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Questions tagged [reverse-engineering]

The process of taking a completed system and determining details of its design; may have legal limitations or ramifications in different jurisdictions

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22 views

Samsung mobile LCD reverse engineering [on hold]

I salvaged a LCD display from an old Samsung. It's from GT-s3310. I can't find any datasheet on internet. There are few things I managed to find out. NUMBERINGS AND MARKINGS The display says it's ...
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69 views

How does this circuit work? Capacitive DC supply from 230VAC - Radiator control board

An electrical house radiator stop heating, so I opened it and start trying to understand how the control board is working. I was very surprised to discover a very very low cost board with a ...
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1answer
75 views

When checking for continuity between two points on a PCB, how do I know it's not going through an inductor?

When trying to debug a non-working circuit on a PCB, it can be difficult to trace the circuit flow visually, as described in the answer to this excellent and related question: How can I reverse ...
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75 views

Looking for a way to re-program 16x2 LCD display EEPROM font

Some time ago I've seen this topic - asking where does the fonts stored in 16x2 (1602) LCD display. Does a 16x2 LCD display has its own EEPROM? I'm really interested in this, and didn't find any ...
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42 views

Voltage divider in parallel with DC motor driven by H-Bridge: can someone explain me this circuit?

I have a battery powered device with a PCB wich control a small DC motor (3V). With a little bit of "reverse engineering" I darw this schematic: So there's an 8-bit IC (STM8L052C6) that drive the ...
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33 views

Executing a page read

I am working for a few months on dumping the content of a certain NAND Flash. This is the first time that I am doing this so I needed some time to get a good idea of how this works. The NAND Flash ...
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2answers
70 views

Determining motor position with EMI

I would like to determine the position of a motor based on its radio emissions, I do not have access to said motor but I am trying to reverse engineer it. Here is what I know about it : It has X ...
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1answer
124 views

I need help to understand a sniffer circuit schematic

I'm an electrical engineering students and for a school project I need to understand a circuit schematic. First, I will provide some context. The school project I'm working on is the modification of a ...
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1answer
108 views

Retro 80s computer keyboard broken

I currently have project trying to recover a 1980s homebuild CP/M computer. Mostly everything is working, except the keyboard. I have trouble identifying how it's working as there is neither an ...
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1answer
85 views

Reverse engineering and reimplementing a garden hose water timer

I bought a cheap chinesse water timer with the idea of reimplementing the electronics to add Lora Radio managment so I can turn or or off the valve from a large distance and all running on batteries. ...
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1answer
98 views

What does this circuit do? Reed switch debounce?

I'm trying to reverse engineer a pcb and I'm stuck on this circuit. I believe the capacitors maybe for debounce. The switch is a reed switch. Can anyone shed any light on it?
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91 views

Reverse-engineering RS485/Mechatrolink-II front-end design

I'm trying to reverse-engineer Mechatrolink-II front-end circuitry. Its physical layer is simple RS485 (with isolation transformer) running at ~10Mbps. Here is the schematic I obtained from the PCB of ...
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1answer
82 views

How to decipher hex code for time data on an older serial port device

I’m using an old Draeger PAC III sensor to measure gas concentrations, with the goal of remotely transmitting the data via Arduino. Accordingly, I cannot use the proprietary software to output the ...
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1answer
96 views

Un-moving “static” image from VGA controller

I am reverse-engineering a daughter card which uses a ADV7125KSTZ140 VGA video DAC driven by a FPGA. The FPGA is a Xilinx Spartan 3E programmed by an off-board processor using slave-serial mode, ...
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2answers
74 views

How to proceed to draw the circuit diagram of an unknown circuit?

