FIC VA-503+ best replacement for Vcore caps

[Majestyk]

I still have some old Socket 7 systems running for fun.
One of them has a FIC VA-503+ Rev. 1.2 Baby ATX board working, which was quite popular back in the days (ca. 1998).

The Vcore section has 6 "Canicon" 1500uF 6.3V which I don´t trust at all.
So I´m going to replace them soon.

The diameter of the Canicons is 8mm and the height is 16mm. I could use 10mm diameter but the hight is strictly limited since the CPU heatsink covers that area.

What I found so far:

1. Nichicon LG polymer 1200uF 6.3V 8mm x 12mm (would fit perfectly but only 1200uF)

2. Panasonic OS-CON polymer 1500uF 6.3V 10mm x 13mm (are slightly too fat, height is perfectly o.k.)

3. Rubycon ZLH 1500uF 10V 10mm x 17mm (slightly too fat, height at the upper limit, but would probably fit)

Which capacitor is the best choice? Can someone suggest a better alternative?

And please don´t mock me for using such an old legacy shit - it´s pure nostalgia...

[stj]

Re: FIC VA-503+ best replacement for Vcore caps

very good board - i still have one in a backup box.

[Majestyk]

Re: FIC VA-503+ best replacement for Vcore caps

Sure is!

The FIC VA-503+ and the EPOX MVP3G5 used to be my favourite boards back then since they were faster than the competitors´.

And here´s a Picture of the CPU-area:

[stj]

Re: FIC VA-503+ best replacement for Vcore caps

damn i always wanted that cpu,
i had to make do with a k6-2 500

too bad the usb 1.0 was a broken standard
it was the first board with usb, and got stung because of it.

[Majestyk]

Re: FIC VA-503+ best replacement for Vcore caps

The Intel HX chipset also had USB at a very early stage, I think even before VIA MVP3 but only some manufacturers assembled the headers to connect USB devices due to serious problems.

The AMD mobile CPUs (II+, III+) were available for a short time only and most distributors didn´t sell them. First everybody waited for these CPUs to be finally released and a couple of months later everybody was told they were no longer available.

You can still use these systems today as Long as you stay away from browsing flash-crammed websites. I use them for Office Outlook etc.
I even installed Windows 7 on one of These rigs last year. It was not fast but usable but Windows 2K and XP are best.

[lti]

Re: FIC VA-503+ best replacement for Vcore caps

There are lots of 8mm diameter 1500uF caps, but they are 20mm tall. I don't know where to find 16mm tall caps, but they were common in that time period. My old Compaq socket 7 motherboard also has 1500uF 6.3V caps in that size. It looks like your board was made for 10mm diameter caps in the three positions closest to the ISA slots.

I was thinking of getting one of those mobile CPUs, but I didn't want to modify the BIOS on the weird Compaq motherboard. It only officially supports up to 400MHz K6-2s, but a 500MHz CPU will work. The Windows-based diagnostic tool fails the CPU test because of the higher clock speed.

I also have a dead socket 7 motherboard with an Intel chipset and USB ports. It is an ATX board and only supports SDRAM.

[Dan81]

Re: FIC VA-503+ best replacement for Vcore caps

My old Compaq socket 7 motherboard also has 1500uF 6.3V caps in that size. It looks like your board was made for 10mm diameter caps in the three positions closest to the ISA slots.

I was thinking of getting one of those mobile CPUs, but I didn't want to modify the BIOS on the weird Compaq motherboard. It only officially supports up to 400MHz K6-2s, but a 500MHz CPU will work. The Windows-based diagnostic tool fails the CPU test because of the higher clock speed.

What motherboard does it use?If it's Soyo or Gigabyte then you can try using their BIOS instead of the Compaq BIOS.

[lti]

Re: FIC VA-503+ best replacement for Vcore caps

I don't know who made it. It is one of those boards that has all of its expansion slots on a separate riser card. It was only used by the Presario 2200 and 2400 series computers.

[Majestyk]

Re: FIC VA-503+ best replacement for Vcore caps

So, what I did is replace the 5 x 1000µ at the 5V rails with Rubycon ZLH 1000µ 16V, replace the two 1500µ 6.3V at the step-down converter for 3.3V (RAM / AGP) with Panasonic OS-CON Polymer caps and replace the Vcore caps (for stabilizing Vcore) with 1500uF OS-CON Polymer, where there is enough space (10mm) and 1200uF Nichicon LG Polymer whrere there´s only room for 8mm.

I think this is a workable compromise. It´s no use to force a 10mm in there when you cannot open the lever of the ZIF-Socket anymore...

Now there are about 20+ 10uF left that are spread over the board. I´m probably going to swap them as well.

[lti]

Re: FIC VA-503+ best replacement for Vcore caps

That might be the only socket 7 motherboard with polymer caps. It should work pretty well.

My Compaq uses the same CPU voltage regulator circuit, but it only has four 1500uF caps on the output and it might have a larger output voltage range (2.0V to 3.5V).

[stj]

Re: FIC VA-503+ best replacement for Vcore caps

damn, if i tried to do that it would cost more than the board!
where are you getting cheap poly's?

[Majestyk]

Re: FIC VA-503+ best replacement for Vcore caps

Well I wouldn´t say cheap, but if you order a couple of hundreds as i do from time to time they are about 80 or 90 Eurocent each.
Here I "spoilt" 8 polymers, the rest is all ZLH Rubycons.

I also replaced the 20 10uF today so it´s "total recap" for this board...
Next week will show if it´s running stable.

[Majestyk]

Re: FIC VA-503+ best replacement for Vcore caps

And here´s the finished FIC VA-503+

[c_hegge]

Re: FIC VA-503+ best replacement for Vcore caps

Nice. That board won't know itself.

[stj]

Re: FIC VA-503+ best replacement for Vcore caps

your still using the AT keyboard connector!

i desoldered mine and the mouse header.
there are holes in the board under them to fit standard PS2 sockets.

[Majestyk]

Re: FIC VA-503+ best replacement for Vcore caps

Yep - still using it.
The old AT-cases in my inventory all have fixed cutouts for the DIN connector only. So I use a DIN-PS2 adaptor. Otherwise I would have to dremel the cases...
It´s a pain to find the right PS2 slot brackets for the mouseconnector sometimes since the pinouts on the mainboards are proprietary and vary between manufacturers.

[stj]

Re: FIC VA-503+ best replacement for Vcore caps

pci-usb2 card and usb mouse would be my option.

[Majestyk]

Re: FIC VA-503+ best replacement for Vcore caps

This can be an option if the PCI-Card and the controller chip is supported by the BIOS. I made good experiences with VIA USB controllers and encountered severe problems with ALI.

If you have to fiddle with the BIOS settings you´re back to PS2 since the USB keyboard isn´t ready before the OS has been loaded.

Those old Socket 7 (and older) boards are true Divas...

[lti]

Re: FIC VA-503+ best replacement for Vcore caps

I tried putting a really cheap Rosewill USB 2.0 card with a VIA controller in the Compaq. The CPU usage wouldn't go below 20% with the card installed and was stuck at 100% while transferring files to a flash drive. The onboard USB ports (controlled by the SiS 5598 chipset) were faster.

[momaka]

Re: FIC VA-503+ best replacement for Vcore caps

Polymers on a Socket 7 board? -That is one epic recap job!

If you need a keyboard with a DIN connector, let me know. Last time I checked, we had one in the "free" pile in one of our electronics classrooms at the university. I think it also had true mechanical keys with springs. Oh, and a flip-over type plastic dust cover, too .