Indigo 2 Xz with no LED light.

[workyboy]

Newbie here. Just picked up what looks like a near new Indigo 2 Xz and the indicator LED on the front panel won't light up. Followed the instructions in the user manual and firmly pressed down the "gold wall" (EISA backplane ) that holds the accessory cards.
2. Remove the top cover from the system and make sure the EISA backplane is firmly seated by pressing down on top of it. The backplane is the gold-colored metal wall that extends from the fan in the front of the system, along the back of the expansion board slots, to the back of the chassis. It’s okay to press quite firmly on the top of the backplane wall.
3. Check to make sure the internal power connectors are attached correctly to the system board. They are tight.
Both fans start up, floppy and hard drive LED's light up, dead monitor, what to do now?
Thanks in advance for any help you can provide.

 

[flexion]

Hi and welcome! Nice find!

Attach a serial console? Re-seat the graphics sandwich?

 

[workyboy]

Thank you for the leads.
Attach a serial console? What is the serial console? My ignorance is showing.
Re-seat the graphics sandwich? Are you saying remove all the cards and reseat them?
Could it be that the OS is not installed? I do have the OS disk?
Thanks again,

 

[flexion]

If there is no OS installed, you would still get at least something on the screen telling you what's wrong.

By re-seating the gfx "sandwich" I meant remove the graphics card combo and insert again, just as you did with all other connectors.
Serial RS232 console would maybe show some more information about what's going on (or not) when the system powers up but can't display anything on the screen for whatever reason. but could also be that there is no output on the serial console at all, since you say the LED does not light up.

Attach a terminal to the serial port with null-modem cable and 8N1 at 9600 (although not 100% sure about baud rate).

 

[workyboy]

flexion,
I really appreciate your help. I just pulled and reset all the connectors and graphic card combo. Still no life. I was so hoping that it would fire up after reinserting everything. It sounds like it might be beyond my skills and equipment to find out what's wrong. It could be time for the pros.
Thanks,

 

[weblacky]

Normally these days..99.99% it’s the power supply malfunctioning due to age. There is a small chance it’s not. But we always tell people to check that first. Older SGI’s heavily use 3.3 V and 5 V lines. The lack of mainboard start up probably means that your 3.3 V powerline can no longer provide enough amps.

However lucky for you a teal Indigo2 uses is a much simpler power supply and is therefore a lot cheaper on the used market. I haven’t seen any lately but about 2 to 3 years ago you could pick them up on eBay for around $40-$50. The purple Indigo2s however are a different power supply in a totally different price range.

Technically you can put a newer, more expensive, Indigo2 power supply in an older Indigo2 and run it. So you finding a power supply is much easier than later stations.

 

[Elf]

If the PSU is suspect, might as well measure it though

 

[weblacky]

If the PSU is suspect, might as well measure it though

Can you recommend a simple way? I suspect it will measure "fine" . Even though the symptom is 12V running, The PSU isn't shutting off. So either the PSU isn't detecting the error...or there is no error as far as it's concerned? I'd image a shorted cap or something would still make the PSU halt at max load and burn out the shorted component? Would a mainboard zombie if there was too much ripple/AC on output? That at least could be measured with a multimeter via AC setting on DC outputs, I guess.

 

[Elf]

If it isn't capable of supplying enough load I would expect the lines to be sagged (e.g. below 3.3/5/12), or for overcurrent protection just to shut the supply down. Certainly excessive ripple can disrupt things, which can be measured as you suggest. Past that, one could put it on a scope with a long time division to see how the rails start up (if they take too long, sag, or start up irregularly in some way), and which could give a better view on ripple as well.