VOGONS


First post, by the_ultra_code

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Hello VOGONS members!

I have a project that I'm thinking on potentially undertaking. You see, I have an Asus P3B-F motherboard that I used in my first retro build, and now and planing to use in another. Since I took ownership of it, I have built up a list of problems I have experienced with it: iffy Primary IDE port, non-working "Power Fan" header, what I think is a "noisy" AGP slot, and finally, the focus of this thread, a I-guess-you-would-call-it PS/2 "hub" whose PS/2 mouse port is dead.

CFnP8Cql.jpg
g2f8qVvl.jpg

The hub has seen better days, with discoloration/corrosion on the outside of it that I can't remove with 91% isopropyl alcohol, and what seems to be "corrosion" on the "bottom" of the hub, between the hub and the PCB.

This dead mouse port isn't a deal-breaker, since in the past I have found that under MS-DOS mode with the CuteMouse driver that Philscomputerlab includes with his MS-DOS Starter Pack, my PS/2/USB V7 mouse works just fine plugged into the board's USB port (this was the only use case where if the driver wouldn't work with my mouse over USB, it would have been a deal-breaker), but now that I feel like I should start taking more aggressive measures to preserve the retro parts I get (which includes doing some soldering), I think that this would be the perfect and hopefully a relatively "safe" project to complete with my soldering iron and spare time.

Now, the questions. Does anyone know where I could find a replacement hub to swap in? Would I even need to get a replacement; would just heating up the solder points for the hub, or just replacing the solder with new solder do the job? And, finally, for someone with very little soldering experience, is this actually a good idea? 😜

Any help would be appreciated!

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Other:
* USB2 PCI Card in Win98 SE
* Futuremark Result Browsers

Reply 2 of 13, by eisapc

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Problem is to remove the old socket from the board. I´d recommed cutting it off with a Dremel and remove the pins one by one, or use a heatgun to remove it complete. I had good experience with cleaning the empty holes with a solder sucker first and open them up from solder remains with a Dremel afterwards. You could try soldering a socket from a dead board to the contacts first, to make sure its only the socket and not some i/o-logic in the chipset.
eisapc

Reply 3 of 13, by gdjacobs

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dr.sbaitso wrote:

You should be able to find PCB mount 6-pin mini-DIN stacks on ebay. Some electronics suppliers will have these too (https://www.cablesandconnectors.com/26500-26.HTM for example).

Or salvage one. It's by far the most common arrangement for PS/2 ports on ATX boards.

All hail the Great Capacitor Brand Finder

Reply 4 of 13, by the_ultra_code

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dr.sbaitso wrote:

You should be able to find PCB mount 6-pin mini-DIN stacks on ebay. Some electronics suppliers will have these too (https://www.cablesandconnectors.com/26500-26.HTM for example).

Awesome! Thanks for that strangely quaint online store. Found a replacement dual PS/2 port on there, and just bought it. Hopefully it's what I need, and if it is, I'll begin desoldering and cleaning to prepare the board for the replacement. If I can do this properly, and if it all works out, I'll be so excited! 🤣

eisapc wrote:

Problem is to remove the old socket from the board. I´d recommed cutting it off with a Dremel and remove the pins one by one, or use a heatgun to remove it complete. I had good experience with cleaning the empty holes with a solder sucker first and open them up from solder remains with a Dremel afterwards. You could try soldering a socket from a dead board to the contacts first, to make sure its only the socket and not some i/o-logic in the chipset.
eisapc

Um, I'm not sure why you are referring to a "socket". Also feel as though a Dremel would be going too far. However, your suggestion regarding taking a connector from a dead motherboard, just like gdjacobs suggested:

gdjacobs wrote:

Or salvage one. It's by far the most common arrangement for PS/2 ports on ATX boards.

is a good one. Sadly, don't have any completely dead motherboards around to salvage from, sadly, so I had to buy a new connector. 😒

Any who, once I desolder the connector, I might need some help regarding how to solder it back on. Specifically: Any best practices when soldering on a new PS/2 port? Do you start with the little leads, or do you first solder the bigger legs?

Builds

Other:
* USB2 PCI Card in Win98 SE
* Futuremark Result Browsers

Reply 5 of 13, by gdjacobs

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I'd probably do the big lugs first so the signal pins aren't stressed when the solder shrinks. When soldered, the big lugs will hold it rock steady.

All hail the Great Capacitor Brand Finder

Reply 6 of 13, by the_ultra_code

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gdjacobs wrote:

I'd probably do the big lugs first so the signal pins aren't stressed when the solder shrinks. When soldered, the big lugs will hold it rock steady.

Noted.

