Then it's probably a black block RTC - difficult to replace if not socketed...
Maybe it had an external battery too which is now missing.
But make a photo of the board so we can see.

Here's a closer look at the mobo...
If you want me to try and spot anything in particular, which isn't clear on the photo, please ask! 😀
Sorry, my camera is cheap and crappy. It doesn't do macro for instance.

the card for the DVD and the power supply cables are blocking the sight.

h-a-l-9000 wrote:

the card for the DVD and the power supply cables are blocking the sight.

I just examined that area. I found jumper J2. Then I looked at this diagram -

http://stason.org/TULARC/pc/motherboards/E/EL … 6-UC4914-G.html

Just north of the keyboard, is J2. It is for "external battery".

Observation: J2 looks like a typical 4-pin arrangement. However, one of the pins is not present. On the board, it looks like this -

J2
I
X
I
I

Where I = a pin, and X = a "sawn off" / missing pin.

Am I in luck? Would fitting an external battery be possible? I am guessing that this would work OK.

Thanks a lot for your help! 😀

TULARC has an entry for this board, it's an Elitegroup UC4914-G. Unfortunately the schematics don't have the location of the battery, but they mention an external battery connector (J2) near the power- and the keyboard connector. The battery is probably somewhere nearby.

EDIT: Ah, you already found it. did you spot the battery as well?

...hmm, what a whole lotta crap you've collected...heh 😁

Anyway, check out this, 'J2' should be the battery connector:
http://www.stason.org/TULARC/pc/motherboards/ … 6-UC4914-G.html

Most likely powered by one of these originally:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem … em=310103700715
At least my 486/33sx is.

(but be warned, most of the batteries of this type are ancient, even if new - made in the 1990's, should have a date code(mm-yy) printed on them, ask seller if curious)

Edit: I notice you found the mobo specs...

.

PS: they claim they are rechargeable, but on the battery itself it is written 'do not recharge'... well...

Anyway, here's one that may or not work - looks like replaceable battery:
http://cgi.ebay.com/NEC-Tadiran-3-6v-Lithium- … A1%7C240%3A1318

old one:
http://cgi.ebay.com/3-6VDC-Lithium-3-6-Volt-D … 1QQcmdZViewItem

replacements:
http://www.smallbattery.company.org.uk/sbc_tl-5242w.htm
http://www.alllaptops.co.uk/ps/t/TL5242-W.htm

.

5u3 wrote:

EDIT: Ah, you already found it. did you spot the battery as well?

Hehe, I'm still looking for it. 😊 Pity it's not labelled "battery"! 😉
It's not urgent. The mobo appears to be functioning OK, and I'm happy to try out an external one - I've never done that before, so I'd be keen to check that out. 😀

bestemor wrote:

...hmm, what a whole lotta crap you've collected...heh 😁

Some of it's quality crap! 😀

Thanks a lot for those links! Awesome! 😁

This mobo keeps changing speed from 66mhz down to a really painfully slow 16mhz. I've changed the intel 486 dx2-66 chip, but this problem still persists. Do you think it's to do with the low CMOS battery warning I saw the other day?

On the mobo, there is a jumper labelled turbo sw, which has nothing at all on it. I guess this is for a switch. I've tried poking at it with a screwdriver (when the machine is running), to short it (and make a connection), but ATM, I'm unsure whether this is having any effect or not. (I can only tell if the speed has changed when I reset the machine and observe the BIOS POST message appearing on the screen, where it either says 66mhz or 16mhz.)

Many thanks for any comments. 😀

Put a jumper over the turbo switch connector (to simulate the switch is on), and see if the CPU is reported correctly.

5u3 wrote:

Put a jumper over the turbo switch connector (to simulate the switch is on), and see if the CPU is reported correctly.

OK, done! (I'll keep an eye on it...so far, so good! 😀 Thanks very much for the tip!)

retro games 100 wrote:

My new rig works! :shocked: […]
Show full quote

My new rig works! 😳

I think it's a 486 dx2-66. The mobo says: UC4914-G, Rev 1.0

I'm really pleased this thing works. 😁 I gave up with the 'evil acid box'; it's only worthwhile purpose now is to supply the juice to the new mobo. I couldn't be bothered to wrestle with the HDD stuck inside the packard bell, so that stayed put.

For the dvd-reader, I am using an ISA based Acculogic s/IDE2 CD-ROM controller card. For the HDD & floppy drive, I've stuck those on to a VLB multi i/o card.

Having spent 3 whole days with a dodgy FIC board and the aforementioned evil acid machine, this health and safety extravaganza took less than 30 minutes to get running. I was stunned that I got this one right first time.

I've just got one query for now - when I powered up this beast for the very first time, it warned me of a low cmos battery. I've looked on the mobo, and I cannot spot either an evil chunky battery, or a button battery.

Hi there mate 😀 I know this thread is a million years by now, probably you don't even have that 486 anymore... Anyway, I just got one of these boards up and running myself, so just wanted to give some input for future reference.

retro games 100 wrote:

I've looked on the mobo, and I cannot spot either an evil chunky battery, or a button battery.

I'm not 100% certain if this is the original battery, but it very much looks so:

Here's the battery connector on the motherboard:

About the board reporting 16MHz CPU speed, I've also encountered this with the turbo button switched ON. It appears to happen when restarting the computer without first shutting it down. Deactivating and reactivating turbo when the OS's fully loaded doesn't work at all. I also run an Intel DX2-66 in my system.

One final thing: if you had a CT2290 ISA in your rig, and noticed the FDD wouldn't work at startup... swap for something else. From my experience, the CT1740 ISA would cause the same trouble for a while, but with the FDD jumping back to life after ~30 seconds. Starting the machine with no sound card at all would always make the FDD happy to run. Just a tip if someone else encounter this problem. 😀