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View Full Version : IBM 5150: Trying to identify manufacturer of P8/P9 connector



inaxeon
February 27th, 2017, 05:54 AM
Heya

I've been plagued by connection problems on my PC (Model A) between the power supply and mainboard. From looking at the contacts, they are quite badly corroded. I'd like to replace them, but stuffed if I can figure out what they are!

It is well known that Molex made connectors like this (90331, I own quite a few and with contacts) but this is not what IBM used in the PC (Certainly not mine anyway). The PC's are a couple of millimeters longer, and 90331 pins don't quite fit in.

I have been googling for hours, cannot find any other manufacturer of this type of connector. The PC's even have part numbers on them, but which turn up bupkis in search results.

Is anyone away of any other part numbers for these connectors?

Cheers

Stone
February 27th, 2017, 07:01 AM
I might have a dead PSU I can cut them off of. Then you can just splice the wires together.

paul
February 27th, 2017, 11:52 AM
No doubt you've come across this page then? Perhaps they'll send a sample...

https://www.alibaba.com/product-detail/3-96mm-pitch-bar-connector-P8_1867002559.html

Agent Orange
February 27th, 2017, 12:07 PM
No doubt you've come across this page then? Perhaps they'll send a sample...

https://www.alibaba.com/product-detail/3-96mm-pitch-bar-connector-P8_1867002559.html

You need to be careful when dealing with Alibaba, as many of their suppliers require you to order a 'boat load' of any particular item.

Chuck(G)
February 27th, 2017, 03:27 PM
Maplin simply calls them "AT Motherboard power connectors":

http://images.maplinmedia.co.uk/at-motherboard-power-connector.jpg?w=283&h=283&r=4&o=M0KjZMiXbt5aKl9TSHXPv0QkSfUj&V=ORaH

Perhaps they can be persuaded to give up their source.

One thing that's played hob with old connectors is RoHS. Many manufacturers simply discontinued production rather than re-engineer their old products.

inaxeon
February 28th, 2017, 01:15 AM
Maplin simply calls them "AT Motherboard power connectors":

http://images.maplinmedia.co.uk/at-motherboard-power-connector.jpg?w=283&h=283&r=4&o=M0KjZMiXbt5aKl9TSHXPv0QkSfUj&V=ORaH

Perhaps they can be persuaded to give up their source.

One thing that's played hob with old connectors is RoHS. Many manufacturers simply discontinued production rather than re-engineer their old products.

Interesting find on Maplin, I will go down and clean them out of those this lunch time (for a different project!)

The issue with the above mentioned is that they are all exact 90331 clones, which aren't contact interchangeable with the IBM's. My suspicion is IBM used an AMP connector. I have found some mentions of them, but stuffed if I can find a full part number.

Another problem is that being a Model A it has a very early power supply, which also has connectors inside the supply that have failed on me, whereas in later models the wires are soldered directly to the PCB (more reliable!) - so I've got quite a lot of contacts to replace.

I just don't want to go chucking away any more of the original hardware than I have to!

Chuck(G)
February 28th, 2017, 06:25 AM
They could well be Amp, but if so, that connector's vanished from their product line. It does seem reasonable that IBM would go with a major brand (Amp, Amphenol, ITT Cannon, etc.) at the time and there weren't too many of them. I'll have to grab a 5150 motherboard and see if I see any identification that might tip us off. Also time to check an old catalog or two.

Stone
February 28th, 2017, 07:26 AM
Maplin simply calls them "AT Motherboard power connectors":

http://images.maplinmedia.co.uk/at-motherboard-power-connector.jpg?w=283&h=283&r=4&o=M0KjZMiXbt5aKl9TSHXPv0QkSfUj&V=ORaH

Perhaps they can be persuaded to give up their source.

One thing that's played hob with old connectors is RoHS. Many manufacturers simply discontinued production rather than re-engineer their old products.


They could well be Amp, but if so, that connector's vanished from their product line. It does seem reasonable that IBM would go with a major brand (Amp, Amphenol, ITT Cannon, etc.) at the time and there weren't too many of them. I'll have to grab a 5150 motherboard and see if I see any identification that might tip us off. Also time to check an old catalog or two.He's looking for P8 & P9 connectors, not the motherboard's header. :-)

inaxeon
February 28th, 2017, 08:11 AM
One interesting thing I have noticed about these, is "P4": the connector the AC fan uses. It is exactly the same series, but has 4 positions?.

(Shot of it here)
http://techmattmillman.s3.amazonaws.com/wp-content/uploads/2017/01/extracting.jpg

Molex 90331 was only produced 2 and 6 positions, so there was clearly another player on the scene in the early 80's ;-)

WALDOM Connector is a name I have seen come up a few times in relation to this part but, it appears to have been acquired by molex a long time ago.

Eh. I think I'm wasting my time here. Might just have to rebuild the whole lot with modern parts.

zhouy
March 7th, 2017, 09:49 PM
Buy this cable:
https://item.taobao.com/item.htm?spm=a230r.1.14.22.20HssV&id=530763698219&ns=1&abbucket=6#detail
And remove P8 P9 connectors from the cable with a pin, then replace your bad connectors.