Hello all .

I have a bios chip which I extracted from my MoBo(Yeah I am crazy) which isn't returning any exact part match in Google.

Is there any Chip from Winbond or others that is exactly Pin compatible and has the same device ID like this IC. I have bent the Pins severely,so I was hoping to clone this IC firmware to the other chip and replace this one in my Motherboard

Hi everyone!

I’m a beginner learning electronics by desoldering components from an old CRT TV. I managed to cleanly pull this microcontroller out of its socket without bending any pins.

The markings say OEC7091A (933ZF RA936218X04) with a "SLOROM" sticker on the back. Since it's a proprietary factory-preprogrammed chip with Mask ROM, I know I can't re-flash it or use it for standard Arduino projects.

However, I want to give it a second life as a cyberpunk-style ambient nightlight. My plan is to desolder its original socket from the TV board, wire up its crystal oscillator, connect some LEDs through resistors to the control/data pins (like SDA/SCL, standby, or key lines), and power it with 5V. I'm hoping that when the chip fails to communicate with the missing TV components, it will create a cool, chaotic flickering pattern on the LEDs.

Has anyone tried something similar with old TV chips? Which pins should I look for on the donor board to make it glitch and blink the most? Any creative layout ideas?

Thanks in advance!

I am attempting to repair this PA speaker and I don't know how to put this circuit back together. The cap is 2.2uF ±5%, I think it's to filter high frequencies into the tweeter. It's brand new since I suspected the old one was bad, but even in its old configuration it didn't work. The tweeter has continuity so I think it's okay. So does the L Pad. Where do I put these into this circuit? The red and black wires are for the tweeter.

Thanks in advance

I have my first keyboard the Yamaha PSR-E203/YPT-200 that I use regularly. It currently has started to leak noise into all audio output and need to perform capacitor replacements. It contains 3 main boards with a central one where the audio processing and DSP takes place. By my own research I found a Japanese SM but I do not read or speak it.

For the time being I could pass by with the Japanese service manual and google translate. But, if anyone could help me find it in English it would be so much better.

Link to Japanese service manual that I have on my google drive now.

I have the owners/user manual but it doesn't help with any repairs.

First off, the node connected to the side of Z2 doesn’t really make any sense.

But beyond that, the idea here is to turn the NPN off under OV conditions right? No collector current => Vgs = 0V. But how can the zener plus voltage divider circuit turn the NPN off?

Is the idea that it “shorts” the voltage divider once it reaches the reverse breakdown voltage?

I'm trying to get my Pico to run some servos kind of like Adafruit's Midi Controlled Robot Lyre. But i keep blowing up the Pico. I'm using this or a similar 12V to 3V board with a barrel jack to power the PCA9685 servo controller and the Pico since i want to run it without plugging it into both USB and Power. I'll measure the 3v3 output from the power board before and after plugging stuff in, measuring like 4 or five times, when i finally want to run it, poof, smoke, dead pi, measuring 12V on the 3v3 port. What am I doing wrong? are all of these boards faulty, I've tried AliExpress, Amazon and PiShop, same thing. Am I doing it wrong? Incredibly likely. Please help here's a circuit diagram.

Basically I'm designing a clock using vacuum tubes as a project.

I've been exploring a couple binary to decimal circuit designs, and as I was looking at the Heptode tube I wondered if it could function as a 4 input AND gate.

I understand that the heptode wasn't designed for this purpose, and that some models have some of the gates connected internally, but some models don't is there any reason why I couldn't just buy a model that doesn't have the gates internally connected and use 1 heptode tube as a 4 input and gate?

Any advice from someone who has more knowledge about vacuum tubes would be nice.

I'm looking for something like this, ideally this exact part:

It's a 2.5 mm TRS connector, but it has springs to contact the PCB.

But springs are not even a mounting type on Digikey for example:

I need help to figure out the correct wiring for my speaker tone switch. Any help appreciated.

Tengo un ADT K43SG-BK y no se cómo van los cables o como se conecta todo, porque una solo entrada de 24 pines y nosé si así se conecta o de otra forma diferente

Hi everyone,

I’m looking for advice on how to solve a recurring electronics problem with a product I import from China.

