The collected works of dir_marillion - Page 2

Hi SAQ,

If I replace my dead NVRAM chip with the chip M48t08 (I checked and my NVRAM has 24 pins, I assume 150 is the speed of the chip...) and follow the procedure to import the (hopefully correct) mac address I kept, its possible that the system will have all the necessary information to enable the on-board NIC into Solaris.

Otherwise may I install another S-BUS network card (which has it's own mac address) and use it as primary Ethernet controller ?

Thank you very much guys, I have already ordered a M48t08 and I will replace the dead NVRAM with it.
This SS20 will be used at my home, among SGIs, so no need for VLANs or more complicated networks.

Then I will re-program the MAC and the serial via openboot.

Hey guys, for your info, I received the (new) M48t08 and replaced the official NVRAM. I have already reprogrammed it with success.
M48t08 works fine with Sparcstation 20.

Let's see in how many years, the battery will come to it's end.

Thank you very much SAQ.

Hi,
I know it is an old thread but after a full capacitor-replacement of the SS-20 Power Supply, the computer does not turn on anymore (not even the fans). Actually it is completely dead. We have used the same values of capacitors (some capacitors with higher voltage value).

A second SS-20 we have here is working (with it's old capacitors), so we have double-checked that the lines are not corrupted and fuse is also ok. Before the capacitors replacement, SS-20 was turning on but we had to do this because of capacitors leakage. Power switch seems good, the computer also does not turn on via keyboard.

Do you have an idea what may cause this problem ?


Thank you

We have used high quality capacitors of same capacity and voltage rating (some capacitors have higher voltage value). The work of recapping has been done professionally and lines have been checked for errors, wrong joints or short circuits, according to the other power supply which is working. As the power supply is completely dead, I suspect another component that died during the first turn-on (probably due to the current correct voltage of the new capacitors).

I searched for a generic power supply troubleshooting guide and I found this: http://www.giangrandi.ch/electronics/sm ... sfix.shtml which in my case "No output, good fuse" it mainly suspects regulators, zener diodes, resistors etc.

Does SS-20 power supply have similar architecture and operation with the power supply described in the above link ?
If yes, do you suspect which component could be failed ?

No problem. We have already tested all capacitors and they are operating perfectly. The issue has to do with another component. If we fix it in the future, I will let you know.