VOGONS


First post, by NightShadowPT

User metadata
Rank Newbie
Rank
Newbie

Hi,

As stated on another topic, I have recently acquired a Compaq Deskpro 486/33.

That PC came upgraded with a Cyrix cx486 DX-2 @66Mhz, but there is no fan installed on top of the CPU cooler.

To compensate for it, I was thinking about getting an 80mm fan in the case blowing past the CPU, but I have hit a "slight" snag... I cannot seem to find any place where I can connect the fans at all - there are no 5v pins on the board and all my fans are 5V 80mm Noctua fans - so I cannot just use a Molex to fan adapter.

While thinking about options I noticed that my AWE seems to have an awful amount of pins going out of it... and I had a crazy idea that maybe one of them could be a 5V one I can use.

I guess my questions here are:
1 - Is there a 5v output from the AWE32 that I can use?
2 - If there is, should I use it for this purpose or is it not advisable
3 - Any other suggestions short of buying a 12v fan?

Thanks!

Reply 1 of 11, by RandomStranger

User metadata
Rank Oldbie
Rank
Oldbie
NightShadowPT wrote on 2022-10-09, 18:21:

there are no 5v pins on the board and all my fans are 5V 80mm Noctua fans - so I cannot just use a Molex to fan adapter.

Why not? The red wire is 5V and there are adapters that use that instead of the 12V or have both.

sreq.png retrogamer-s.png

Reply 2 of 11, by darry

User metadata
Rank l33t++
Rank
l33t++

You can use a Molex to fan adapter, you just need switch the wire from the 12V to the 5V pin on the adapter. The Molex connector carries both 12V and 5V.

I would be surprised if pre-wired adapters of that kind did not already exist.

EDIT: @RandomStranger, you beat me to it.

Reply 3 of 11, by weedeewee

User metadata
Rank Oldbie
Rank
Oldbie

something like this could do.

https://www.amazon.co.uk/15cm-Akasa-Fan-Cable … s/dp/B001J2YRU2

716nZM2VDaL.__AC_SX300_SY300_QL70_ML2_.jpg

Right to repair is fundamental. You own it, you're allowed to fix it.
How To Ask Questions The Smart Way
Do not ask Why !

Reply 5 of 11, by NightShadowPT

User metadata
Rank Newbie
Rank
Newbie

Clearly my bad...

When I searched for Molex to fan adapter I could only find 12v versions, so I just assumed it only had 12v.

Thanks for clarifying that it also carries 5v, it is without any doubt the cleanest solution I can get.

Cheers,

Reply 6 of 11, by weedeewee

User metadata
Rank Oldbie
Rank
Oldbie

FYI, in the photo I posted, two of the connectors are wired for 12v, the other 2 are wired for 5v.

Right to repair is fundamental. You own it, you're allowed to fix it.
How To Ask Questions The Smart Way
Do not ask Why !

Reply 7 of 11, by darry

User metadata
Rank l33t++
Rank
l33t++
weedeewee wrote on 2022-10-10, 15:11:

FYI, in the photo I posted, two of the connectors are wired for 12v, the other 2 are wired for 5v.

@OP Do not mix them up and preferably test before use that they are wired correctly .

Reply 8 of 11, by kdr

User metadata
Rank Member
Rank
Member

I often re-wire the Molex connectors of 12V fans to run them off the 5V rail instead, this makes them run fairly slow and very quiet. If you have a tiny screwdriver and some patience it's possible to slide the pins out of the plastic housing, so you don't even need to crimp or solder anything!

(Edit: of course the opposite doesn't apply, you can't take a 5V fan and decide to run it on 12V.... unless you want magic smoke!)

Reply 9 of 11, by psychofox

User metadata
Rank Newbie
Rank
Newbie
kdr wrote on 2022-10-10, 21:13:

I often re-wire the Molex connectors of 12V fans to run them off the 5V rail instead, this makes them run fairly slow and very quiet. If you have a tiny screwdriver and some patience it's possible to slide the pins out of the plastic housing, so you don't even need to crimp or solder anything!

(Edit: of course the opposite doesn't apply, you can't take a 5V fan and decide to run it on 12V.... unless you want magic smoke!)

Lots of 12v fans wont run on 5V voltage (they run but need extra push at start). So i have wired my fans between 12V and 5V wires (12v line to fan + wire and 5V to - ) the voltage between them is about 7 V, this way fan is silent and still has enough cooling power on most cases.

Reply 10 of 11, by RandomStranger

User metadata
Rank Oldbie
Rank
Oldbie

Noctua used to include resistor modded wires for their fans. They call it low noise adapter and ultra low noise adapter. I don't know if they still do. 7V molex-to-fan adapters also exist.

PC-Fan-Cable-Distributor-4-Way-Molex-to-4x-3-Pin-Fan-Adapter-5V-7V-2x.jpg

sreq.png retrogamer-s.png

Reply 11 of 11, by kdr

User metadata
Rank Member
Rank
Member
psychofox wrote on 2022-10-11, 13:41:

Lots of 12v fans wont run on 5V voltage (they run but need extra push at start). So i have wired my fans between 12V and 5V wires (12v line to fan + wire and 5V to - ) the voltage between them is about 7 V, this way fan is silent and still has enough cooling power on most cases.

Oh that's a clever trick!