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AT Power supply for 386.

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First post, by Baoran

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I have been planning to build a 386 PC for some time. I have a motherboard and the CPU and possibly a hard drive that might work with it.
What kind of AT power supply I should go for? Is there a brand that made good power supplies back then or are those new ebay power supplies like Athena and Sparkle better?
There is someone selling 230W DTK PTP-2008 cheap near where I live. Is that any good?

Reply 1 of 24, by MERCURY127

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Baoran wrote:

There is someone selling 230W DTK PTP-2008 cheap near where I live. Is that any good?

yes, if his interior is clean and capacitors remains in good condition... I have some old AT PSU 25 years old, and use it episodically. He work good!

Reply 3 of 24, by Baoran

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The person selling it sent me a low quality picture of it.

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Reply 6 of 24, by brostenen

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Yup... That is an AT psu.

A couple of hints:
You can allways mount an ATX psu inside an AT case, it just need to be mounted on it's head. (upside-down).
If the ATX psu is in good shape and has -5volt (white wire), you can buy a cheap ATX-AT converter on eBay.
If the ATX PSU do not have -5volt, then you can buy a converter that are not too expensive though not cheap.
This, more expensive one, has a converter on it that gives you -5volt output.

The power button on any AT case, are designed for 110/220 volt, though they can handle low volt as well.

EDIT:
The best you can do, if you are 110 percent paranoid about PSU's blowing up, is to purchase a decent good
quality ATX psu wich are brand new, and buy that converter with -5volt generator on it.

Don't eat stuff off a 15 year old never cleaned cpu cooler.
Those cakes make you sick....

My blog: http://to9xct.blogspot.dk
My YouTube: https://www.youtube.com/user/brostenen

001100 010010 011110 100001 101101 110011

Reply 7 of 24, by MERCURY127

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i know nothing about quality of this thing... if u have multimeter, u can check output voltage on molex connectors befor buying:
red - black must be 5 V
yellow - black must be 12 V
allowed divergence is 5% from nominal. but remember, that under load this divergences can grow...

Reply 8 of 24, by deleted_Rc

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whenever you recieve or buy it, first thing you do is check with the multimeter for the right voltages, following check/replace the fan and check the caps. overheating PSU can blow your entire right.

MERCURY127 wrote:
i know nothing about quality of this thing... if u have multimeter, u can check output voltage on molex connectors befor buying: […]
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i know nothing about quality of this thing... if u have multimeter, u can check output voltage on molex connectors befor buying:
red - black must be 5 V
yellow - black must be 12 V
allowed divergence is 5% from nominal. but remember, that under load this divergences can grow...

thats for the 5V rail and pretty much the same for 3.3V however the 12V rail has a wider allowed divergence usually around 10-12%

Reply 9 of 24, by Baoran

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I am kind of new with this building old computers. I just have lots of old parts saved from my old computers. Is there a guide how to do all that without electrocuting yourself?

Richo wrote:

whenever you recieve or buy it, first thing you do is check with the multimeter for the right voltages, following check/replace the fan and check the caps. overheating PSU can blow your entire right.

Reply 11 of 24, by brostenen

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Baoran wrote:

I am kind of new with this building old computers. I just have lots of old parts saved from my old computers. Is there a guide how to do all that without electrocuting yourself?

Richo wrote:

whenever you recieve or buy it, first thing you do is check with the multimeter for the right voltages, following check/replace the fan and check the caps. overheating PSU can blow your entire right.

Dont worry.... It is only the power switch on an AT supply, that have 110/220 volt. Everything else are 3 to 12 volts.

Don't eat stuff off a 15 year old never cleaned cpu cooler.
Those cakes make you sick....

My blog: http://to9xct.blogspot.dk
My YouTube: https://www.youtube.com/user/brostenen

001100 010010 011110 100001 101101 110011

Reply 12 of 24, by deleted_Rc

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Baoran wrote:

I am kind of new with this building old computers. I just have lots of old parts saved from my old computers. Is there a guide how to do all that without electrocuting yourself?

Richo wrote:

whenever you recieve or buy it, first thing you do is check with the multimeter for the right voltages, following check/replace the fan and check the caps. overheating PSU can blow your entire right.

Safest way to do so is letting it deliver and not test it, just screw it open and look for leaking/bulging caps (this means they are broken, ones that look fine do not garantee they are working), if 1 more are broken a recap might be advised (some would say this is not necessary and would just replace the broken ones, its cheaper and less work but in the long run). usually it takes just a few hours for a PSU to fully discharge itself but since its been mailed to you without any power on it for a few days atleast you are in the clear (just dont sit in a bucked full of water just incase 🤣 ). The fan you could test and leave the old one in but replacing it costs at most €10,- with a brand new higher CFM and low noise one(do remember to watch the wires as they might reverse the wires to prevent replacing them(, but those old PSU fans could not be working and overheat it resulting in a message to the local indians 😵

Reply 13 of 24, by Baoran

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I have a basic one without auto range and all that.

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I have another AT PSU in the pentium 100Mhz that I built earlier that I could practice with. It has alot of dust inside so it needs some cleaning anyway.

Reply 14 of 24, by MERCURY127

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Good. Set voltage limit to 20 v and measure molex, as i say. Also check fan when psu plugged in wall. U must sense air flow, and it should not smell!
If all look good, open psu and clean all with brush.

Reply 16 of 24, by deleted_Rc

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MERCURY127 wrote:

Good. Set voltage limit to 20 v and measure molex, as i say. Also check fan when psu plugged in wall. U must sense air flow, and it should not smell!
If all look good, open psu and clean all with brush.

compressed air and isopropanol tends to work better, I use a distilled water spray bottle to clean with isopropanol and then blow the residue off with compressed air. try sticking a toothbrush in a PSU 😒

Reply 17 of 24, by Ampera

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Newegg still sells AT PSUs.

https://www.newegg.com/Product/ProductList.as … 657%20600014008

Im not sure about the others, but the Athena PSU is what I use and it runs fine, however I paid a lot less for it when I got it, so you may want to try the star tech one.

Reply 18 of 24, by deleted_Rc

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Ampera wrote:

Newegg still sells AT PSUs.

https://www.newegg.com/Product/ProductList.as … 657%20600014008

Im not sure about the others, but the Athena PSU is what I use and it runs fine, however I paid a lot less for it when I got it, so you may want to try the star tech one.

FSP still sells new AT PSU aswell, thats in europe though:

FSP Fortron SPI-250G

Reply 19 of 24, by Baoran

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You are talking about the sparkle, right?
Is that a good brand?

Richo wrote:
Ampera wrote:

Newegg still sells AT PSUs.

https://www.newegg.com/Product/ProductList.as … 657%20600014008

Im not sure about the others, but the Athena PSU is what I use and it runs fine, however I paid a lot less for it when I got it, so you may want to try the star tech one.

FSP still sells new AT PSU aswell, thats in europe though:

FSP Fortron SPI-250G

Last edited by Baoran on 2017-04-03, 15:07. Edited 1 time in total.