Jumpers all set correctly? What about CMOS? Try different RAM and cache?

The CPU jumpers were all set according to TH99 docs and the board's own tables, can't think of anything else having to do with them 😒 Tried various pairs of RAM to no avail, however no CMOS clear done yet. Also I don't know the status of the cache chips, will test them elsewhere tomorrow and report back. Thanks!

Is this the manual? You could cross-check settings.
I know it is of bad quality, though it's the only one I can find.

http://www.elhvb.com/mobokive/Archive/Ecs%20- … ual/um8810p.zip

Another forum member has this board and got it stable. =My Cyrix 5x86 systems : 120MHz vs 133MHz=

psychz wrote:

Been trying to set up an ECS UM8810 board with a 486DX/33, but it doesn't seem to pass its self-checks. PhoenixBIOS code seems to be 1-3-4-1, "Test 512 base address lines". Any insight on what this actually means? The CPU is tested working on another Biostar mobo. (Actually I think this error code has to do with memory?) Is the board dead/fixable?

Yes, you are right, it means bad RAM.
It is telling you to test the first 512k but that's a logical address (so the wording "base address lines") not the physical address.
I myself am clueless as to how to get from a logical address to a physical address....

If RAM has been been in a socket for ages sometimes an oxide layer builds up in the connections. (Yes, even gold oxidizes a little over time.)
If that's the problem removing and reinstalling the RAM a few times will rub the oxidation off where it matters and it will work again.

If that doesn't do it then try a different RAM module.
.

Related "Fun Fact".
The US Navy, because their equipment has to deal with salt-air, usually chooses silver over gold for electrical contacts.
Why .... Silver oxide is almost as conductive as silver.
.

PCBONEZ wrote:

Related "Fun Fact". The US Navy, because their equipment has to deal with salt-air, usually chooses silver over gold for electri […]
Show full quote

Related "Fun Fact".
The US Navy, because their equipment has to deal with salt-air, usually chooses silver over gold for electrical contacts.
Why .... Silver oxide is almost as conductive as silver.
.

That's actually quite smart 😀

Did you find a solution yet? I'm also having trouble getting a 486-100 with a Phoenix BIOS to post on my DEC 466. I've tried two so far but no luck even after trying the suggestions in this thread.

If you find a solution post it up. I realize it's two different MB's/CPU's and BIOS's but who knows it might help.
Thanks

No, sorry, didn't have the time to test it, will do tomorrow. I seem to recall having tried other RAM configurations as well, though.