On Mon, 10 Feb 2003 pete(a)dunnington.u-net.com wrote: Peeling back the DEC part# labels, it's clear that they're vanilla, UV eraseable, EPROMs. They're both TI 27C210A-12; I guess I don't need to be concerned about having modified them. So, assuming the console ROMs are fine, that means something critical has died in my VAXstation 4000 VLC between the short period of time between powering it down and powering it up again. The diagnostic LEDs on the back of system indicate the following pattern (where the lower part represents lit LEDs as 1 and unlit LEDs as 0): 7654 3210 --------- 1111 1101 At initial power on, all the LEDs are lit "1111 1111", a fraction of a second later it changes to the "1111 1101" pattern and stays there. Using the following page, I get some hints about what may be going wrong <http://home.iae.nl/users/pb0aia/vax/3100leds.html>, but nothing entirely conclusive as I'm not sure whether the codes for the VS3100 map usefully to those for the VS4000. Some other suggestions that had been made were to check the SIMMs, check the power supply, and to check the RTC chip. Fortunately, I can swap bits between this dead system and another good one that I have. The power supply works, the SIMMs work, and the RTC chip works. I'm getting down to the point of it either being some faulty component or connection on the mainboard, or possibly it /is/ still something with the console EPROMs, though not for the reason I suspected earlier. I should be able to swap the EPROMs a little later on today, and then there's a daughter card which contains a frame buffer, various other I/O ports, and the halt button. Following that, it's down to checking individual (mostly surface mounted) components on the main board. On the bright side, I've a working system which can be used as a reference. Also, the mainboard on the VS4000/VLC is fairly simple-- at least in that it has few components, though they might not be so easy to replace. -brian.