Questions tagged [laptop]

Portable personal computer, normally with a foldable chassis

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33
votes
2answers
58k views

How does a USB C port provide the power to charge laptops?

I've heard about laptops such as the new Chromebooks that are charged via a wall charger that connects to a USB-C port. I'm quite happy that this will supposedly standardize laptop chargers but I'm a ...
22
votes
5answers
9k views

Can FPGA out perform a multi-core PC?

I don't understand how FPGA can be used to accelerate an algorithm. Currently I'm running a time consuming real time algorithm on a quadcore laptop so that four computations can be done in parallel. ...
12
votes
6answers
4k views

Desoldering a tricky DC jack

I'm trying to replace a faulty DC power jack on a laptop, and having quite a difficult time with it. At this point, I'm not sure if the problem is with my equipment, or my technique. Equipment: ...
7
votes
2answers
5k views

Is there a standard I2C/SM bus protocol for laptop battery packs

I'm building a laptop with a custom battery pack. I know that the pack has to communicate through an I2C/SM port on the motherboard, but I don't know how to make the bios/os recognize it. Is there a ...
6
votes
3answers
4k views

Do phone chargers communicate with the phone?

I have come across multiple YT videos (about the new higher USB power delivery and battery degradation) mentioning that chargers communicate with the phone or laptop when charging to avoid battery ...
6
votes
1answer
2k views

Why do laptop batteries have so many terminals?

Why do laptop batteries require so many terminals (upwards of 10 or more!)? Why not just a positive, negative, and a data pin? All the phones I've used only have three terminals, and I would think ...
6
votes
2answers
1k views

Can I clip an antistatic wrist band to an extension cord ground pin plugged into my wall outlet for laptop work? [duplicate]

I've done some small laptop stuff without the wrist strap, but I might replace a logic board of a MacBook and will be working on it for a long time. I have wrist straps and might as well use one. I'm ...
6
votes
2answers
250 views

Headphone Noise from Laptop SMPS

I have been facing an issue that has been a mystery to me for quite some time, and I wanted to see if someone here can potentially give me more insights on this so I can understand why it is happening....
5
votes
6answers
586 views

why do laptops have 10 or 20 volt batteries if most components only use logic level voltages

I've noticed that often laptop chargers and batteries are higher voltages than logic levels, 1 to 5 v. I am building a laptop and was originally using 3.7 v lipo battery. I am curious if I should put ...
4
votes
5answers
2k views

Laptop failure due to constant fluctuation of AC frequency and voltage [closed]

I spend most of time on a boat (not on holiday :/ ) where a huge generator provides electricity. The potential problem is that the output is very dependent of the "mood" of the engine. Sometimes the ...
4
votes
3answers
864 views

Disconnected laptop's internal mic, but sound-card is still picking up sound, why?

I have a HP Mini 5103. A security minded friend wanted me to physically disconnect the internal webcam and stereo mic, no problem as both are individually connected to the motherboard via a wire ...
4
votes
1answer
800 views

Proper way to recover 18650 cells from laptop batteries [closed]

I'm looking for a tutorial on how to recover 18650 cells from laptop battery packs. Like what should I do, and what should I not do, how to test them to see their condition. The way I'm doing it now ...
3
votes
1answer
2k views

Can Computer Motherboards Work Fine Even With A Damaged SMD Capacitor/Resistor?

I'm asking this because when I was replacing my laptop battery, I accidentally hit and broke/disconected one SMD capacitor off the board, then I turned my laptop on, it made some weird electrical ...
3
votes
2answers
2k views

Can I produce a square wave(basically a clock) from a USB port on my Laptop? If yes how?

Can I produce a square wave(basically a clock) from a USB port on my Laptop? If yes how ? Briefly explaining, I am using ad9834 in a project and this chip needs a clock of any frequency ranging ...
3
votes
2answers
1k views

My multimeter probes are too big to measure a laptop battery

I'm having laptop battery problems, and the hardware manual gave diagnostic instructions involving measuring the voltage in the battery. So I bought a multimeter (never used one before in my life) and ...
3
votes
3answers
1k views

Are laptop cells balanced while charging?

