The IDPROM contents are invalid. Power on Self Test Failed Cause: NVRAM U13On the motherboard in a strange socket with two "handles" is a "Timekeeper RAM" chip. The part number for the Ultra 5/10 is an ST microsystems M48T59Y-70PC1, which is a 64 kbit chip (8K by 8 bit). These things are an 8K x 8 static ram chip with a lithium battery piggybacked on top and encased in plastic and epoxy. As you might expect, after 20 years these batteries have in most cases gone dead.
Fix things by hand so you can bootThis is not all that bad and only takes about 2 minutes of careful typing. Of course this will be unacceptable if these machines need to remotely administered. On the other hand, anyone using these old fossils for anything critical is a fool anyway, so any amount of coddling is reasonable and acceptable.
You need to get to the boot monitor "OK" prompt. You are probably there already if you have this problem, but if not, type L1-A to get there. Then type the following. See the notes below on the values for xx, yy, and zz.set-defaults 1 0 mkp 80 1 mkp 8 2 mkp 0 3 mkp 20 4 mkp xx 5 mkp yy 6 mkp zz 7 mkp 0 8 mkp 0 9 mkp 0 a mkp 0 b mkp xx c mkp yy d mkp zz e mkp 0 f 0 do i idprom@ xor loop f mkpType "banner" and check the ethernet address and host ID.
Then type "reset" to boot the machine.
The values xx:yy:zz are the last 3 bytes of the MAC address for the machine. If you examine the NVRAM chip in the machine, it should have a yellow sticker with a barcode and 6 hex digits. In my case these are 9F:BC:C0, and these are the last 3 bytes Sun assigned to the MAC address for this particular machine. Note that the first 3 bytes of the MAC address are always 8:0:20 for Sun. You will notice those bytes in the sequence above.
The following is quite dated, but has valuable information nonetheless.
su date 1004043018The format is mmddHHMMYY, so the above is 04:30 on 10/4/2018
The following is the datasheet for a very similar part.