momaka wrote on 2026-04-12, 19:14:

I wasn't identifying capacitors by their color and not sure where you assumed this from.

I think they might have misinterpreted my original post. I referenced the capacitors by color, because I marked them with different colors on the photo I posted. I simply wanted to have a way to reference which caps were which.

I think may have misunderstood that to think I was referencing the physical colors of the caps themselves.

I ended up placing an order with Digikey for polymer caps with a handful of different specs. I'm curious to measure them when I get them, especially to see what my ESR meter reports.

In the mean time, I removed all the 3300uF caps from the board and cleaned things up. It's ready for replacements.

I'm going to initially leave the 1500uF caps and test things to see if the board works. Depending on how that goes, I'll decide later if I want to also replace them.

I am interested to see what your results are with this. I recently picked up a small lot of scrap boards and one of them is a similar Socket 478 i845 chipset board with two ISA slots (not from DFI\ITOX though), and it definitely needs some caps replaced. The board looks to be in very very rough shape, but I'm hoping it isn't too far gone to repair. Either way, the price for the lot was low enough to make it worth trying to save it.

Also, I don't know if this is any help or not, but it looks like you can get DFI ITOX G4V620 boards (note: this one doesn't have a normal AGP slot) on Aliexpress right now and they are similar but have different caps on them... hard to tell what they are from the pictures. Can anyone tell what brand and series they are by the color?
https://www.aliexpress.us/item/3256805857528003.html

You can't really tell by the color, but I see the Lelon logo. Lelon's 85°C series (not suitable for motherboards, but I used them for audio) was blue, but they could have made other series the same color.

Ozzuneoj wrote on 2026-04-12, 22:10:

I am interested to see what your results are with this. I recently picked up a small lot of scrap boards and one of them is a similar Socket 478 i845 chipset board with two ISA slots (not from DFI\ITOX though), and it definitely needs some caps replaced. The board looks to be in very very rough shape, but I'm hoping it isn't too far gone to repair. Either way, the price for the lot was low enough to make it worth trying to save it.

What board did you pick up? Hopefully it's able to work again.

And I should know soon enough if my board is working. Digikey is usually pretty quick to ship things so I should have the new caps in a day or two.

Also, I don't know if this is any help or not, but it looks like you can get DFI ITOX G4V620 boards

Along those lines there is also the NIXSYS NX800 which looks like a clone of that DFI board. The NX800 uses all polymer caps. Unfortunately the available photos of it are too low resolution to make out any of the cap values.

Shponglefan wrote on 2026-04-12, 19:27:

momaka wrote on 2026-04-12, 19:14:

I wasn't identifying capacitors by their color and not sure where you assumed this from.

I think they might have misinterpreted my original post. I referenced the capacitors by color, because I marked them with different colors on the photo I posted. I simply wanted to have a way to reference which caps were which.

I think may have misunderstood that to think I was referencing the physical colors of the caps themselves.

Ah, yes, that indeed looks to be the case. Oh well. 😀

Shponglefan wrote on 2026-04-12, 20:40:

I ended up placing an order with Digikey for polymer caps with a handful of different specs. I'm curious to measure them when I get them, especially to see what my ESR meter reports.

Yeah, this should be a good exercise to see if your meter is calibrated correctly, more or less, as the new polymers should have capacitance pretty close to the nominal capacitance printed on the can.

Shponglefan wrote on 2026-04-12, 20:40:

I'm going to initially leave the 1500uF caps and test things to see if the board works. Depending on how that goes, I'll decide later if I want to also replace them.

And even if you do, you can keep them (the 1500 uF KZG) around as spare parts. Sometimes, I do temporary recaps with my pulled KZG caps that are still within spec.

lti wrote on 2026-04-13, 04:05:

You can't really tell by the color, but I see the Lelon logo. Lelon's 85°C series (not suitable for motherboards, but I used them for audio) was blue, but they could have made other series the same color.

Looks like that's spot-on right.
I initially thought the logo appeared like Ltec, but Ltec doesn't put a circle around their logo like Lelon does. Moreover, I looked at my datasheet collection for Lelon (courtesy of the cap datasheet depot on badcaps), and the only radial through-hole series from Lelon that have a blue sleeve are the REA series, which are indeed 85C general purpose type caps.
So yeah, not exactly the best choice for a motherboard CPU VRM output... but still way better than failed KZG. 😀

Lelon's are actually not that terrible of a brand either. I was fixing two electric room heaters last week with electronic control, and in both of them the Lelon caps were still in spec after 25+ years of operation in a pretty hot environment. Not bad of a run!

Shponglefan wrote on 2026-04-13, 11:24:

And I should know soon enough if my board is working. Digikey is usually pretty quick to ship things so I should have the new caps in a day or two.

