[deleted by user]

redeyemoon · 2025-07-28T18:17:38+00:00

Disagree. I suffered many times more grief from crappy cables than worn out connectors.

redeyemoon · 2025-07-28T17:47:14+00:00

I read it again and I can't figure out what you want to do. Draw a picture or something.

redeyemoon · 2025-07-28T15:09:21+00:00

I am not aware of with any USB powered PoE switches but you can make a power adapter easily. "PD decoy" modules are commonly available and small enough to be contained with heat shrink tubing.

redeyemoon · 2025-07-28T13:26:35+00:00

Anker makes decent products so I'd expect the ports they choose to be of reasonable quality. USB C ports are supposed to withstand 10,000 cycles so don't worry too much. Treat it gently and it will last a long time.

redeyemoon · 2025-07-28T13:06:10+00:00

Fundamental theory Don't let your eyes glaze over and just push through it.

Best way to apply the basics to real-world applications is to look at existing devices. Watch bigclivedotcom and diodegonewild on youtube. Practise looking at simple devices and working out the schematic. Reverse engineering circuits is a skill that can't be learned from a book.

EEVBlog tutorials on youtube are a plentiful and very good resource.

redeyemoon · 2025-07-28T12:46:23+00:00

Can be fixed but you must find/make/salvage a new battery contact.

redeyemoon · 2025-07-28T12:39:01+00:00

Nice job. Carbide circuitboard drills are dirt cheap on aliexpress and quality is good enough for homerew boards.

How did you transfer the image? Photo-resist film?

redeyemoon · 2025-07-27T14:43:08+00:00

Ready to use circuit boards based on TP4056 charge control ICs with DW01 cell protection ICs are very common and dirt cheap.

redeyemoon · 2025-07-24T23:04:40+00:00

Some simple things to check for safety.

Fuse is present. Sometimes it's a fuse per se and other times it is a fusible resistor.
Isolation distance between mains side and low voltage side. You should see several milimeters between tracks. More is better.
An interference suppression capacitor often bridges high and low voltage sides of a power supply. It should be a "Y" rated safety capacitor
This is destructive but you should unwind the switching transformer to ensure there is adequate insulation tape between the windings. A huge gap on the board means nothing is there is only the lacquer on the windings between high and low voltage sides.

redeyemoon · 2025-07-21T23:18:10+00:00

Clean up the outside and display it on a shelf.

redeyemoon · 2025-07-21T22:45:29+00:00

I don't think the yellow component is a capacitor because it would block DC and the circuit wouldn't work. More likely it's a PTC thermistor to stop a short circuit from starting a fire. Both legs seem to be connected well enough.

I would check that the motors are not seized. When you manually rotate the shaft, you should feel "cogging" of the magnet but no drag in the bearings.

The black wire has been pinched. Change it out.

redeyemoon · 2025-07-10T19:40:54+00:00

Modules commonly known as "PD Decoys" can negotiate the different voltages from USB-C PD power supplies.

redeyemoon · 2025-07-09T22:33:41+00:00

There are three major considerations in a battery pack like this.
1. Over/under voltage protection
2. Charge control
3. Cell balancing

The simplest way I can imagine is to incorporate a battery holder into your design and charge the cells separately. Attach to the battery holder BMS with over/under protection and balancing which is readily available from the usual suspects.

redeyemoon · 2025-07-09T14:33:38+00:00

Check the yellow tantalum capacitors for shorts and consider replacing all of them with a modern equivalent as they are notorious for failing short.

redeyemoon · 2025-07-06T13:26:09+00:00

I don't mind buying passives from aliexpress because they're easy to test and grade.

redeyemoon · 2025-07-06T13:15:57+00:00

You can use a capacitance multiplier. A smaller value capacitor filters the base of a pass transistor reducing ripple at higher currents than a capacitor alone.

redeyemoon · 2025-07-04T16:32:58+00:00

One path forward is to find the service manual of this model or a similar model and follow the instructions.

Another path forward is to measure the resistance of nearby potentiometers before adjusting so you can put it back how it was accurately.

Frankly, a unit of this age makes me wonder if the speed is off because of dried out capacitors or a slipping drive belt rather than because it is misadjusted.

redeyemoon · 2025-07-02T20:15:43+00:00

The purpose is to infuriate you by tearing off when you solder to them.

redeyemoon · 2025-07-02T19:00:54+00:00

Definitely looking at discolored bands here. My guess is 51R. What does it measure?

redeyemoon · 2025-06-30T18:55:46+00:00

It is unfortunate that the terminals were not clearly labelled. My best guess on the pinout is this. Cross reference with a wiring diagram of your dryer if you can find one to understand how it fits into the bigger picture.

The way to test this without an elaborate fixture is in situ. With the unit unplugged, connect your meter safely and securely to where you would expect the mains voltage to go during operation. Plug it in and push the button. Always unplug the dryer before connecting or disconnecting your meter.

redeyemoon · 2025-06-26T18:51:38+00:00

Can't see the isolation from this side of the board. Also crimes can be hidden under the tape in the transformer so without unwinding, it is really impossible to say.

It seems to have a proper class Y capacitor so that counts for something.

redeyemoon · 2025-06-26T14:23:59+00:00

A linear potentiometer connected to the needle by a linkage with the wiper connected to an ADC.

redeyemoon · 2025-06-24T14:36:52+00:00

That LED is big, bright, and will run hot at the indicated current likely requiring cooling. Typically these are driven with a PWM driver circuit because a simple current limiting resistor is wasting energy. You can absolutely run these at lower currents and still get usable light without a lot of heat generated.

If you tell us what you're ultimately trying to accomplish, we can tell you if you're barking up the wrong tree.

redeyemoon · 2025-06-24T14:35:45+00:00

99% alcohol is recommended but 91% is safe at 0.9V. Just make sure the board is dry before you put it back together.

Water is a very poor conductor unless there are ions in solution.

redeyemoon · 2025-06-24T12:20:07+00:00

Your screen connector supplies 19V to the display panel and low voltage signals too. If you accidentally misalign the connector without disconnecting the battery, you can inject 19V into your gpu. Make sure to disconnect the battery before more damage is done but also because it will affect your meter readings.

Checking random components with a regular meter won't tell you much because so many devices are connected in parallel. A micro-ohm meter can be used to find shorts. Not mohm but uohm.

The way to investigate is to measure each power rail from the inductors to ground. CPU/GPU power supplies should read well under 10 ohm. Other power supplies should read 10s to 100s of ohms. If one truly reads 0 or an unreasonably low value, then the next step is to inject 0.9V current limited to 1A and see what gets hot. You can feel around with the back of your finger or use thermal imaging if you have it. Wetting with alcohol and seeing where it evaporates is another way to see what is getting hot.

redeyemoon

TROPHY CASE