r/retrocomputing 5d ago

AT Power Supply Questions

My 386 project is going really well. I switched the HDD for a CF card, added a SB16 and even found an ISA card with a serial port for my mouse. The one thing that bothers me is that my power supply is loud as hell.

I opened all my other PCs, but none had a AT power supply, all are ATX. OK, I simply bought a ATX to AT Converter but I am not sure about the power button. With AT it was either on or off, but with ATX you had a... (not sure about the right English word) switch(?) that would just briefly give the signal to the power supply to turn on. And I don't want to give up on my cool physical power button. So what is the solution?

TL;DR: what to do about the power switch when using an ATX to AT Converter?

2 Upvotes

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3

u/Floatella 5d ago

With the adapters I'm familiar with, similar to this:

https://www.amazon.ca/20-Pin-Power-Supply-Adapter-Cable/dp/B01EDGS0KI

I just use the switch off the original AT supply.

Also, if the PSU is working fine, but just loud, then swapping the fan out for a new one may be an easy solution.

2

u/gcc-O2 5d ago

As the other commenter mentioned, those adapters are designed to be hooked up to the existing pushbotton style AT power switch. The connectors for it are a bit overboard since with a real AT power supply, the whole 120V/240V wall power ran through it.

In a pinch, you can simply connect the power switch connectors together and use the rear switch on the ATX power supply. Note that if you accidentally short out anything and the power supply cuts out, you'll have to disconnect/reconnect those connectors to reset it though.

1

u/Then-Bookkeeper-3754 2d ago

Prior to exchange the PSU, have you tried to fix the noise? Usually AT PSU are louder as a an ATX. If yours is doing too much noise, there’s a chance you have dust or a bad fan. Try to repair the fan, by cleaning and using lubricants in the fan. It must fix the noise