Onyx System Controller Repair - Printable Version

+- IRIX Network Forums (//forums.irixnet.org)
+-- Forum: SGI/MIPS (//forums.irixnet.org/forum-3.html)
+--- Forum: Hardware/Triage/Repair (//forums.irixnet.org/forum-11.html)
+--- Thread: Onyx System Controller Repair (/thread-1498.html)

---

Onyx System Controller Repair - ColanderCombo - 09-16-2019

I'm trying to bring up a deskside Onyx, and it looks like the system controller is damaged. When powering the system on, everything looks good until I get a "BLOWER FAIL" message and everything shuts down. The blower *is* running, but the controller reports 0 RPM. I've tried reseating all the cables, but everything looks good. Taking a cue from an archived nekochan thread:

http://archive.irix.cc/apocrypha/nekonomicon/forum/3/16723683/1.html

I pulled the system controller, and it looks like several SMD transistors are damaged or missing.

Much like the poster of that 10-year-old thread, could I request that someone take a high-resolution photo of the back of their operable system controller so I can identify the missing components?

For reference it looks to me like the following labeled components are missing/damaged:

M7C5B
M4C5B (resistor?)
L8C4B (2A?)
M0B9B
M9B1B (SD?)
M7B1B (SD?)
L5B7B

---

RE: Onyx System Controller Repair - jan-jaap - 09-16-2019

(09-16-2019, 07:32 AM)ColanderCombo Wrote:  Much like the poster of that 10-year-old thread, could I request that someone take a high-resolution photo of the back of their operable system controller so I can identify the missing components?

I'll have a look, I think I have a spare system controller. PM me if I don't report back in a couple of days

---

RE: Onyx System Controller Repair - ColanderCombo - 09-16-2019

(09-16-2019, 08:07 AM)jan-jaap Wrote:  

(09-16-2019, 07:32 AM)ColanderCombo Wrote:  Much like the poster of that 10-year-old thread, could I request that someone take a high-resolution photo of the back of their operable system controller so I can identify the missing components?

I'll have a look, I think I have a spare system controller. PM me if I don't report back in a couple of days

Thanks!

---

RE: Onyx System Controller Repair - mosiniak - 09-22-2019

(09-16-2019, 08:33 AM)ColanderCombo Wrote:  

(09-16-2019, 08:07 AM)jan-jaap Wrote:  

(09-16-2019, 07:32 AM)ColanderCombo Wrote:  Much like the poster of that 10-year-old thread, could I request that someone take a high-resolution photo of the back of their operable system controller so I can identify the missing components?

I'll have a look, I think I have a spare system controller. PM me if I don't report back in a couple of days

Thanks!

If You need I can provide hi-res photos of system controller. Do You have any preferences?

---

RE: Onyx System Controller Repair - ColanderCombo - 09-22-2019

(09-22-2019, 09:40 AM)mosiniak Wrote:  If You need I can provide hi-res photos of system controller. Do You have any preferences?

I would appreciate it.

Here's an annotated version of my earlier image with the components I'm interested in circled. I'm trying to determine the markings on the missing/damaged components.

---

RE: Onyx System Controller Repair - jan-jaap - 09-23-2019

OK, here's an attempt. Some of these small SMD caps don't have any or only very faint markings. My guys in the lab tell me this is not uncommon. Maybe you can recover something if you play with contrast in Photoshop; I did my best to play with the light to get the best.

I annotated your photo some more to tell you what's what, because these photos are taken with a microscope. The actual photos are served up from my server

#01


#02


#03


#04


#05


#06


#07

---

RE: Onyx System Controller Repair - jan-jaap - 09-23-2019

I think the SMD capacitor in #2 reads "A5", if the orientation on #4 is the same, it might read "08" but that one is very very hard to decipher.

---

RE: Onyx System Controller Repair - ColanderCombo - 09-23-2019

This is great; precisely the info I need! I've been able to identify the transistor-like SOT23 parts. The 5D is actually a diode, 1AMC and 2AK are transistors.

I agree with your reading of the capacitors. A5 matches with a code for 0.1uF here:

https://electronics.stackexchange.com/questions/115095/surface-mount-capacitor-marking

There doesn't seem to be a O8... but it could be B0. For the time being I'm gonna guess that's what it is.

I've placed an order at newark and should have my replacement parts by the end of the week. I'll post an update once I know more. Thanks again!

---

RE: Onyx System Controller Repair - ColanderCombo - 10-02-2019

Success!
Huzzah!

Using the markings provided above, I replaced the missing and damaged components on the back of the system controller board and the blower speed is now correctly sensed and I've been able to boot the system.

I had some odd issues with the RE2 pipe, but after some reseating and board swapping I have a mostly working system.

I have had two seemingly random 'POKB FAIL's w/instant poweroff; one after clicking the 'reboot system' option in the system management window, and the other while running the atlantis demo. I don't think I have enough data to guess whether this is indicative of some other component failing or that there's still a problem with the system controller. If I keep experiencing POKB's I'll double-check the controller.

Now to debug the somewhat flakey RE2!

---

RE: Onyx System Controller Repair - jan-jaap - 10-02-2019

Awesome!

Refer to section about the power system in the Challenge/Onyx Diagnostic Roadmap.

Several problems can result in POKB errors:


You'll have to find the red fault LED when a POKB happens. They're quite hard to spot on the VCAM when the IO4 is installed in the system.

---