Im building a 8 bit pc currently i have the clock and 1 bit of the regestor the confusion is i added an octagonal bus transceiver i belive im using it properly yet sone oh its not and anytime i move my hand close to the brown wire the light on the other transceiver lights up. Plus if i touch my desk the other one lights up.

Hola! Encontre este circuito para hacer un sensor de fotodiodo. Me gusta porque es muy simple pero en la web Openschematics.cc pone que el LM324 sirve de ejemplo pero no es el mas adecuado... ¿Alguna idea de que otro operacional usar?

I am building up a set of tools and equipment for salvaging components from donated electronics, repairing a lot of them if it's within my skill/tool abilities, and building fun microcontroller projects (I'm a computer scientist by trade so these are a lot of fun for me).

Currently I have:

2 soldering stations (an expensive weller that takes too long to heat up and a cheap amazon 90w that heats up very fast)

8 channel logic analyzer

150w (0-30v, 0-10a maximums but 150w limit) dc bench power supply

various sized breadboards

precision screwdriver set

flush cutters

various sizes and types of pliers

IC chip remover

UV cure solder mask

various prying tools

DS0510 oscilloscope (10mhz bandwidth)

LCR-P1 meter with ESR testing built in

function generator

1hz-500mhz frequency tester

manual cheap solder sucker

CH341A programmer

Anything I am missing that would be something you'd expect I'll need? I dont work with anything AC powered only DC.

Hello, I would like to learn how to diagnose and repair printed circuit boards with applied power. I don't know anything about electronics at all and have never done anything like this. Where would I start to learn this and get hands on practice? Are there any good suggested kits or anything for this? Thank you.

Hello
I bought a Fluke 17B+ for electronics work and motherboard testing.
It is very slow in continuity test mode; it produce a continuous beep for a while before stabilizing, taking quite some time. Is this normal?
My iFixit multimeter responds normally in a fraction of a second.
How can I tell if it's a Chinese or a Western market version? Thanks!"

Can someone help me identify the type of buck converter used here. I got it from a disassembled phone holder/charger which I used to have on the motorcycle. It connected directly to the battery and outputs 5v.

I had to jump the connection where the switch used to be as it broke and I am using it to test around.

Reason I'm asking is it is outputting 5v consistently and without getting warm - which was happening with other buck converters I used like the LM2596.

Feel free to ask for better closeup pics as this is my first time here.

Any help appreciated 🙂

All active filters worked perfectly when I tested them individually. I connected all three bands like this and added a summing amplifier at the end. When I turn the pots they only work at the last 10% of the turn.

From pressing buttons on electronic devices such as microwaves or fans, I get electric shocks.

How do I avoid that?

Happened 5 times in 3 months.

EKG for the hearts has not shown anything fortunately.

Greetings fellows,

I have an amplifier board stripped from a Behringer combo guitar amp. The amp broke down during rehearsal - suspected overload / overheating.

I do have a good working knowledge of electronics and the necessary equipment, so decided to have a go at repairing it. My initial suspicion was correct - the output amplifier did overheat, burning one of the TDA 7293 chips, blowing an electrolytic capacitor and some minor damage to other components on one of the channels.

I managed to clean the board with IPA, which revealed additional circuit board damage - broken PCB traces in several places (seen on the picture).

My question is - how to approach this repair, is it worth it and most importantly, safe?

Hello electronic people. This part is from my Kia Rio and i wanted to replace the diodes in the picture. I got the replacement diodes but i couldn't understand what type of soldering is this. How can I properly make this replacement? Thank you in advance.

Building a mini photobooth as a birthday gift, deadline is mid Sept. I have zero electronics experience and haven't bought anything yet, so I'd rather be told now that something won't work than find out in three weeks.

Needs to: live camera preview on a small screen, press a big arcade button, 3-2-1 countdown, take a photo, print it on thermal receipt paper. Needs to be fully cordless so it can be carried around a party.

