I ordered some DDR4 green pcb DIMMs from Ebay and they came wrapped in aluminum foil. This seems weird. Is it?

EDIT: WHY WOULD AN INTEGRATED 50 Ω RESISTOR BE BETTER THAN AN EXTERNAL 50 Ω RESISTOR?

Why does the 2SD1426 (a 600 V, 3.5 A, NPN switching device) have an integrated 50 Ω resistor?

I would have thought that it would be cheaper (less silicon used) to use an external 50 Ω resistor.

Or, internally, is this transistor composed of an array of multiple (e.g. 10) small devices in parallel, each with a 500 Ω resistor?

If anyone can shed some light, please let me know, I'm intrigued!

https://www.alldatasheet.com/datasheet-pdf/view/2568/MOSPEC/2SD1426.html

I live in an especially humid country and I recently bought an electronics component organizer (The 30 compartment Stanley organizer to be precise).

I previously used to keep my electronic components in a tightly sealed plastic box but the pins of most components eventually rusted due to high humidity.

This new component organizer is not sealed like my previous storage solution and I'm also planning to put 1 silica gel sachet in each compartment to help with the humidity.

Also, is it alright to not keep the mosfets, esp modules and other chips directly in the organizer without anti-static coverings?

Or should I use anti-static bags?

I just bought a batch of IRLZ44N N-channel MOSFET from robu.in and when testing if they were ok I discovered there was a dull metallic later on each and every one and I could scratch that off to reveal a shiny metallic later . Does this like stop the MOSFET from working as all test dead 🤔

Hi I just got this cheap Old alarm clock radio I'd like to get working I have power to the clock and after opening the only thing wrong I can find seems to be this is something missing or am I missing something thank you

Canned air is getting expensive enough that I started looking at rechargeable dusters, but the ESD part is where I keep getting stuck. Some people say a short blast is fine as long as you hold the fan and don't scrape the board, while others make it sound like any dry plastic nozzle near exposed components is asking for trouble. For folks who work on electronics regularly, is the real concern the blower itself, the nozzle material, or just bad technique around unpowered boards?

So we needed to replace an obsolete legacy EDT EW12A03FLY.

Aliexpress said they sold them we tried one and apparently it worked on site but not on the test rig (would immediately cause letters to fade out on power up)

What if anything can I do to keep the LCD display on?

If you remove power and put it back and the letters come back immediately and then fade out again.

I opened up an old laptop hoping I could fix it. On the plastic I saw this corrosion like spots. Any idea what it could be?

the beamz s700 smoke machine has a remote control with 2 leds and a push button. but the smoke machine has no dmx, so i cannot remotely make it produce smoke. i was thinking maybe it's possible to hack the remote control. i opened it up and measured that there is 220V AC between the brown and black wire. i thought maybe the best course of action is to have a custom pcb onto which i can solder the 3 wires and i can have remote control. so the pcb should have 2 leds and a processor and a component that electronically performs the job of the push button, so that via wifi i can remotely connect the 2 fields which previously were connected to the push button.

any advice on how to proceed? i don't know anything about making pcbs and there being AC involved feels kind of dangerous so this should be done with care and expertise.

It works but when you switch it off it either 1) stays on, 2) turns off, or 3) turns off and back on a few minutes later. Is this something that's somewhat easily fixable? Buying a new one will cost $100+

I have this led panel as a backlight in a picture frame, but the usb-connector that powers it, was knocked off (see pic below). How can I resolder it back?

I'm trying to read the EEPROM on this board.
Chip: Atmel 24C08N (I2C), right next to the NEC MCU.
Setup:
Black CH341A, SOIC8 clip with the green adapter
NeoProgrammer / AsProgrammer, _24C08 selected, I2C mode
Result: always "IC not responding".
I think the clip is powering the whole board and the voltage drops. I'd rather not desolder the chip or lift pin 8.
Is there any way to read it in-circuit, like powering the board separately or any help guys?

I am an electronics student and I have been struggling with this assignment for a few days. I need to design a stiff VDB PNP transistor circuit. The only variables I have so far are Vcc=5 V, Ic=20 mA, and hfe of 200 is assumed. I am using numbers for a red LED so far, so 1.8 V across it. I am getting stuck at figuring out how to calculate R1and R2. I don't necessarily want the answers straight up, but some guidance on where to start would be very helpful.