I have little-to-no knowledge about how the laptop batteries work. I know there is a microcontroller to actually verify the balancing between cells (and in case blow up a fuse or something similar). ...
3
votes
1answer
407 views

Convert SLA laptop battery to NIMH

I have an old laptop that uses a SLA Battery and I'm wondering what sort of circuit would be need to convert the charging circuit for NiMH Cells. Many manufacturers were able to do some time ago but ...
3
votes
0answers
56 views

Need help identifying the 4 microphone wires in my laptop webcam

I am trying to adapt my laptop's webcam into a USB webcam. Although I couldn't find any schematics online, the manufacturer did print (I assume) labels to identify the 8 wires coming out of the webcam....
3
votes
1answer
99 views

Will this DC UPS with off the shelf components for home network and laptop work?

I am trying to build a DC UPS to power modem, router which have power requirements of 12V 2A and a laptop which has power requirement of a 20V 3.5A. I am planning to use a AC to DC SMPS which is ...
3
votes
0answers
306 views

Offical Name of Dell/HP Common Laptop Power Jack/Plug [duplicate]

I have seen this question asked before, but never has it gotten a real answer. With the popularity of this plug I find it hard to believe it does not have a standard name or IEC name. Does anyone ...
3
votes
2answers
239 views

How does a laptop maintain battery at full?

I know how a laptop battery becomes charged, however, I am not so sure how the power is maintained when when the battery has been charged to the maximum. I am unsure whether the laptop would switch ...
2
votes
4answers
575 views

Using different 18650 to repair laptop battery

Background: I have a laptop with a bad battery. Upon opening it up and testing the six 18650 cells that make up the battery, I found one to be completely discharged while the other five were still at ...
2
votes
2answers
2k views

Is it possible to convert 19.5V 3.33A to 12V 5.5A?

I have a laptop charger which has 19.5 V 3.33 A output. I want to use it for raspberry, which needs 5V and 2.5A and for monitor which needs 12V 3A. Is that charger strong enough to run the whole ...
2
votes
2answers
1k views

laptop battery connector name [closed]

I want to know what is the name or family name of the laptops' battery connectors? I want to replace a broken connector but don't know what to search for on digikey/mouser. Image of connector below: ...
2
votes
1answer
1k views

Why are input MOSFETs in Laptop power supply always in pairs?

For example, on https://youtu.be/CW87dyYIimE?t=340 (and related work on motherboard), it says the managment chip uses two MOSFETs as a switch (as overheat protection, emergency poweroff on 10-second ...
2
votes
2answers
4k views

18650 Li-ion cells for the laptop battery: with protection circuit or not?

My laptop battery died and I've took it apart to replace the cells inside. Do I have to buy new cells with protection circuit or without it? Googling the existing cells part number LGABC11865, I've ...
2
votes
1answer
1k views

Hacking Dell charger to run directly from an external 19.5V power source [closed]

I needed to power my Dell laptop without having 220V (because my inverter is burnt in the middle of nowhere) in my van. By using a boost converter that can deliver the required power, I simply set the ...
2
votes
2answers
85 views

20V laptop power supply from four 5V+5A 'baby' supplies

I've got an old gaming laptop which comes with a very annoyingly big brick PSU, rated at 100W and 20V. I do not care that the PSU is heavy, but it has a weird form factor, and I always have to drag ...
2
votes
2answers
407 views

What is this black tape on my laptop's keyboard?

I am trying to replace the keyboard on my 2019 Samsung Notebook 9 Pro. I had to pull off a layer of black tape on the old one to get it out. The tape was glued to the bottom of the keyboard, right ...
2
votes
3answers
146 views

Pulling analog DC output from a laptop

I am using a laser source that can accept analog input (0-5 V) to set light intensity levels. The input impedance of this driving voltage is 50 Ohms. Typically this is connected to a function ...
2
votes
2answers
943 views

Grounding a laptop through the DC-jack?

I would like to reach zero potential difference between me and my laptop (to avoid ESD) before opening the back cover. I'll connect my wrist strap to a common ground point, thru a resistorized coil ...
2
votes
1answer
108 views

What models and brands can I find for logic fuses?

I'm trying to find logic fuses like the ones found here. As I'm new user, I couldn't comment there, so I created this new question. That fuse, in my case, is on a Clevo P170EM battery. This battery ...
2
votes
2answers
2k views

Does a sound card low pass filter input?

I ask this question just because I'm curious to find out. As far as I understand, the Nyquist theorem says that the sampling frequency must be at least twice the bandwidth of the signal to be sampled....
2
votes
1answer
187 views

Can I replace the original laptop battery with an OEM battery with higher voltage / power?

