Sun SPARCstation LX

The Sun SPARCstation LX (aka sun4/30) is a "lunchbox" style Sun workstation based around the sun4m architecture.

Machine won't boot and/or throws various firmware errors
Examples: Sun Workstation, Model Sun-XXXXXX Series. ROM Rev X.X, XXMB memory installed ID PROM invalid. Testing 0 Megabytes of Memory ... Completed. ERROR: missing or invalid ID prom Requesting Internet address for 0:0:0:0:0:0 or Sun Workstation, Model Sun-XXXX Series. Type 4 Keyboard ROM Rev X.X, XXMB memory installed, Serial #16777215 Ethernet address ff:ff:ff:ff:ff:ff, Host ID ffffffff Invalid format type in NVRAM The IDPROM contents are invalid

Causes

 * NVRAM chip battery has failed

Solutions

 * Replace the NVRAM chip (See below)

Disassembly Notes
Warnings or tips to disassemble then device

Power Supply
The power supplies in the "pizza box" and "lunch box" style Sun workstations are notorious for having leaky electrolytic capacitors.

NVRAM Chip
The SPARCstation LX has an NVRAM chip that functions as both NVRAM (system configuration storage) as well as the real time clock. It is a one-chip device that has both the NVRAM as well as a clock battery integrated in the same chip, similar to the Dallas RTC chips used in many x86 PCs. The chip is located at U0707, and is a SGS-Thomson (formerly Mostek) Timekeeper M48T08/18. It may also be referred to as the Mostek MK48T08/18.

These chips are still available, however newer versions of this chip (those currently available) will not work. Newer variants of this chip now include a "century" field which the older Sun firmware does not understand. (it will work, but the system will always boot into the lengthy extended diagnostics mode and will not auto-boot.) You must obtain a used or NOS (new old stock) version of this chip.

Alternatively, a user-replaceable CR1225 coin cell battery can be retrofitted onto an existing NVRAM chip, by cutting off the top of the chip (the portion that contains the battery) and soldering on a PCB containing a new battery. GlitchWorks has designed such a PCB and has released it as Open Source Hardware. Directions can be found on their website, and the PCB design files can be found on the Glitchworks Github repository.

Basic PCB Name
If parts are not available or different selection is preferred, you can use the values in the Original Parts section to perform a parametric search.

Kits

 * Digikey BOM: https://www.digikey.com/

Related Links

 * Service Manual
 * Sun NVRAM/hostid FAQ - contains additional information about failed NVRAM and how to reconfigure the machine after a NVRAM failure