Nice!

Digikey is pretty good... though the last times I shopped with them (back when I was still living in the US a few years ago), they were rather slow with the order. And it wasn't during particularly busy times of the year either (i.e. not Thanksgiving or Christmas.) Took more than a week both times to get my orders. Also tried expedited shipping once via UPS, and it took even longer, 🤣. Not that this would discourage me to shop from them again, though.

I recapped my Tualatin board a few years ago with polymer caps, going by the general rule that you can halve the capacitance of the electrolytics you're replacing due to polymers having much better ESR ratings. The VRM for the Tualatin isn't nearly as demanding as the VRM for a P4, but to this day, the board has been rock solid, no spurious BSODs or freezing. Very glad I went the polymer route.

Shponglefan wrote on 2026-04-13, 11:24:

Ozzuneoj wrote on 2026-04-12, 22:10:

I am interested to see what your results are with this. I recently picked up a small lot of scrap boards and one of them is a similar Socket 478 i845 chipset board with two ISA slots (not from DFI\ITOX though), and it definitely needs some caps replaced. The board looks to be in very very rough shape, but I'm hoping it isn't too far gone to repair. Either way, the price for the lot was low enough to make it worth trying to save it.

What board did you pick up? Hopefully it's able to work again.

I'm about 99% sure it is a BCM BC845DL.

The chipset heatsink has been removed and it looks like someone tried to rip the parallel port off and gave up after realizing how firmly attached they are (it is at now at an angle... 🤣 ... 😥). I'm thinking there's about a 30% chance that it won't have some kind of irreparable damage... such as a large chunk out of the PCB, many destroyed traces or (most likely) a chipped die on the north bridge, but I am hoping for the best. Socket 478 boards with ISA slots are not common, but finding one with a normal AGP slot as well is quite rare, at least without spending a few hundred bucks. There are a couple of other items in the lot so it won't be a total loss if this one is damaged in a way that I am not able to fix right now.

Over the last five years or so I have picked up so many repair skills that I never thought I'd have... so if the north bridge is cracked I will probably still hang on to it just in case I have the means of replacing that too some day.

momaka wrote on 2026-04-13, 16:17:

Digikey is pretty good... though the last times I shopped with them (back when I was still living in the US a few years ago), they were rather slow with the order. And it wasn't during particularly busy times of the year either (i.e. not Thanksgiving or Christmas.) Took more than a week both times to get my orders. Also tried expedited shipping once via UPS, and it took even longer, 🤣. Not that this would discourage me to shop from them again, though.

I'm surprised they had taken that long. They seem to ship to Canada only using Fedex and usually only take 1-2 business days.

Only order I had take a few weeks was Hakko soldering tweezer tips that weren't in stock.

Ozzuneoj wrote on 2026-04-14, 00:57:

The chipset heatsink has been removed and it looks like someone tried to rip the parallel port off and gave up after realizing how firmly attached they are (it is at now at an angle... 🤣 ... 😥). I'm thinking there's about a 30% chance that it won't have some kind of irreparable damage... such as a large chunk out of the PCB, many destroyed traces or (most likely) a chipped die on the north bridge, but I am hoping for the best. Socket 478 boards with ISA slots are not common, but finding one with a normal AGP slot as well is quite rare, at least without spending a few hundred bucks. There are a couple of other items in the lot so it won't be a total loss if this one is damaged in a way that I am not able to fix right now.

Over the last five years or so I have picked up so many repair skills that I never thought I'd have... so if the north bridge is cracked I will probably still hang on to it just in case I have the means of replacing that too some day.

That sounds like some rough damage. It's really frustrating scrappers just trash boards like that.

Even if it doesn't end up working, still might be worth keeping for parts salvage to possibly repair another board.

Digikey order arrived this morning.

I did some more ESR testing and was still getting somewhat high ESR values of 0.04Ω to 0.05Ω even on the new poly caps.

I then decided to run the probe compensation adjustment on the ESR meter. After doing this, it reported more accurate ESR values.

The non-leaking 3300uF KZG capacitor still showed high capacitance (~4400uF), but only 0.01Ω ESR.

The 3300uF Panasonic FR capacitor now read 0.02Ω ESR.

And finally one of the Wurth polymer capacitors showed a dead-on 1500uF capacitance and 0.01Ω ESR.

I suppose if I want more accurate ESR values I'll have to get a more expensive ESR meter, but for my purposes the Atlas ESR70 is probably good enough.

Next up, I installed the Wurth 1500uF 6.3V polymer capacitors.

After some initial powering on with no components just to make sure nothing was going to explode, I installed a 2.8GHz P4, RAM, graphics card and POST card.

I initially tried with the ATI Radeon card I was using with my IMB200 motherboard, but the DFI board refused to boot with that video card. So instead I tried a GeForce MX440 AGP card and it successfully posted!

