SGI Fuel, L1 console, getting DS1870 ALERT and no prompt

[cz7asm]

Hi,

I'm trying to fix my first Fuel and I'm having a problem of not getting an L1 prompt. The only thing I got after connecting the power is this:

ALERT: Error initializing DS1780 1, no acknowledge
ALERT: Error initializing DS1780 2, no acknowledge

I'm sure a few weeks ago when I tried to power it up for the first time I got these alerts and prompt as well but this time it's just these alerts. Any idea why?
Also could someone point me to where are those DS1780 located? I ordered new ones and want to try to resolder them.

Many thank for any help!

 

[cz7asm]

I managed to replace the faulty DS1780 and now I'm getting no ALERTs but still no prompt. Basically the console output is silent but I know it's not a dead board because if I unplug the processor board it gives me another alerts. Is there any precondition that I'm missing to get further in the L1 process and get the prompt? I took the motherboard from the case but I doubt there is any mechanism that detects this...must try.

Any help or hints are much appreciated.

 

[weblacky]

I assume you know about the whole Ctrl+t and Ctrl+d thing? And the fact the Fuel doesn't route the terminal through the L1 console port: https://gainos.org/~elf/sgi/nekonomicon/forum/3/16730517/1.html

The L1 console doesn't just "come up", sure log output does, but not the command prompt for serial L1. You have to call for it. You switch console modes with ctrl+t and ctrl+d.

I've been told if the machine isn't actually running (so active L1 without Power-on). You should be saying "ctrl+d", and see the L1 react, then press "ctrl+t" for L1 terminal.

I *think* you should be seeing the L1 terminal through the internal Mainboard Serial port, but I'm unsure as the Fuel is one of two systems I still don't own yet. But that's what the various info says about your symptoms.

 

[cz7asm]

Thank you weblacky, the issue was actually much simpler but not easy to find. It was an incorrect type of null modem cable where only RX and TX lines are crossed but the remaining signals are straight. Since L1 firmware appears to care about flow control with exception of ALERT messages, it explains the behaviour I was getting. I tinkered with the cable, crossed the RTS and CTS lines and finally I have the prompt!