Jump to content
wierd_w

Scored a damaged socket 7 on ebay

Recommended Posts

Posted (edited)

So, there was a gigabyte VX chipset socket 7 on Ebay that has a blown resistor.  It has through-hole soldering, so should be an easy fix.

 

It was only 40$, including shipping.

https://www.ebay.com/itm/Socket-7-motherboard-Gigabyte-GA-586ATV-Intel-430VX-Read-description/254580147187?hash=item3b4628c3f3:g:eecAAOSwy11epUp6

 

Does anyone know what value resistor to put in there?

 

Looking at other photos of intact motherboards, it actually appears to be a little Surface Mount ceramic job.  Not sure if capacitor or resistor though.  In either case, there apears to either be "very nice contacts" on either side of the trace, or through-holes on either side of the trace.

 

This is the intact motherboard picture I am looking at..

gigabyte_ga-586atv_rev_4b_socket_7_mothe

 

and this is the damaged one I ordered.

s-l1600.jpg

 

 

I am thinking I can put either a suitable long-legged ceramic cap / resistor on those testpads/thru holes, and it should be right as rain.  I just want some better eyes trying to figure out the damaged bit there.

 

Edit again--

 

Found pics of the back of the board-- Deffo through-holes.  I should be able to replace with a suitable discrete component without much issue.

Edited by wierd_w

Share this post


Link to post
Share on other sites

Found a suitably high quality image of the impacted area, TOTALLY a capacitor.

 

image.thumb.png.c093cec4d31d7c73d62f684b25bb322a.png

 

 

Any suggestions what kind to put there to replace it?

Share this post


Link to post
Share on other sites
Posted (edited)

Wait, the silkscreen labels it with an L number, not a C number (or an R number).  This might be an inductor instead?

 

Yeah, I think it's an inductor. Symbol matches for inductor.  Looks like I will need and LCR meter, and a 1k resistor.  (then look for an identical inductor on the board, and test it)

 

Then I will know what to put there.

Edited by wierd_w

Share this post


Link to post
Share on other sites

Good luck. I'm mostly amazed that a broken and untested Pentium class motherboard is worth $40 and upwards.

  • Like 3

Share this post


Link to post
Share on other sites

Seller claims it still works. (and 40$ is not too much to spend on potential treasure)

 

Working pentium class boards can go for over 200 these days. Too rich for me.  That thing seems tied to ISA slot, and I dont really need ISA card capabilities. If the PCI slots work, I can still use it. (assuming the seller is not a big fat liar, but if he is, oh well.)

Share this post


Link to post
Share on other sites
Posted (edited)

WTF?! So you're saying I have well over $200 stuffed away in the basement? I suppose it only applies to first generation Pentium boards, not the later ATX models. Otherwise I have a small gold mine in the basement, which I definitely should look into converting to money which also gives me more free space.

 

Hm... sell off a handful old PCs that I have no nostalgic feelings attached to, and cover a whole month worth of bills.

Edited by carlsson
  • Like 1

Share this post


Link to post
Share on other sites

Socket 7 boards are still inexpensive. I'm selling some NOS 430TX boards now for $60, and that's a little high. Super Socket 7 (with AGP) are more expensive, as are Socket 4 and Socket 5. Even then, $200 seems a little high, especially for SS7.

  • Like 1

Share this post


Link to post
Share on other sites

Ok, so I can't quit working and live on selling antiques just yet. I figure that SuperSocket 7 boards would be more desirable as those were not common to begin with. Unfortunately I don't have that.

Share this post


Link to post
Share on other sites

the 200$+ ones seem to be industrial boards, and other specialties, like hardware SMP capables.

 

Even still, 40$ is 30% off from 60$.  (especially since it just needs a tiny inductor put in some thru holes.)

Share this post


Link to post
Share on other sites
On 7/2/2020 at 9:44 AM, carlsson said:

Good luck. I'm mostly amazed that a broken and untested Pentium class motherboard is worth $40 and upwards.

oh hellya they are. The 486 is getting pushed out in favor of what comes next, Pentium. Then Pentium II and III next. 5 years out maybe?

 

Nostalgia is a rolling window.

 

 

Share this post


Link to post
Share on other sites

I have a dual-CPU board with ISA slots, SCSI, two 233MMX, and 32MB RAM.  Wonder what that could get these days.

Share this post


Link to post
Share on other sites
On 7/2/2020 at 6:54 AM, wierd_w said:

Wait, the silkscreen labels it with an L number, not a C number (or an R number).  This might be an inductor instead?

 

Yeah, I think it's an inductor. Symbol matches for inductor.  Looks like I will need and LCR meter, and a 1k resistor.  (then look for an identical inductor on the board, and test it)

 

Then I will know what to put there.

