Malalkin

So it seems pretty random, but last week my computer crashed out of the blue with just a checkerboard pattern of static on the screen (everything frozen). When I tried to reboot, it wouldn't POST. I played around with some wires, moved the memory to the second memory channel, checked that the CPU cooler was mounted correctly and nothing changed, but then I removed the DVD drive and it started working again for a while. I was able to run it for 3 days straight without rebooting and there were no issues. I thought "maybe the DVD drive is dead?". To save wear&tear when I'm just number-crunching, I unplug the 2 SATA hard drives and just boot off a USB drive. When I unplugged the SATA disks from power and SATA, it wouldn't POST again. Cleared CMOS: no change. I managed to get a POST by unplugging the VGA cable from the back. It kind-of booted, but couldn't find an operating system (which usually happens because I have to change BIOS options). I ctrl+alt+deleted and dropped into the BIOS menu where things got kind of strange: it worked for about 5 seconds and then locked up with another checkerboard static pattern on the screen, this time the system speaker emitting a constant 'beeeeeep' (no beep code, just a solid beep). I hit the reset button again and no POST. Feeling defeated, I reconnect all the SATA drives and power it on 'just to see' and it works just fine. I'm thinking maybe PSU, but if that were the case how could it stay stable for 3 days straight? This system has worked without issues since 2010 and nothing has changed on it recently to cause this. Any suggestions? EDIT: system specs: AMD Phenom II X3 M4A785 motherboard (onboard graphics) 4GB DDR2 at 800mhz 2x SATA hard drives + 1x IDE EVGA 500W bronze PSU

Just a phone. Like my old Nokia phone from the 2000s, no special features, nothing fancy; just something I can toss in the glovebox and use if I get stranded. There's a charging port in the glovebox, so no need to worry about the battery dying. Apparently the 3G towers in my area are shutting down next year, so I'll need something that can meet the current standards. Where can I get a very basic, cheap, fundamentals-only emergency phone? Everywhere I look, I can't find something basic. All I've turned up so far is some cheap 'Alkatel Go Flip' which looks like it wouldn't be reliable in an emergency.

Didn't know about most of those things. Although the second image is a ferrite core (it's just wrapped in plastic). Thanks for the link. To be clear, I am trying to build something of a boost converter, just one that doesn't destroy itself. My previous project was a 555 timer creating a square wave which went into a small 300:1 transformer and then a voltage multiplier network to yield about 200 volts. It was ridiculously large and inefficient.

Now the ratio is 4:9 on a torroid, but the output is still 1:1. Although there's very little copper in play.

Here's basically the schematic from wikipedia: The windings on the transformer are the same resistance so it's probably 1:1, but anything I found online didn't seem to specify anything about winding ratios for joule thief devices. Do I need a different transformer/coil then?

I mostly wanted to just build a joule thief to prove a point, but I was thinking in the future I could play around with it and try boosting the output enough to charge a 200V capacitor using a dead battery

I'm using only electronics I pulled from an old TV. I followed the schematic from wikipedia as well as I could, and I'm about 90% sure the coil is going in the correct direction. But for some reason if I feed it 1.4V, I get 1.4V out (before the diode, so my capacitor only charges to 1.1V after the diode). Transistor: C945P (tried swapping the transistor to no avail); looking on the flat side, the pinout is emitter-collector-base. Resistor: 810 ohm Inductor: I don't know what the inductance is, but there's a '12' written on the side and the top has the numbers 47E00-0110 Red magnet wire (+), brown magnet wire (-) Any idea what I've done wrong here?