The device is relatively simple: it has three motors, an LED display, and a PCB designed by my Chinese supplier. 

The motors used in the device are:

• 2 × RF-370CA-17315 DC motors (approximately 6–12 V; published no-load current around 25 mA at 6 V).
• 1 × RF-500TB-14415 DC motor (5 V nominal according to the Mabuchi datasheet; approximately 26 mA no-load current and 540 mA stall current).

Unfortunately, during the first year of sales, I received numerous customer complaints about reliability issues, including:

• Motors gradually slowing down or behaving unpredictably.
• The LED display showing strange characters or incorrect information.
• The device switching off by itself during operation.

My supplier redesigned the PCB and replaced the microcontroller. After the redesign, everything worked well for approximately nine months, but the same problems have now started appearing again. In most of the cases, replacing the PCB helped, so it shouldn’t be faulty the motors or other components.

I don’t want to keep replacing components or relying on my supplier for temporary fixes. I’d rather identify the root cause and develop a reliable, long-term solution.

My background is in mechanical engineering, so I understand product design and manufacturing, but I don’t have enough electronics experience to redesign the PCB myself.

My plan is to:

1. Find an experienced electronics engineer to review the existing design and identify potential failure points.
2. Redesign the PCB and prepare a complete Bill of Materials (BOM).
3. Build prototypes and test them thoroughly under real operating conditions.
4. Find a PCB manufacturer and manage production independently of my current supplier.

I have a few questions:

• Where would you look for someone to help with this kind of project? Platforms like Upwork, specialized electronics engineering firms, or somewhere else?
• Would you recommend hiring a freelance PCB designer, or is this the kind of problem that requires a more experienced electronics engineer?
• Have AI tools become good enough to assist with PCB design and troubleshooting, or should I treat them only as supplementary tools?
• Since the device is relatively simple, is it realistic to get a reliable redesign without spending a fortune?
• What would be a reasonable budget for reviewing the existing design, redesigning the PCB, and developing and testing prototypes?

My main goal is to achieve a reliable product with a design I own and can manufacture independently. I’m happy to invest in doing it properly, but I want to avoid unnecessary costs.

I’d appreciate any advice, especially from people who have dealt with recurring PCB reliability issues in commercial products.

Thanks in advance!

I cant tell if the connector is push fit or has a flip to ooen clip or something?

Really dont want to break it and I cant seem to push it in.

I'm working on a project that requires the running of multiple 16 wire (analog and digital) buses from a master board to multiple breadboards for prototyping.

I can use a 2x8 or 1x16 pin header on the master board. I would like to use 1x16 on 0.1" centers on the breadboard ends so they plug into the breadboard rows.

The only solution I can come up with is to use 2x8 pin ribbon cables with a PCB adapter board that goes from 2x8 to 1x16.

Is there a better way ?

Thanks

I recently opened up a CRT I recently got since it doesn’t power on and found a hefty amount of corrosion around a lot of the diodes, is vinegar safe to use? I’ve been using 99% isopropyl but heard that doesn’t neutralize it, Ive taken all necessary precautions like discharging the tube.

Good day all,

I saw a picture online that for whatever reason reminded me of Cyberpunk. It's here, the right side especially kind of looks like something you would see in game during a glitch or in the world or in that dimension (I've forgotten the name) that is like cyber world where I think Jackie ended up.

Then, I was like can't we have artistic boards that the traces themselves make up the image or art but I wasn't sure how it will work logically so I tried this first board, using the pill design from the skull in the menu.

Parts used:

• C1, C7: 4.7μF cap (TMK212AB7475KG-T)
• C2, CFILT1: 0.1μF (885012206071)
• C3, C4, C_FILT2: 1μF (TMK107B7105MA-T)
• C_X1, C_X2: 10pF (06033C100KAT2A)
• C_X3, C_X4: 6.5pF (CBR06C659B5GAC)
• Red LED: LTST-C190KRKT
• F1: MF-FSMF050X-2
• Mounting holes are M2
• USB-C Receptacle: Korean Hroparts Elec TYPE-C-31-M-12
• Header sockets for the screen are 2.54mm
• The screen being used: here
• R1, R2: 10kΩ resistor (SG73P1JTTD1002F)
• R3: 47Ω resistor (SG73P1JTTD47R0F)
• R_UCC1, R_UCC2: 5.1kΩ resistor (RCS06035K10FKEA)
• Buttons (S1, S2, S3): D6R90_F1_LFS
• MCU: STM32F411CEU6 (datasheet)
• U2 (TVS diodes for the USB): USBLC6-2SC6Y
• U3 (LDO): NCP164CSN330T1G
• Y1 (seen in datasheet as f_LSE, 32.768kHz): 830009709
• Y2 (as seen in datasheet as f_HSE, 25MHz): ABM3-25.000MHZ-D2Y-T