 

Did that 1K resistor test bad?

 

Another suggestion is to ohm-out where that inductor goes and maybe even compute the value if it's a simple filter. Wonder if it goes to a power rail on the slots?

 

There have been times were I've hacked in a plain old jumper short to get stuff running. Ideally you will of course want a calculated or measured value here.

Share this post


Link to post
Share on other sites
1 minute ago, OLD CS1 said:

I have a dual-CPU board with ISA slots, SCSI, two 233MMX, and 32MB RAM.  Wonder what that could get these days.

Some dual CPU boards are quite collectible, and all of them are worth saving. A Tyan Tomcat dual Socket 7, for instance, is a board that would go for over $200.

Share this post


Link to post
Share on other sites
Posted (edited)

I've been offered upwards of $225 for a basic VS440FX Pentium-Pro mobo. And $150 on a Micronics C200 AMD K6-2 mobo. Still have them.

 

Commodity or not. The rolling window will catch up to and move over the Pentium II, III, IV and dual-core E series stuff. Then it will move on to the first Ivy Bridge examples. And just keep rolling and rolling.. By then we'll all be dead and our vintage computers will either be in the dump or the museum.

 

While we're on this topic I'd suggest people buy up spare parts for whatever system(s) they got. I got some spares for my sentimental 486 rig. I started looking on ebay for parts in 2008'ish and first last year was I able to get a spare motherboard - and it needs some repair still.

 

The semi-proprietary memory expansion card. Saw on on ebay in 2015, got it for $29.95. Never seen either again. And not likely will.

 

I say it's semi-proprietary because it only works for the motherboard it was made for. A custom design to be sure. But it only has a few generic latches and gates. It could be reproduced quite easily, aside from the busywork and time of layout and machining a board. What's it got, like 8 LSsomething parts + SIMM sockets.

Edited by Keatah

Share this post


Link to post
Share on other sites

The best P3 boards already command a premium. Several years ago, you could buy Intel 440BX-2 ("Seattle") mobos new in box for about $40. Now used examples of that board can reach $100.

 

That era peaked with the P3 Tualitin boards, and enthusiasts also use Socket 370 and Slot 1 Slotkets to get Tualatin tech on boards that still have ISA.

 

As a rule of thumb, the last boards (that is, the most recent) that offer a particular technology (usually bus) are collectible. The last ISA boards. The last AGP boards. Same goes for the cards (e.g., last, most powerful AGP card).

Share this post


Link to post
Share on other sites
1 hour ago, boxpressed said:

The best P3 boards already command a premium. Several years ago, you could buy Intel 440BX-2 ("Seattle") mobos new in box for about $40. Now used examples of that board can reach $100.

 

That era peaked with the P3 Tualitin boards, and enthusiasts also use Socket 370 and Slot 1 Slotkets to get Tualatin tech on boards that still have ISA.

Last I checked was when I bought a box of 10 (a real intel sku) whitebox Seattles. $15 per board. 175 shipped. My sentimental "collectible" PIII is a slocket rig.

 

My first PII/III build was a PII-266 on an AL440LX board. A first iteration of the LX/BX chipset from a time when PCI graphics cards were faster than AGP 1X.

 

1 hour ago, boxpressed said:

As a rule of thumb, the last boards (that is, the most recent) that offer a particular technology (usually bus) are collectible. The last ISA boards. The last AGP boards. Same goes for the cards (e.g., last, most powerful AGP card).

Indeed. It's when the bugs are worked out. It's when the tech is at its pinnacle and most feature rich. And this applies to many other things.

 

But beware of last-minute budget entries or cost-cutting attempts. Like the GF4 4800 vs 4600. Or the crap GF4-MX stuff. But in this case the 4800 eeks a few fps more due to agp 8x. But it was never implemented on deluxe VIVO cards that also sported S-Video, DVI, and VGA, such as the all-in-one like the Gainward GeForce4 TI4600 PowerPack! Ultra/750 XP TV/VIVO Golden Sample 128MB yes that was the real name as printed in catalogs and price listings. My original card blew up, but I was quick to purchase another one and a spare. That back in 2009'ish. Saw one move in 2014 at over $400-$450. Haven't seen them since.

 

Another example of best and last of the breed in video cards was a TNT2. Going by a more reasonable name of ASUS AGP-V3800 Deluxe.

 

So..Anyways.. To me a real legacy board must offer 2x ISA slots, 1x parallel, 2x serial, 2x Floppy, and 2x IDE connectors at the minimum.

Share this post


Link to post
Share on other sites
6 hours ago, Keatah said:

 

Did that 1K resistor test bad?