I have some old devices like SMPS power supplies, and I would like to analyze their workings by first drawing a circuit diagram of them. I'm looking for some tips/techniques for doing this. Should I ...
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1answer
149 views

Help identify IC with erased label by using pin connections in the schematic

I am reversing a board which some of its IC labels are erased by the manufacturer. I've drowned its schematic in the picture below. The label-removed ICs in the schematic are IC5, IC8, and IC13 which ...
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1answer
37 views

Find ROM and RAM in .bin file for micro controller

I use the Arduino IDE to compile some code to a 32-bit ARM Cortex-M3 based microcontroller. The result of the compilation is <...
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52 views

Need help to identify SMD diode with marking code 3W28J

I am trying to reverse-engineer a PCB, but I can't identify an SMD diode with marking code 3W28J (image below). Can someone help me to identify the component?
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52 views

Reverse engineering LCD signals on HP power supply

I have recently acquired an HP 6632A power supply and was inspired by Roberto Barrios' project of replacing the screen with an OLED display to do the same. However, it is evident that the 6632A is ...
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1answer
50 views

Easy way to probe signals on a multi-conductor cable?

I have a device that I need to reverse-engineer. This device has a large multi-conductor cable -- over 20 wires that are jacketed into two circular bundles. I'll need to look at all these signals with ...
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3answers
8k views

Odd PCB Layout for Voltage Regulator

I am reverse-engineering a board which has a Xilinx Spartan 3E FPGA, with VCCAUX powered by a 2.5 volt regulator. Below is the PCB layout for the regulator part of the circuit, and something seems ...
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25 views

Pin config for CIS scanner

I've salvaged a linear scanner from an HP scanner cum printer. The scanner senor model is CA4B94. It's got two portions on a single flat ribbon cable. One is for the motor, so I guess it's safe to ...
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43 views

Figuring out Inductance

I am trying to figure out the Inductance used on this PCB. I know it's value but need to understand what type of inductor it is and other things so I can order it. The code on it ...
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129 views

How can i identify these chips

I have a board that has 4 chips that have their markings being removed. I'm not able to identify them. I'm looking for a way to identify them. I have actually two different boards made in different ...
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6answers
7k views

Is it truly impossible to tell what a CPU is doing? [closed]

Computer programmers often recite the mantra that x86 instructions are totally opaque: Intel tells us they are doing something, but there is no hope that anyone can verify what's happening, so if the ...
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1answer
83 views

Detect an unknown communication protocol and read data on it

We have old type textile machinery in our factory. (open end machine) on the machine's screen is showing the operating efficiency of the machine. Under the hood, When I follow the cables, the sensors ...
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26 views

Naming confusion, how to connect DAC (BB/TI PCM1603KY) I2S, which pins do I need to use?

I am totally new in the field of DAC's and I2S. I salvaged this board from a DVD player and is well documented. There are three data lines DATA1..DATA3 that will be used for ...
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100 views

Help identify RJ11 pins on a relay board - No152133

I'm tinkering with my garage door motor (Marantec Comfort 220) which have a RJ11 6-pin connector (X10) for an accessory relay board. The board consists of three (3) relays driven via the RJ11 ...
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1answer
183 views

Reverse-engineering RS-485 communication

I've been trying to reverse engineer the communications protocol used by my home domotics, which I was able to determine uses a RS-485 implementation. I'm using a USB RS-485 serial dongle and an ...
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3answers
109 views

solder-bridge at ribbon-connector?

I am currently trying to repair a pen-tablet-monitor, which has what i call a 'blind/dead row'. Meaning that i can draw everywhere, but there is this one row, where any input is either picked up by a ...
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46 views

Strange CLK-similar signal

I'm reverse-engineering the data bus inside a projection clock to find out how to drive the projection without the clock. I use PulseView with a logic analyzer. What I (think to) know so far: It ...
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1answer
45 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 ...
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30 views

Wiring video inputs for the Microvision Showwx+ projector

I have been given a Microvision Showwx+ projector which I would like to hook up to a video source. Mine only came with the Dock connector, so it will not work with any modern video outputs. I know ...
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1answer
58 views

Reverse Engineer DIN 5-pin connector

Summary I have a digitial guitar amplifier that can be controlled via a footswitch. The footswitch is connected to the amplifier via a DIN 5-pin cable. I want to be able to control the amplifier with ...
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38 views

Speaker crossover: can wrong ESR cause amplifier to clip?

