I have this board too, but also without cache card or vram upgrade. I've not seen the cache card for this appear at all on ebay in the last few years.

Doe anyone have a list of the replacement cap values? My board is currently capless due to them leaking but I was never 100% sure from the markings what I should be replacing them with...

b_riera wrote on 2023-12-07, 03:59:

Again, sorry for the length. Don't want to hijack your thread but figured I'd give you everything I've learned since I started with this machine two months ago.

This is fantastic, thanks so much for all of your work in putting this together! And it will surely help someone down the line (there are dozens of us!). This is exactly the the post I was looking for a few days ago.

I appreciate the warning about the caps. I'll do a good visual inspection today when I install the sound card, but will have to address this regardless.

For my board and bios revision (A03 I think?) I was able to stick in a Western Digital 40 GB IDE drive. The bios wouldn't autodetect it but when I tried the option for the biggest drive (I think 504 mb) it read and I was able to install a DOS partition. So now I have 527 mb of total disk space, works for me.

** While we're all here, do you know anything about the power supply? I have a Lite On PA-4151 D 146 watt supply installed. I think it might be on the fritz as it doesn't always spin up my hard drive in time at boot. Would a standard AT supply work here? Or is there more Dell proprietary nonsense? I hope it's the former! **

rasz_pl wrote on 2023-12-07, 08:42:

same part number because its for your ET4000 board, you can tell by same keying, wont even fit in OPs motherboard 🙁

You just saved me $60, thanks! I see what you mean with the keying, thanks for pointing that out. Looks like I'll stick with what I have (I was hoping when setting out on this path to just recreate my childhood experience with a 386 33, or maybe get a 486 like my friend's computer I envied). This fits. 512 kb should be fine for DOS gaming I think? I'll probably never find the cache card. Thanks again for your help, and good luck figuring out your obscure Dell equipment as well.

rasz_pl wrote on 2023-12-07, 08:42:

it looks to be keyed for your board with ET4000, OPs board has S3 805.

This truly confuses me as the listing says it's pulled from a system with S3 graphics but yeah, on closer inspection it is keyed identically to the Tseng upgrade and definitely not what I saw in the photo of the OP's motherboard. How annoying!
My newer board uses 2x 34 pin connectors for an extra 1MB and there's a Dell 486 with an ATI Mach 32 chip that uses the exact same looking memory upgrade board yet it's keyed differently yet again. Not wasting money on it to possibly fry my board experimenting.

rasz_pl wrote on 2023-12-07, 08:42:

Did you happen to stumble upon any data on Dell PowerLine 450DE/2 DGX Graphics Workstation (also called JAWS) system while doing research by any chance?

Ha yes I did but barely. You've found much more info than I did. I could only find some user manual for the motherboard and noticed it had an EISA riser in a very perplexing mount yet it used the same cache card the Optiplex (later board type does).

sirlemonhead wrote on 2023-12-07, 12:25:

Doe anyone have a list of the replacement cap values?

Seeing as I just did this job last week, yes.

This is for the older board revision I've mentioned before. Mine has Tseng video although looking at the photo of the OP's board, they otherwise look identical. Note: the newer board with a different layout has completely different capacitor values.
All capacitors are 4mm SMD electrolytics (sometimes referred to as size B)

10u 16V - x10
22u 16V - x6
3.3u 50V - x17

If you want detailed photos of sections of the board so you know where they go exactly, PM me and I'll send them. No use clogging up this thread unless everyone wants them.

mr_noun wrote on 2023-12-07, 14:12:

I appreciate the warning about the caps. I'll do a good visual inspection today when I install the sound card, but will have to address this regardless.

For my board and bios revision (A03 I think?) I was able to stick in a Western Digital 40 GB IDE drive. The bios wouldn't autodetect it but when I tried the option for the biggest drive (I think 504 mb) it read and I was able to install a DOS partition. So now I have 527 mb of total disk space, works for me.

** While we're all here, do you know anything about the power supply? I have a Lite On PA-4151 D 146 watt supply installed. I think it might be on the fritz as it doesn't always spin up my hard drive in time at boot. Would a standard AT supply work here? Or is there more Dell proprietary nonsense? I hope it's the former! **

Seriously, the newer board looked immaculate with no leaking caps or funny smell but probably 75% had leaked but not enough to become visible.

Interesting that you could use a big HDD. On both my boards with later BIOS revisions, I get an annoying "Hard Disk Controller Failure" every boot after about a minute of it hanging without an overlay or XT-IDE.