 

Another suggestion is to ohm-out where that inductor goes and maybe even compute the value if it's a simple filter. Wonder if it goes to a power rail on the slots?

 

There have been times were I've hacked in a plain old jumper short to get stuff running. Ideally you will of course want a calculated or measured value here.

 

It's being shipped from Ukraine, so could take awhile to get here.  I was attempting to try and get some idea of what I need to fix it, so I can hit the ground running when it gets here.  Considering the size and kind of package, there's a small range that the device could be-- Anywhere from 1uH to 20uH, seems to be the typical values in that form factor. Larger inductances tend to not be ceramic packages. 

 

I believe you are correct that this is a filter to suppressing ripple on the ISA slot's voltage rail.  Given the very low inductances typical of that package form factor, a small bit of iron wire would probably work... but I would ideally like to put a proper discrete ceramic inductor of the correct value there.

 

Again, I don't have any ISA cards that I can't live without, aside from my SB32AWE, but I dont want to put that in a "potentially iffy" ISA bus. PCI is all I really need.

Share this post


Link to post
Share on other sites
Posted (edited)

I bought an entire Socket 7 PC with an AMD K6 200Mhz with 32MB of RAM for $20 a few years back. It was pretty much a complete system, just needed a HDD to boot. 

Edited by DragonGrafx-16

Share this post


Link to post
Share on other sites

It is what it is...

 

I have a small surplus of old PCI devices floating around.  A handful for 72pin SIMMs, and am already a proud owner of an SD->IDE adapter (which cannot handle larger than 128gb modules, verified. Cannot do 48bit LBA.)

 

Mostly, I just need an ATX->AT power supply converter (they exist!), along with a CPU, then I'll be golden.

 

 

Share this post


Link to post
Share on other sites

I bought the Startech AT 230 watt power supply for mine as the old one that came with the system kept shutting off randomly sometimes...

 

The Startech one is really the only decent AT PC supply still being made.

Share this post


Link to post
Share on other sites

I picked up two AT power supplies a while back from Tiger Direct.  I have to go look to see what brand, but they are both about 8 years old, I think, and the only thing to go wrong with them is the fan.  Originally I was rotating them out, but now I just quickly replace the fan when it seizes and keep the other as a spare.  These run my Solaris x86 server on an AMD K6-III+.

Share this post


Link to post
Share on other sites
Posted (edited)

The board itself has arrived.  The size is very small indeed for an inductor. Very likely in the 1 to 3 uH range.  I am just not terribly sure how to reverse-derive the proper inductance for this circuit.  I would need to know the capacitance of the nearby cap, and it is not listed.  I really do not have the appropriate equipment to determine its capacitance, and even if I did, it would mean removal of a surface mount component for testing.

 

Does anyone have any bright ideas, or should I just wing it, say "Screw it", and put a 1.5 to 2uH discrete inductor on there?

 

 

There are 2 other discrete inductors on the board.  Both are a straight wire patch, with a 5mm dia, 1.5cm long tube of ferrite surrounding it.  They seem to serve vastly different purposes though;  One is situated near the keyboard connector, the other near the motherboard's P4 and P5 connectors.  Both are likely to be power noise filtration components, but for different kinds of hardware.  I could probably derive their values from the measurements of the size of the ferrite core they run through, and the diameter of the wire used.  They are approximately the same size as the pin positions for the thru-holes for the destroyed ceramic SMD inductor.

 

 

Edited by wierd_w

Share this post


Link to post
Share on other sites

Trace it out, where’s it go to, where’s it coming from? How is it hooked to the cap? And what ISA pin number it connect to.

 

Then we can get to work.

Share this post


Link to post
Share on other sites
Posted (edited)

I need to recharge the battery in my multimeter. (I use a NIMH rechargeable 9v, since I have a suitable charger, and live in the boonies, and hate going to the store to get new ones when I need to use the multimeter) 

 

I will let it do its thing, then do quick spot tests against all the contacts in the isa slots, against the "downstream" end of this blown component.  The board itself is clearly a multilayer PCB, with hidden traces, so visual inspection does not work. (It looks like the trace just ends at the thruhole, and I know that is not the case. That is not how inductors work, and certainly not how one explodes.)  Multimeter tracing is the only real option.

 

Give me an hour or two to recharge the battery in the charger. Then I'll start probing.

 

Cursory visual inspection shows that the trace comes from some unknown part of the board, (ISA slot presumed due to proximity. It does not make a lot of sense to route a trace all over the universe.) goes through the blown inductor, then has the capacitor of unknown value off the end of that, and the common ground.

Edited by wierd_w

Share this post


Link to post
Share on other sites

If we can't get any good tracing, then the other option is guess and see what happens. Or write to gigabyte and have them ID the part, if they'll do it.

 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...