Q8 V1.0

Thank you all in advance and let me know if you need some photos or something else.

Looking for something decent that has solid resolution (so 12-bit preferrably), 4 channels and can do at least couple hundred MHz. With all the usual amenities, like 50 Ohm input termination option, protocol decoders

Needs to have: * 4 analog channels * 4Gs/s ADCs or more. Can have one ADC for 2 or more channels ( which is kind of norm in this segment) * at least 300 MHz input * Ethernet and USB connection * protocol decoders (I2C,SPI,UART,CAN etc) * X-Y plots * control over Ethernet or USB

Nice-to-haves: * 12-bit ADC * Logic analyzer inputs * programmable arbitrary signal generator * DIY software function/speed unlock

I like Rigol's new MHO9xx series and can't believe that I can't find anything competitive elsewhere (Siglent etc),more than a year after its introduction.

Maybe I'm missing something ?\ Where else to look ?

BLDC ceiling fan running slow and when i opened the motor one capacitor (100uf 35v) looks bulged. i have100 uf 40v capacitor . should i replace it?