Mercifully the power supply is standard. Mine was dead on arrival (why I got the system so cheap) and I didn't feel like attempting a repair on an unknown and dead 30 year old PSU. I opted for a standard cheap ATX power supply and used a cheap ATX-AT adapter. They come with spade connectors to connect to the physical power switch on the front. I replaced the PSU's fan with a Noctua one and now my cheapo PSU is no longer noisy. Just to note with those cheap adapter you'll be missing the -5V rail unless you add regulation yourself but you shouldn't have a problem with a computer of this era. This has caused no problems for me with a Sound Blaster, SCSI card and NIC in there.

b_riera wrote on 2023-12-07, 16:22:

Interesting that you could use a big HDD. On both my boards with later BIOS revisions, I get an annoying "Hard Disk Controller Failure" every boot after about a minute of it hanging without an overlay or XT-IDE.

Thanks! Hmmm, come to think of it, this is the behavior mine does occasionally and I thought it was the PS, but it works well enough if I cycle the power a few times. I guess I could just use an overlay and fix the problem, though!

b_riera wrote on 2023-12-07, 16:22:

If you want detailed photos of sections of the board so you know where they go exactly, PM me and I'll send them. No use clogging up this thread unless everyone wants them.

It looks like as a new user I can't send PMs yet, but detailed pictures would be great! Also, were there specific % tolerances on the caps? Got Mouser pulled up right now.

Thanks for the cap info! I removed my capacitors a long while back and never got around to replacing them yet. I wasn't 100% sure what the markings on the caps meant but I've just found the list of the capacitors and locations I made back then and it's kinda obvious...

'10, 16v, 201'
'23p, 3.3, 50v'

I do have some noted as '23p, 22, 6v' but of course the voltage is fine with 16v alternative. And do they even make 6v caps?? I'm nearly sure I actually have the capacitors in a bag somewhere so I can double check...

My board has pads for alternative capacitors too - probably not worth putting tantalums on instead?

I'm also tempted to go down the route of getting the alternative board and picking up one of the more readily available cache cards...

mr_noun wrote on 2023-12-07, 17:48:

It looks like as a new user I can't send PMs yet, but detailed pictures would be great! Also, were there specific % tolerances on the caps? Got Mouser pulled up right now.

Here you go. First number on the capacitor is the capacitance value. As for tolerance? No idea what the originals were. I never figured it out. As low as you can within reason is always good but capacitors used for power decoupling really can be a fair bit off and it won't make a difference. At a quick glance, it seems that's what most of these on the board seem to be doing judging by their positioning near components and VCC traces on the board.I think I'm using 10% and 20% tolerance caps which is definitely on the meh side of things but both boards are completely stable. I haven't taken the time to try and figure out what each one is for but when I was testing things, I was using values way off and it made no difference. The capacitor I'm using for the RTC pulse is 1u when the original was 3.3u. The data sheet for the chip said a wide range of values were acceptable and the 1u works fine as it's what I had on hand. It's the through hole capacitor soldered straight on the board flat in one of the photos.

sirlemonhead wrote on 2023-12-07, 18:22:

My board has pads for alternative capacitors too - probably not worth putting tantalums on instead?

I'm also tempted to go down the route of getting the alternative board and picking up one of the more readily available cache cards...

That's right, I definitely remember 6V caps now. Won't make a difference going higher in Voltage rating as long as the package is the same size and fits as you know. Yeah I have those extra pads too. About half way through swapping them I kind of was wishing I went the tantalum route so I'd be one and done forever but there are two different sizes and I didn't feel like guessing the correct ones (probably could compare to my Dell 386 which uses them). Maybe in 20 years I'll do it!

And yeah, after collecting a second board for parts, it became my main board due to the cache card becoming available. I made a low ball offer on one on eBay and it was accepted! Just note that the single motherboard screw is in a different place depending on the board so you'll have to insulate that to not short out your new board. It's clipped in in various places so no fear of it moving without the screw. Then of course you have to remove a couple of tabs on the riser cage to accommodate the cache card.

Thanks for the info! I forgot the tantalum pads were different sizes! I'll have to take my board out again and have another look at it.

What Dell 386 do you have? a System 333P by any chance? 😀

sirlemonhead wrote on 2023-12-07, 18:52:

What Dell 386 do you have? a System 333P by any chance? 😀

It's a System 325SX w/ 4MB RAM unfortunately. Those 16bit bus 386SXs are dog slow though for game usage. Interestingly it is American built for a system sold new in Ireland. PSU is also 240V only but still works so it's useless to me here in 110V land. I'm not sure if the factory in Bray was producing Dells back that far but I am used to seeing Irish built Dell machines around the Pentium era onwards with a very proud Made in Ireland or Made in the EU sticker. I got it for free about 14 years ago. It was dumped in the back of some closet in an office in Dublin. The battery had leaked over the mouse port and ruined the traces so currently it's serial mice only. I haven't gotten around to repairing it but it looks doable now with my current skill level. We used it for a couple of years as a DOS based POS machine in our family cafe with a parallel Zip drive (for backup transfer to modern machines in case Revenue ever got curious!), a serial receipt printer, cash drawer and PS/2 barcode scanner. Faultlessly reliable otherwise. Would you believe I flew with it in my suitcase two months ago? It travelled from Wicklow to Pennsylvania as did half the parts for my current Dell 486.
I honestly have no use for it but didn't want to throw it out. I figured I would use it as a science experiment trying to replace the SX with a TI486 clock doubled 50MHz part at some point. Are you looking for anything in particular? The 240V PSU perhaps? I can try smuggle it back in my suitcase next time I'm home haha.