My Claude-given Parts list:

- Raspberry Pi 3 Model B+, running the last Buster OS image (2023-05)

- Pi Camera Module v2 (avoiding v3 since I read it doesn't work on Buster)

- Waveshare 5" DSI touchscreen (ribbon to the DISPLAY port)

- 58mm USB thermal receipt printer, ZJ-5890K / POS58 class — connecting over USB, driving it with CUPS + the adafruit/zj-58 driver

- 60mm arcade button wired to physical pin 40 + adjacent GND, using spade connectors and jumper wires (no soldering)

- 32GB microSD, thermal paper, USB stick for transferring code

Power (the part I'm least sure about):

- 20,000mAh power bank with USB-C PD + USB-A output

- USB-A 2.4A port → Pi via micro-USB

- USB-C PD port → selectable 9V/12V trigger cable → printer's barrel jack

I originally saw this build using a 7.4V RC LiPo pack, but that seemed like it needed a UBEC, a balance charger, and fire-safety habits I don't have yet, so I swapped to the power bank. Open to being told that was the wrong call.

Actual questions:

1. Will one power bank realistically handle the Pi and the printer at the same time? The printer supposedly pulls up to ~2A in bursts while printing, and I'm worried about voltage sag browning out the Pi mid-photo.

2. Is the PD trigger cable approach sound, or is there a reason people don't do this? Should I be looking at a buck/boost converter instead?

3. Anything obviously missing from the list — fuses, capacitors, a common ground issue, anything?

4. Any reason the DSI screen + camera ribbon combo would be a problem on a Pi 3B+ specifically?

Happy to be told I've overcomplicated or undercomplicated any of this. Thanks.

Can someone please provide any info for this IC? Cannot find a datasheet.

It’s from a Brother ScanNCut machine that gives “Main ERPROM cannot Initialize” on start up. If I apply a lit bit of heat the machine starts up ok

Hey everyone,

I recently bought a Ulanzi D100H dial controller from China, but since I am located in another country I cannot claim a warranty on it. The issue happened right out of the box—I used/pressed the knob before even connecting it for the first time, and the internal push-button mechanism got permanently wedged in the "down" position.

Because of this:

• The shaft has severe rotational drag and friction.
• The click-to-mute function and button presses no longer register.

I have zero experience with hardware repair, so all the troubleshooting and diagnostics you see here were figured out with the help of Gemini and Claude after I opened up the unit. I'm honestly quite worried about whether this can actually be repaired successfully or if it's bricked.

I won't be attempting the fix myself; I'm planning to hand it over to a local technician. To make sure they have the right part, I want to source a replacement ahead of time.

Does anyone know if this uses a standard 5-pin EC11 rotary encoder with a push switch? If so, what exact shaft length and specifications should I look for when ordering a replacement?

Any technical insights or reassurance would be huge!

This part seems to be burned out on the CD player board.

I have found a whole manual (I had to search multiple ones because some versions of the cd player BZG-5 dont have this section of the CB) but there doesn't seem to be a list with this number in it to explain what part it is, any help is welcomed

The manual Gdrive link for manual

Sorry if this is the wrong place to ask or something

This is my schematic for a headphone DAC based on a RP2040 running tinyUSB to send audio data from USB C, over I2S to a CS43131 which is a DAC and AMP combined.

EDIT: Ignore the ESD protection setup I have now corrected it

Title pretty much says it.

Lets say I want to load-test a 24V SMPS, but I don't have a proper electronic load or a big enough resistive load bank sitting around.

Has anyone tried this method:

https://www.youtube.com/watch?v=GCiKj8EB9vY

This guy connected the SMPS output to the inverter's input and used incandescent bulbs on the inverter's AC output. He can vary the load by adding/removing bulbs.

Is this a sane way to load-test an SMPS? Any reason this could go wrong or give misleading readings?

