[weblacky]

Considering the PSU is over 20 years old (and I don't think any conformal coating was used on I2 PSUs to seal them) and contains components from that period, yeah the components you should worry about aren't the semiconductors (digital), its the passives (the caps, inductors, an resistors) and metal legs, and realize many of these systems were stored in people's garages and other places where they had low temps and high humidity occur (versus inside a temperature controlled house). Wire wound and metal film resistors are affected by these poor storage environments and change resistance over time. Typical startup circuits use high Ohms values, when these drift, they quickly drift outside the 10% tolerance or whatever of the resistor.

A small example of how critical resistor values are in startup function of PSUs: https://www.industrial-electronics.com/s...y_1-8.html

Let us know if you manage to isolate it.

[sunray]

Once In have located the fault I for sure will post it here.

Should add that I don't agree that resistors are prone to fail, caps are yes due to heat mostly so it is important to not only
pict the correct F but also the needed Celsius value usually 105 degress in a PSU.

[sunray]

Some updates and I have come a little further in getting the Indigo2 running as it should.

First, I removed the NVRAM then the machine comes up with a warning about clock not set, the system time is then 1970 UNIX Epoc.

Setting up ntp on IRIX to point to my Solaris 11 fileserver and reboot will then make IRIX come up with correct time, so thats great.

The after ordered some NVRAM from China and installed them,  the machine comes up and keeps the time even when network is not connect so now atleast the clock in the NVRAM is working as it seams but I still have the always on not possible to poweroff issue, BUT now when executing # init 0 (poweroff) IRIX actually plays the song whe shutting down, this was not the case without NVRAM.

But I have not found a jumper that could explain the "always on" issue.

Oh also received a brand new INDYCAM from Ebay(my old did not work), so now I have video in

And a unopened brand new 100Mb/s G160 network board


To be cont.