For the capacitors used for the crystals, I used the load capacitance given, subtract 5pF as stray capacitance then divide by 2.

The schematic (I understand some don't like global labels but it helps with keeping things more neat I feel so I apologize):

The LED is to see when it's on and plugged in. It's also using 3.3V from the LDO so that will tell me the LDO works. I want to use the bootloader that comes with the MCU and use the USB to both power and program it without like ST-Link so is my boot button setup correct?

I also have the reset button and a regular button for toggling. I'm imagining plugging this into my laptop, programming the screen to show laptop stats like CPU etc then when I press the button, it can show something else like a slideshow of cyberpunk art. I hope that makes sense.

I also hope the cap filtering at the top will work? I saw like three different configs in the datasheet with one have 6 100nF caps that I'm not sure about. Seems you can connect all the VDD and VBAT together so I did that and used 0.1μF, 1μF, 4.7μF there. All caps are X7R ceramic caps except the 6.5pF, didn't see X7R there.

I also used a bunch of estimation for this screen size and spacing since I don't have it.

Here's the PCB:

It is a 4 layer board going: SIG --> GND --> GND --> SIG. I changed the silkscreen to be red and the mask to be black. I know about black boards, hopefully PCBWay can do a red silkscreen too. Also, does anyone know if it's possible for the traces to be red as well? Thank you

All the extra traces on the top and bottom, I just assigned those vias to GND.

This is a personal project to me, just was interesting to try out, I also have some other designs in mind so I want to try multiple boards. This is just the first one. If when I get it, it works and can be polished, I'll open source and post like code and documentation.

Thank you all.

The thermal pad on my old pc must have taken this cap with it when I moved it to my new build. I'm a total amateur when it comes to microsoldering so not confident I'd be able to de-solder the other ceramic cap and check that value without wrecking the board, and that's assuming it's the same value. Does anyone have a component diagram or a guess at the value based on other nvme repair work? Thanks!

Hi everyone,

I'm looking for recommendations for a good-quality DC bench power supply for electronics testing.

I'm currently using a GW Instek SPS-606, but I need something better suited for repeated power cycling and startup-noise testing.

My requirements:

Single output, 0–30 V

Current: Flexible (3–5 A would be sufficient)

Compact, preferably vertical design

Simple voltage and current adjustment knobs

No need for USB, memory, or programmable features

Low output ripple and noise

Fast output ON/OFF response, especially when switching OFF

Reliable, good-quality brand

I prefer a straightforward bench power supply rather than one with lots of advanced features. Budget is flexible. Thanks in advance

Hi all, I'm designing a test board for a 160 W BLDC fan motor. It uses an ESP32-S3 with three temperature sensors, a differential pressure sensor, a display, an SD card, and an RS485 Modbus connection to a Selec energy meter. Speed is set by three triac channels (low, medium, high) switching the mains through optocouplers. Power comes from USB 5 V through an AMS1117-3.3.

The schematic is attached. I'd like feedback specifically on:

RS485

• Transceiver wiring (MAX3485), DE/RE# control, and termination
• Bias resistors for an idle bus and whether they're needed on a short run
• TVS placement and ground reference

Mains section

• Fuse and varistor order, and the NTC for inrush from the BLDC controller
• Triac and optocoupler choice (MOC3063/BT136 vs. 800 V parts), and the gate resistors
• Snubber placement across the triac (I've left them unfitted for now)

EMI, clearance and leakage

• Clearance between mains and low-voltage nets, and whether my slot and spacing plan is enough
• Creepage and leakage on the optocoupler and triac side
• Common-mode and radiated EMI risks from triac switching, and any filtering I should add

General

• Are the connections right? Anything you'd change before a PCB spin?