Okay, so today I received everything I needed to begin to desolder the PS/2 connector. With some help from these two videos (https://youtu.be/HZLQzBOOQbw,https://youtu.be/OtOAMO911Gc), I was able to do a, in my eyes, do a C-/B+ level desoldering job. Wasn't easy, though, since taking what you saw and trying to apply what you saw is hard, at least in this case, with me. Took a lot of solder, time, and effort to get the connector off, but I was finally able to.

Here's both sides of the PCB after the desoldering job and after thoroughly cleaning each side with isopropyl alcohol:
i4RjRWbh.jpg OiBbURRh.jpg

The top of the PCB looks pretty dirty/corroded, as far as I am concerned.

Here's a side-to-side of the old connector with the new one I bought:
WHWidcJh.jpg

I will say, I learned at least two things during this desoldering session: one, getting the right amount of solder on the tip of the iron to use in desoldering, the angle at which you place the iron with the solder on the joint, and the placement of the Soldapullt when you go to suck up the molten solder are all crucial in doing a clean desoldering of a joint; two, I should have gotten some RA liquid flux, because trying to use wick without it I'm sure is not as effective as it is if I had it. Going to get some to d a final cleaning of the PCB before I go ahead and do the soldering.

What do you guys think of my desoldering work? Good? Bad? Love the feedback. 😀

Builds

Other:
* USB2 PCI Card in Win98 SE
* Futuremark Result Browsers

Reply 7 of 13, by Thermalwrong

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It looks good, those ground areas do a lot of heatsinking so getting them clean with a solder sucker is quite difficult - mine rarely look so tidy 😀

I definitely agree on the technique part, one thing I've learned so far is that using a high temperature and putting in some low-temp solder helps most, I haven't seen any vias/holes damaged that way yet.

Reply 8 of 13, by Mister Xiado

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Spiffy. As far as de-soldering goes, I lay the wick across the flux, then touch the iron to it so it melts and is wicked into the uh... wick. Then apply it to the solder that is to be removed. Seems to be effective, but nothing tops a Hakko, not that I'll ever have one.

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Reply 9 of 13, by .legaCy

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Thermalwrong wrote:

It looks good, those ground areas do a lot of heatsinking so getting them clean with a solder sucker is quite difficult - mine rarely look so tidy 😀

I definitely agree on the technique part, one thing I've learned so far is that using a high temperature and putting in some low-temp solder helps most, I haven't seen any vias/holes damaged that way yet.

On big parts that heatsinks the heat from my dessoldering station, usually i go to the overkill route and use my hot air station blowing the area, and also a little help with my soldering iron.

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Reply 10 of 13, by gdjacobs

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On parts that I don't really care about, I'm even more medieval and de-solder with a heat gun.

All hail the Great Capacitor Brand Finder

Reply 12 of 13, by the_ultra_code

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photomaster wrote:

@the_ultra_code

Have you managed those ports to work?

Sure as hell been a long time, huh? 🤣

Well, I soldered on the new PS/2 port. Nothin'. A few months later recapped 90% of all capacitors on the motherboard in the long-shot hope it would help. While it did allow me to POST with a 1.1GHz 100MHz-FSB S370 PIII in a slocket, it only helped... eh, 5% with the PS/2 port? I believe it now reaches the BIOS more gracefully before making the board crap itself. I have long-since given up on the port. Either there is trace damage, a surface-mount device is missing somewhere, or a combination of both that's causing this issue, but whatever it is, I don't have the expertise nor the required documentation to determine if any of those guesses are true.

But, it's okay. The board is now enjoying retirement in an anti-static bag in a nice drawer on a storage rack. I have an Asus P3V4X that'll handle any Slot 1 CPU testing that I might conduct, from P2s up to 1GHz P3s.

Sorry for leaving it on a cliff-hanger.

Builds

Other:
* USB2 PCI Card in Win98 SE
* Futuremark Result Browsers

Reply 13 of 13, by Doornkaat

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I think the_ultra_code has permanently retired his board but to anyone else reading this topic in hopes of repairing their own board:
A non-functional PS/2 port in my experience is more often than not the result of a defective fuse.
PS/2 is not designed for hot plugging so there are fuses to prevent overcurrent from damaging the controller. On newer boards (like this one) those are mostly large green rectangular parts (in this case the ones with P and 110 on them, labelled FUSE1 + FUSE2 on the pcb), on older AT boards they are mostly large green resistor like looking through hole parts near the connector.
Many of those fuses are supposed to be self resetting but that feature doesn't always work right. Especially with a sporadically working port it's a good bet to simply bridge the fuse with a small wire and see if the problem is solved. If it helped remove the wire and replace the fuse to complete the repair.
Good luck! 😀