I'm looking for the cache card for the 333P but also actually after the shelf/bracket that the floppy drive attaches to the case with! As shown here: https://www.dropbox.com/s/u0vzzx4568z0qr8/fm4Xj52.jpg?dl=0 (another Vogons member was kind enough to take photos of theirs a few years back!)

I've owned the machine since 1992, my dad got it while working at Irish Life. It originally had the floppy drive in the 5 1/4 bay but I asked for a CD Rom and Soundcard for it around 1994 and the office installed those, moving the floppy (which I don't think is original as it doesn't colour match that dark greyish plastic on the front) down to the 3.5" space. They didn't have or install the mounting bracket so my floppy drive sits somewhat awkwardly in, screwed in on only one side with bits of cardboard sorta wedging it in place on the other side.

That's amazing you got such use out of your machine and carrying it in a suitcase? fair play! mine is heavy enough so assume yours is the same! My battery also leaked but only near some of the parts relating to the serial port I think - I haven't tested it since actually but it cleaned up well so I assume its ok. My original hard drive is working still - a 120meg Quantum Prodrive LPS - the sound it makes when seeking is fantastic and very nostalgia inducing. I really need to source a spare because I think I'll be upset if/when it dies, heh 😁

Mine had the exactish (maybe logo was different) monitor as the OP actually but unfortunately I was made dump it years ago 🙁 A big regret unfortunately.

Here's more or less how it looks now (despite being a 10 year old photo) https://www.dropbox.com/scl/fi/b2032dmgrmqwjq … ub3hlvxpee&dl=0

sirlemonhead wrote on 2023-12-07, 20:04:

I'm looking for the cache card for the 333P but also actually after the shelf/bracket that the floppy drive attaches to the case with! As shown here: https://www.dropbox.com/s/u0vzzx4568z0qr8/fm4Xj52.jpg?dl=0 (another Vogons member was kind enough to take photos of theirs a few years back!)

I would private message you regarding this but I can't send those yet. No idea what the post count is required. I can help you out with that bracket though. I just went into the basement there. Mine has the 5 1/4" bay occupied. Originally was a 3 1/2" drive off brown coloured and nothing in the 3 1/2" bay. The plastic cover would need to be replaced or cut to add a drive there.

Anyway to stay somewhat on the original topic, See the photo of my 486 like the OP's. That now has the 386's original 3 1/2" floppy along with a new old stock 5 1/4" 1.2MB drive. Originally it came with a combo drive which is now in the 386 as seen in the photo of that system. I like the look of the separate drives better.

Anyway, the bracket was unused in my system (excuse the state of it. It's in a dusty basement and hasn't been used in years). It has an extra plate screwed on the front which I guess was to stop you pushing through the front cover causing the plastic to bend. I removed it, put the system back together and I see no difference. It's yours if you want it. I'll probably be home next in 2 or 3 months.

Hi, bringing this thread back. I dropped in a DX2 66 CPU and it's made a noticeable improvement, very cool. A friend has a Pentium Overdrive 83, any idea if this would work? I think it would work for the socket but there aren't many jumpers to configure on the board so I'm not sure. Thanks!

I haven't tried that as I don't have one but it's documented by Dell that it works in these machines. I remember seeing it in the release notes for the latest BIOS update (A13/A17 depending on board revision) that they added POD support. You'll probably have to update the BIOS first to ensure it works properly.
Here's the fun part, I was about to drop the link here to the Dell support site page with the release notes and download but the link is dead! You can still find the result on Google though. Lucky for me it seems as I downloaded it in time. Seems Dell have been clearing house to end 2023. Should you need it, I have it. The filename is "4xxL_A17.exe". I've no idea what the policy is here about uploading files that should definitely not constitute any form of copyright infringement. It's an all-in-one update/notes program so you can't view the BIOS image file directly. You can update from the DOS prompt while booted from a hard drive which is nice though.

Wow, thanks! I can't find that update anywhere, so if it's possible to share it here I'd really appreciate it!

mr_noun wrote on 2023-12-17, 23:15:

Wow, thanks! I can't find that update anywhere, so if it's possible to share it here I'd really appreciate it!

It's the html thats gone rather than the file itself (follow the cached link instead in google to see this)...the file itself is still up at https://dl.dell.com/bios/4xxL_A17.exe

Thanks! That was easy.