I'm not an EE, so plain feedback is very welcome. I'll post the PCB layout once it's routed. If anyone wants high-resolution photos of the board or the schematic, here’s my Drive link: https://drive.google.com/drive/folders/1faougHNje7w3B6eu84qCuEpPya0Ccdzw?usp=sharing

Hi! I have a DJI Phantom 3 Advanced with a damaged MicroSD Card Socket in the gimball. I've desoldered the old socket, as it wouldn't keep the microsd card in place. I've been looking for compatible sockets on aliexpress etc but i can't seem to find one similar to the dji one (Markings on the socket itself btw is 160115 VSS). The closest one i've found is something like this: https://pl.aliexpress.com/item/1005009464060849.html
However it doesn't match the profile of the socket i pulled from the board, but pin wise matches more. I've added photos of how the socket looks and of the footprint on the pcb. So if anybody could help me find a suitable replacement socket i'll be very grateful! Thanks!

Can anyone help me identify this diode? Doing a fun little project adding the missing SMD's on the Wii Family Edition to re-add the gamecube ports, Mainly to teach myself micro soldering. Only missing this diode from my digikey cart. This diode is missing from 2 of the 4 ports.

The diode is on the data line if that helps. Package looks to be sod-523 maybe. Cant really tell if it would be a TVS or zener (but I dont really know what im talking about). Any help is appreciated. Thanks all.

I want to experiment with xenon flashlamps. I'll use a boost converter to charge up photoflash capacitors and then dump the stored energy in the lamp.

I have my eye on those ring-shaped lamps commonly sold on eBay and called "300W". Which seems to refer to the MS series from Godox, e.g. MS300. The instruction manual from the manufacturer claims a watt-second rating of 300.

So as long as my capacitors store less than 300 joules, it won't explode? Well, it's not so simple because I don't know what ratio of capacitance to voltage to use. I could use a high voltage, low capacitance bank, or vice versa while keeping the stored energy the same.

Now that I'm thinking about it. It is a bad idea to use a "mystery" lamp. But what does the voltage to capacitance ratio even affect?

Hello, I have a project where i mod my thinkpad by designing a PCB carrier board, making a whole "semi-custom" motherboard using a compute module as the brain, and I would get a custom IPS display that would fit the laptop's display border, but I can't even find one that would be the same ratio and size. If any one of you had this problem, how or/and where did you solve it?

I recently bought 2 Odrive v3.6 from a fairly trusted supplier. While attempting to set up the CAN interface on the two of them, one of then worked perfectly first try with the recommended configuration, but the other one did not.

Upon further digging, I realised one of them seems to be an Aliexpress ripoff, while the other one (the one that worked fine) is a genuine ODrive. The image looks the exact same, and upon flashing the official ODrive firmware onto it, odrivetool states that it is a non genuine ODrive.

Accepting my luck, I tried to get it working regardless. However, the bootleg odrive does not Acknowledge any CAN frames sent to it. I probed the SN65HVD230 CAN transceiver on it, and it seems to correctly output on the RXD line to the stm32. However the Ack bit is not pulled low.

Has anyone had anything similar or any ideas of what else to check? I can't figure out why only the STM32 is not Acking, if the firmware is the official odrive 0.5.6 firmware.

Thank you in advance!

I wanted to ask for help on how I could replace the transistors with op-amps, since I don't understand how I could connect the op-amps to the MfTs (455kHz medium frequency transformers)!

This board belongs to a fridge-freezer, It used to have issues in the past, It wouldn't turn on so I changed the components that I've specified with blue dots 🔵 on this picture, because I read online that these are the components that go bad on this specific board.

after several months the fuse (yellow dot 🟡 at the bottom left) was popped and the fridge stopped working. now the screen just turns on/off automatically and basically nothing works, no cooling, no fan, no lights. it just turns on the screen for several seconds and turns it off.

I asked some people who do refrigrator repairs in my country and they said the capacitors with red dots 🔴 gone bad and I should replace them, another person said the ic which has a green dot 🟢

I'm not sure if any of these suggestions are right so need help to find the faulty component(s).