VOGONS

How to remove AT power connector?

Topic actions

First post, by peter_shaw

Posted on 
User metadata
Rank Newbie
Rank
Newbie

Hello,
I am new to vintage computing and recently got my hands on an old pentium machine with an AT power supply.
I measured the voltages. Sadly, they were a little bit out of spec:
5 V rail: 6,5 V
15 V rail: 16,5 V

I tried to remove the AT power connector, but it would not budge.
Any pointers? Just blunt force?

I started the PC anyway and it runs fine and stable. Even installed Win 95 on it.
Would you advice to replace the power supply, or is it fine?

My humble vintage PC collection: https://www.peter-shaw.de/2023/10/vintage-pcs/

Reply 1 of 9, by zyga64

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie

Standard AT PSU doesn't have 15V rail. 12V is max. https://en.wikipedia.org/wiki/Power_sup ... g_diagrams
Is this some special/ custom computer ? Or maybe you multimeter has bad battery 😀

Scamp: 286@20 /4M /CL-GD5422 /CMI8330
Aries: 486DX33 /16M /TGUI9440 /GUS+ALS100+MT32PI
Triton: K6-3+@400 /64M /Rage Pro PCI /ES1370+YMF718
Seattle: P!!!750 /256M /MX440 /Vibra16s+SBLive!
Panther Point: 3470s /8G /GTX750Ti /HDA

Reply 2 of 9, by ciornyi

Posted on 
User metadata
Rank Member
Rank
Member

It's very high values and definitely have to be replaced.

DOS: 166mmx/16mb/Y719/S3virge
DOS/95: PII333/128mb/AWE64/TNT2M64
Win98: P3 900/256mb/SB live/3dfx V3
Win Me: Athlon 1333/256mb/Audigy2/Geforce 2 GTS
Win XP: E8600/4096mb/SB X-fi/HD6850

Reply 3 of 9, by peter_shaw

Posted on 
User metadata
Rank Newbie
Rank
Newbie

I measured on an IDE connector. You are right, it should be 12 V, not 15 V. Maybe my multimeter is also bad? The PC runs fine..

My humble vintage PC collection: https://www.peter-shaw.de/2023/10/vintage-pcs/

Reply 5 of 9, by oh2ftu

Posted on 
User metadata
Rank Member
Rank
Member

Did you have any load on it?

Reply 6 of 9, by PC Hoarder Patrol

Posted on 
User metadata
Rank l33t
Rank
l33t
peter_shaw wrote on 2023-08-24, 09:34:

Any hints on how to remove the AT power connector from the socket?

Try gently rocking each connector front to back whilst pulling up on them - they can be quite stiff, especially if they've never been removed since installation (may also be some mild oxidation in play)

The attachment P8 P9 Removal.jpg is no longer available

then just tilt to clear any locking lugs

Any pics you have may make things clearer

Reply 7 of 9, by zyga64

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie
peter_shaw wrote on 2023-08-24, 09:34:

I measured on an IDE connector. You are right, it should be 12 V, not 15 V. Maybe my multimeter is also bad? The PC runs fine..

Measure 12V line in another good known PC PSU. You will know for sure !

Scamp: 286@20 /4M /CL-GD5422 /CMI8330
Aries: 486DX33 /16M /TGUI9440 /GUS+ALS100+MT32PI
Triton: K6-3+@400 /64M /Rage Pro PCI /ES1370+YMF718
Seattle: P!!!750 /256M /MX440 /Vibra16s+SBLive!
Panther Point: 3470s /8G /GTX750Ti /HDA

Reply 8 of 9, by peter_shaw

Posted on 
User metadata
Rank Newbie
Rank
Newbie

any pointers on atx to at adaptors? I just read there might be Problems with some soundcards because they need -5 V, which ATX doesn't provide?

My humble vintage PC collection: https://www.peter-shaw.de/2023/10/vintage-pcs/

Reply 9 of 9, by DerBaum

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie

You can check if your cards need -5v if you look at the card and determinate if B5 of the ISA connector is connected on the card.
https://upload.wikimedia.org/wikipedia/common … SA_Bus_pins.png
Most of them dont use it...

The attachment Screenshot 2023-08-27 233700.png is no longer available

FCKGW-RHQQ2

Go to top of page Go to top of page
Back to General Old Hardware
Close window
Close window