My original laptop battery is 11.1V and 74 Wh. It was starting to swell and needed replacement, but I bought accidentally bought a wrong OEM battery that is 11.4v and 71 Wh. Is it safe to proceed and ...
2
votes
1answer
2k views

Function of the Third Pin Inside Laptop Barrel Connector

So I've been doing research on barrel pin connectors, and have been trying to apply this knowledge to understand laptop barrel connectors, specifically. My confusion relates to the function of the ...
2
votes
2answers
1k views

Replacing cells in laptop battery

I successfully opened the battery of my laptop without damaging the case, and now, I want to replace the worn out batteries (2600mAh) with more powerful ones (3200mAh). I know the risks of working ...
2
votes
1answer
4k views

Alternative to lead-acid battery on power wheel toy

This might be a silly question, but here I go. My son’s power wheels car battery (12v 9.5Ah lead acid) is gone and, here in Venezuela, they are pretty difficult to find, not to mention the high prices....
1
vote
2answers
517 views

Recommendations for building a dedicated external speaker from an older computer

I'm super excited to jump in and learn more about building an external stereo speaker from an older salvaged macbook laptop. I loved using the laptop to reference how my music sounded to get a better ...
1
vote
1answer
2k views

What protection circuits do laptop batteries come with?

I am currently using an old lithium-ion laptop battery pack for my portable sound system. The battery seems to work pretty well for its age. I simply hooked up a cable to the positive and negative ...
1
vote
4answers
183 views

Why aren't there electric cars with solar cells built on top of them? [closed]

I think it would be nice if leaving the car outside on a sunny day would charge up the batteries. It would make possible long-range weekend trips to the countryside because during the 2-3 days of ...
1
vote
3answers
7k views

Hacking laptop power button: Turn on laptop when AC's back

I'm using one of my old laptops as a server. I'm running the laptop without battery in case of a need for a hard reset. When I need a hard reset, I want to be able make this happen with a toggle of AC ...
1
vote
1answer
68k views

LVDS 30 pin cable confusion [closed]

I'm trying to save a LG LM270WQ1 from a imac 2010(?) I want to order an MT6820-B rev.3 universal LVDS driver, or kinda (because the one that is suggested for this screen is very expensive driver ...
1
vote
4answers
136 views

Which capacity measurement is the correct way to measure?

So I've seen batteries showing their capacity in mAh and I've seen others showing in Wh. Phone batteries are always measured in mAh, while for some reason BatteryInfoViewer on my computer only shows ...
1
vote
1answer
194 views

I took a old webcam from a laptop and connected it over usb, it does not work [closed]

The camera has 5 pins: 5v, D-, D+, GND and powerC. I dont know where to plug power c in. Can someone help me please, the camera is CNF9138_A1 By Chicony
1
vote
1answer
154 views

Why are laptop computers usually powered around 20V DC? [duplicate]

Most electronic devices use 3.3V, 5V (all USB devices), 9V or 12V (very often for electronic music gear), and we usually all have dozains of such wall adapters at home. Even desktop computers have ...
1
vote
1answer
114 views

Can someone help me establishing the polarity of this dc jack on my laptop motherboard?

So my laptop charger port is fried and I wanted to establish the polarity of the points on the board so I can solder a off the shelf jack instead of the original one which is not available anymore. I ...
1
vote
2answers
620 views

Charging a USB C device with fixed voltage / No Power Delivery/ Fixed dedicated Source

I have a lenovo yoga 730 13-ikb without a charger, it uses TYPE C usb charger with PD specifications for the charger in online stores are: AC Input: 100-240V ~ 1.5A 50-60Hz DC Output: 20V 3.25A (65 ...
1
vote
2answers
570 views

Lenovo Y580 battery - Panasonic NCR18650b MH12210

I am new to the group, so thank you for this great community. I am a student and "DIYer" and like to repair simple electronics. Anyway, so here is my situation: Want to repair my laptop battery as ...
1
vote
2answers
327 views

Charging multiple laptop batteries

I want to build me an electric longboard, and I was planning to run it off of 4 or 5 11.1 volt laptop batteries... I want to wire them in parallel (The sets of 11.1 volt), and charge it as one big ...
1
vote
2answers
213 views

Grounding of IT equipment for office ESD protection

We've been having a lot of problems in my office with ESD. People touch cubicle frames and monitors shut off momentarily, painful shocks through laptops, etc. I'm worried about equipment getting ...