Reddit:Electronics

I know enough about electronics to get myself in trouble but not much more. My wife's Grandpa had this old 8mm projector and looks like a capacitor was added at some point. It hooks up inside to this transformer (I think). The projector surprisingly works great! But the motor starts to slow down after running for 10-15 min and the capacitor gets real hot. I'm assuming it's going out? As soon as the motor started slowing down I turned it off so I wouldn't break anything. Any ideas on what the specs would be for this capacitor? I looked online and couldn't find any info on a "R50T1 Mallory" capacitor. Any guidance would be greatly appreciated?

First Project that has moved from breadboard to something more permanent. None of the potentiometers are square, and some of the solder joints may make you cringe. But that's how we learn. The code runs about 350 lines of circuitpython. What is it? A fencing training assistant.

To commemorate the 38th anniversary of Chernobyl, we're launching OpenRad - an open-source project for building your own radiation dosimeter! Built on ESP32 TTGO T-Display and the SBM-20 Geiger tube, OpenRad allows you to monitor environmental radiation.
Full details & instructions on the Hackaday project page and GitHub repository:
Hackaday project page: https://hackaday.io/project/195778-openrad
Hackster: https://www.hackster.io/omarkhkhorshid/openrad-a-simple-dosimeter-powered-by-esp32-cee321
GitHub repo: https://github.com/omarkhorshid/OpenRad
YouTube video: https://www.youtube.com/watch?v=kaBPnBUhCXA

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This beast is almost impossible to carry by one person. Aside from the normal frequency counter stuff, there is a full CPU inside built on descrete ICs. Extracted boards on the last photo are arithmetic logic unit and RAM.

First project I've done on my own with no tutorial to follow. Using an L293D to drive 4 5v pumps and controlling them with 4 capacitive soil moisture probes. Working pretty good so far!

Mirrored a symbol in the schematic for better readability, got a phonecall, forgot to mirror the signals too when I continued. Did this botch so I can continue writing the firmware whilst waiting for the fixed board to arrive. So, how is your "Revision A" going?

Hey guys, trying to fix my buddy's Rock Band guitar because they go for like 500 on ebay. So there are two AAs in the battery holder, both are tested good at 1.5 volts. With the batteries installed, between the contact circled in red and both pins in the connector circled in blue, I get +1.5v. I would assume I should have +1.5v on one and -1.5v on the other. I also have 0v across the pins circled in yellow, and I would think I should have 3v. Does it sound like there's a short in the battery holder, or am I missing something here?