Initial testing was good. Ran a few benchmarks and nothing froze or crashed.

I even took a thermal image just to make sure nothing was overheating. New caps were between 29-30C.

AGP issue, that may bring suspicion on the caps around the AGP slot, even though the regulators appear to be linear rather than switchmode, transistors but no coils

I was wondering if the issue might have been that the ATI card (Radeon 9200) is AGP 8x and the board's chipset (Brookdale) is only AGP 4x.

Although the MX440 is reported to be AGP 8x and it works, so I dunno.

Shponglefan wrote on 2026-04-14, 15:37:

Ozzuneoj wrote on 2026-04-14, 00:57:

The chipset heatsink has been removed and it looks like someone tried to rip the parallel port off and gave up after realizing how firmly attached they are (it is at now at an angle... 🤣 ... 😥). I'm thinking there's about a 30% chance that it won't have some kind of irreparable damage... such as a large chunk out of the PCB, many destroyed traces or (most likely) a chipped die on the north bridge, but I am hoping for the best. Socket 478 boards with ISA slots are not common, but finding one with a normal AGP slot as well is quite rare, at least without spending a few hundred bucks. There are a couple of other items in the lot so it won't be a total loss if this one is damaged in a way that I am not able to fix right now.

Over the last five years or so I have picked up so many repair skills that I never thought I'd have... so if the north bridge is cracked I will probably still hang on to it just in case I have the means of replacing that too some day.

That sounds like some rough damage. It's really frustrating scrappers just trash boards like that.

Even if it doesn't end up working, still might be worth keeping for parts salvage to possibly repair another board.

Well, the board arrived and I'm happy to say that it is disgusting, cruddy and has bent up parallel and ethernet ports, as expected... but the northbridge die seems intact, I don't see any obvious PCB damage and none of the chips have bent legs! So, there is hope!

It is absolutely covered in caps though, many of which are SMD aluminum ones in tight places which are going to be a pain in the butt to replace. I wish they'd all just been through-hole parts... but oh well.

Some time I will give this a good cleaning and hopefully that will tell me how bad off it really is. With boards like this that have definitely been exposed to the elements for an extended period I don't trust the caps at all, and they tend to have a lot of crud collected around the tiny SMD components. I'm hoping none have been corroded or otherwise compromised by leaking electrolyte from the caps or something.

This is going to be a fun one and will have to wait until I am less busy. 😁

Ozzuneoj wrote on 2026-04-18, 00:20:

Well, the board arrived and I'm happy to say that it is disgusting, cruddy and has bent up parallel and ethernet ports, as expec […]
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Well, the board arrived and I'm happy to say that it is disgusting, cruddy and has bent up parallel and ethernet ports, as expected... but the northbridge die seems intact, I don't see any obvious PCB damage and none of the chips have bent legs! So, there is hope!

It is absolutely covered in caps though, many of which are SMD aluminum ones in tight places which are going to be a pain in the butt to replace. I wish they'd all just been through-hole parts... but oh well.

Some time I will give this a good cleaning and hopefully that will tell me how bad off it really is. With boards like this that have definitely been exposed to the elements for an extended period I don't trust the caps at all, and they tend to have a lot of crud collected around the tiny SMD components. I'm hoping none have been corroded or otherwise compromised by leaking electrolyte from the caps or something.

This is going to be a fun one and will have to wait until I am less busy. 😁

That sounds moderately hopeful. If all ICs are intact and working and the PCB isn't damaged, that's hopefully a straightforward restoration.

Would love to see it once you get a chance to work on that board! We need more P4 industrial boards showcased on this forum. 😁

Small update on the G4E620-N motherboard.

I removed and tested the four 1500uF 16V KZG caps. They all tested at around 1620uF and 0.01Ω ESR.

I could have probably just left them in. But since I had removed them, I replaced them with some 820uF 16V Wurth polymer caps. Board booted just fine afterwards.

Shponglefan wrote on 2026-04-18, 17:13:

Small update on the G4E620-N motherboard. […]
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Small update on the G4E620-N motherboard.

I removed and tested the four 1500uF 16V KZG caps. They all tested at around 1620uF and 0.01Ω ESR.

The attachment KZG 1500uF capacitor ESR measurement.jpg is no longer available

I could have probably just left them in. But since I had removed them, I replaced them with some 820uF 16V Wurth polymer caps. Board booted just fine afterwards.

The attachment DFI ITOX G4E620-N polymer capacitor replacements 2.jpg is no longer available

I ran into this same thing a month or two ago. While most KZG caps were very very prone to leaking, 16v KZG caps seem to have not been a part of the plague and tend to be okay. I believe the ones I found on a board were 1500uf as well.