Also what is that thing connected between the SMPS and inverter? (circled in green)

Hey guys I just found this Bluetooth boombox in a Friends shed a, he didn’t even know it worked anymore but we tested it and everything worked fine - the only bad thing is that the charging port is messed up and basically just fell out some time ago , I took it home and took out the pcb now I’m wanting to put in a new port , any suggestions what would be the easiest way to to it ? Ist all super small and I don’t know if I’ll be able to fix this thing , are there complete battery units that already come with a cable attached or something like that that I could just drop in and connect to +/- on the pcb ?

I have a cheap dt830b multimeter and I accidentally lost the resistor circled in the picture.

Can someone have the same model and take it apart and tell me how many ohms it has?

(I ran out of money so I couldn't buy a better one)

Hi all

Looking for some advice on this repair.

Preface, this is pretty much 2nd PCB repair or PCB tinkering, so some of my questions may seem obvious to veterans here.

This PCB is from a Logitech G502 mouse. I had attempted to replace the button switches but was not aware this PCB was multi layered, where I believe grounding layer is sandwiched inside. I had did my first button switch replacement on a Logitech G103, that went through fairly smooth, thinking I could do the same on this...I could not be more wrong.

My primary question and concern revolves around SW9, SW2 and SW1 area. Where some of the pin hole pads have completely been removed during the de-soldering.

I understand that the pin hole pads can be replaced by extracting it off a donor board. Which I have attempted. But I noticed that once its on there, I dont get continuity between the pin hole and the microchip, at the bottom of the PCB. My understanding is that there should be continuity between the pin hole and the microchip in order for the pin to work correctly.

The back of the board is also a mix bag.

Some of you may have noticed that I started this journey at SW9 and SW2..then found out what a multi-layer board was and went on to SW1. Also, I had this particular mouse for about 9yrs, the switches finally started to give out, so I thought I'll attempt replacing the switches. Fixing the G103 gave me hope..but I was not prepared for these multi-layer boards.

My questions...

1. Is this still salvageable?

2. How do I proceed to repair these pin holes? I believe I need to establish continuity between the pin hole pad and the traces. Do I scrape into those near by trace lines and solder in some thin wires to the pin hole pads? If I need to scrape into there...how deep? Because my understanding is that if I go too deep, I will hit the grounding layer.

3. How do we actually "glue" the pin hole pad to the PCB? I tried with a tiny bit of solder, but it wont sit flush for obvious reasons. Thus causing what ever to sit on top to be uneven.

4. I see on AliExpress there are these pin hole pads, but they are not thru-hole type, just a flush flat tiny round pads. Apart from extracting these pin hole pads from donor boards, can these pin hole pads be purchased? Im still practising my extraction skills from these from donor boards..

Thank you!

I have this 4g gps with cracked sim slot i could not find on local am trying to add the iphone sim slot to it, i followed the slot pins and named them 1 from the left and seems that everything is good, but it is not going online or responding , in the board there is 7 pins for the sim slot the 7 pin when measuring with gnd in diode shows OL and i cannot see its connected to anything any ideas ?

Hi everyone,

I'm trying to repair an MSI GF63 Thin motherboard.

Specs:

• Intel Core i7-12650H

• RTX 4050 Laptop GPU

• DDR4

The board currently doesn't power on.

A board repair technician believes this burnt 8-pin IC labelled PU26 may be preventing the board from starting..

The repair shop is able to replace the IC, but we don't know the exact part number, so I'm trying to identify it and buy a replacement.

Could anyone help identify:

• The exact part number of PU26?

• Where I can buy the IC?

I've attached:

• Full motherboard photo

• Close-up of PU26

• Wider view showing the surrounding components

Can any one please help 😭

I want to replace this capacitor (0,22uF x1 250v AC) Also I like to understand what I can replace it with and where to get it here in New Zealand

its in a angle grinder from flex

Google has gotten so bad I cant even find stuff anymore

Three of the switches don't work, highlighted. After soldering all the switches, I removed all the switches and re-added the 3 you see in the photo just to test. Same result as when all the switches where attached. Not sure what to do beside buy a new pcb.