I have an old pair of speaker I decided to revive. I recapped the crossover with new caps but now my amp keeps clipping when I turn the volume a little bit high (and it was not before). I wonder if ...
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2answers
145 views

Reverse engineering SREC firmware

I have a firmware from a long discontinued product that I would like to improve on. The firmware is in a .mot file format (SREC from my research) and is uploaded using a tool called M16C asynchronous ...
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1answer
141 views

Please help me understand this bjt set up works

This is part of an automotive timer (NOT a 555!) that we have at work. Because I'm extremely bored I'm challenging myself to understand how this one operates. I've spent about 1.5 weeks with tutorials,...
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1answer
271 views

Help me hack my Yamaha Receiver

I’ve been given a faulty Yamaha RX-V765 Receiver. Parts are no longer available for this unit, and I’m trying to convert (i.e. hack) it directly into a Power Amp. I have been able to get some audio ...
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70 views

How should I go about reverse-engineering this printhead?

I'm interested in using the Epson FA04010 printhead in a project. I'm pretty sure it uses piezo-based inkjet tech, and I can see in the product images it has 21 pins. I can't find any specs at all for ...
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2answers
58 views

Bosch Glue Pen: Bypassing automatic timeout [closed]

I have this Bosch hot glue pen. It has an annoying habit of turning itself off. I guess it's probably intended to be a safety feature or a battery saver, but really it's just a nuisance. Can I modify ...
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2answers
51 views

Primary current expectation in unloaded toroidal transformer

Background I found a hefty, 7 kg toroidal transformer in visually good condition at a flea market which I am trying to map out. This is part one: I am not sure about what is happening on the primary ...
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75 views

Where to get datasheets for this part: ZJL JL2233 1650M18 ?

I am currently reverse engineering an LED Driver (STARES LED DRIVER; Model No.: WLJ-60-50) for my LED Lamp where the lamp doesn't turn on anymore. The trouble I have with this PCB is that i can't ...
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1answer
167 views

Identify this open collector serial protcol

I'm trying to analyze the serial link between two devices, respectively a motor controller board and a Li-Po battery manager, which battery powers both devices. The application is a battery-powered ...
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1answer
99 views

What's the purpose of this circuit section?

I'm experimenting on VCA circuits and found the same (or similar) pattern in many linear VCA projects found in internet using LM13700 OTA. The specific section I'm curious is made by an Op-amp, a ...
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1answer
58 views

Does tools for automation analysis image IC for extract netlist exist? [closed]

Does tools for automation analysis image decapsulated IC for extract netlist exist ?
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1answer
742 views

How does this circuit work? 48VDC relay and 1.4VDC battery from 230VAC

In order to repair a programmable timer plug, I'm doing some "reverse engineering" on it, it's not for the cost (about $5) but more for learning and recycle thought. I draw the scheme but can't ...
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3answers
3k views

What is this small unconnected solder blob on this PCB?

There's a small solder blob in the middle of this one-sided PCB (a switch-mode power supply), surrounded by unmasked board. The blob is 1.5mm in diameter, and the non-masked area is 4mm in diameter. ...
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1answer
83 views

What program would be appropriate for designing a reimplementation of the TurboGrafX16 at gate level?

To be clear, I'm looking for a program I could use to redesign the TurboGrafX hardware at gate level, but to gate to gate, just for functionality. Also, given that I'm interested in GPU design, what ...
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3answers
297 views

How to interface with micro LCD projector?

I disassembled a cheap "wall projection" clock: And removed the LCD board that displays the projected clock readout in front of the super bright red LED: As a small hobby project, I'd like to wire ...
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2answers
124 views

What software use to hack wireless protocol ( logic analyze ) USBee

Q: What software do you use for logic analyze? Why: I try to hack(reverse engineering) my home wireless heating system control to make my own central control unit. Wireless: My heating system uses ...