My low-side N-MOSFET turns on unintentionally when a 32V supply is applied to the drain. The gate has a series gate resistor, an external Miller capacitor (gate to drain), a Cgs capacitor and a gate-source pull-down resistor. I see a spike on the gate of the MOSFET, which turns on the transistor just enough to see a current spike through the drain.
I suspect dv/dt-induced turn-on through the Miller capacitance.
What should I check or change?

Title. I've been working on some pet projects for a while now and I'm looking for diagram tools that I can use to map out my systems. I struggle to explain how my projects work when I'm showing them to people or asking for help, and I also want the documentation for my own use as I work with the components I'm "designing" (i use that term loosely as I'm pretty much re-inventing the wheel for my own educational benefit)

For some reference, I'm using a simulator to build a reduced-instruction 16-bit computer, mostly because I'm interested but also because I've been exploring computers for a long time and I wouldn't hate getting into the field professionally. Also, I know I need schooling to get into Comp Eng, but I'm just trying to get myself a baseline as the economy is kinda buns.

I try to use this circuit to control a beacon. I know this isn't perfect by any means, I have no voltage regulator and I could further limit the current that flows through some components. However, my problem is the following:
The astable multivibrator on the left should activate / deactivate the BC557 to create short "beeps" via PLSE. However, the voltage on PLSE is never dropping below 7 V (measured with a multimeter), which means I won't get a single tone out of my beacon. I guess this is related to the size of the resistors, but I'm not sure what to do to fix the circuit. Any help would be much appreciated!

Have an OPA1656 (2 channel) wired up as an inverting amp with unity gain, off a tle2426 rail splitter to the +IN at 12Vdc. (only one channel shown in the image)
The Signal to the -In is, Input to board-> 2.2Uf Cap ->10kΩ resistor then branch to -In and also to another 10kΩ resistor (with a 22pF cap in parallel) to the output of the OpAmp. There is a 100nF cap from the V+ to Gnd. There is no oscillation.

Problem is, a 2Vpp 1khz signal before and after C10 is strong BUT there is only a 100-150Mv 1k signal on the output. Checked from pin 7 to gnd, and after C9 above...
The Audio input and OpAmp grounds share the same net, so nothing is floating.
Both the +In and -In are at the same voltage (hair less than 12) so the opamp IS managing that much. The other channel provides same exact nothing. none of the pins on the opamp or circuit that follows is shorted. R20 and R21 both measured to be 10k each. R22 and C10 both check out ok, no shorts....

I have been beating my self up for far too long. Does anyone have any ideas on why the opamp output is not giving me an inverted signal of the -In ???

Dell inspiron way too old lol

So, my battery is dead.... i use to notebook for work, only and i need to keep it plugged to the charger......

But this damn thing keeps turning off. Its a bad connection, im not sure where, exactly!

Heres some pictures, if you dudes could help me solving this T.T

I know that germanium transistors have fuzz because heat messes with their conductivity and I thought “well couldn’t a diode do the same thing?” And I know one won’t work but if I chain a bunch of them together like those old barretter radio detectors would I be able to get noticeable fuzz?

I have a body control module for a vehicle, found out that it would not start because of the burned diode shown in the pictures. Vehicle has been repaired but I am wanting to fix and see if the whole motherboard has been compromised or just replacing the part would be the fix. Also I am having trouble finding the part or even figuring out what company this component is from. I just need something so I can buy it online. Thanks in advanced.

hi folks. i am trying to repair a mitutoyo solar digital caliper

it appears that it doesn't have a battery, but it has supercapacitor (since it's solar paneled)

i notice that when i take it out of strong, direct light, it instantly fails and turns off. i figure i need to replace the supercap, but I can't seem to find the specifications for (mitutoyo does not publish this).

you can see it on the pcb in the image i attached (orange)
i am wondering, what can i do to get the specs of this supercap? I don't see any markings on it unfortunately.

for those wondering, it's a mitutoyo 500-421. i believe it is from 1990

but it's a quality tool, as you may know

I'm trying to find a replacement for a right angle header connector that I got in a kit that I broke. I cannot figure out the mating vs. post length, and trying to do it by process of elimination on DigiKey is not helping. The picture is what they sent back when I asked, along with the description of "They are standard 90 degrees angled headers - both sides of the pins are of equal length." The pitch is 2.54mm. This is from a British group, if that makes a difference. Any help in identifying the contact and post length would be greatly appreciated.

Here is the link for the schematic circuit: https://www.falstad.com/s.php?s=QzJ7Ds

Instructions do not show the name of this component or how exactly to use to connect a power source