SGI Indigo R4000, R4K PSU vs R3K PSU?

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telmnstr
Posts: 6
Joined: Wed Apr 21, 2010 1:15 pm

SGI Indigo R4000, R4K PSU vs R3K PSU?

Unread postby telmnstr » Fri Dec 09, 2016 8:00 pm

Hello everyone!

Old time SGI ex-fanboy here. I finally collected up all the parts for my first SGI, a R3000 Indigo I bought from Reputable Systems back in the day.

I thought it was a R3K/Entry graphics (or at least 8 bit color only graphics) but it turns out I swapped the CPU board with a R4K and the graphics is Elan. I used to have a lot of deskside systems and I think the Elan came from a frame that adapted it to run in a Crimson or something, and the CPU board came from a different Indigo that worked but then the PSU died.

Upon powering on my Indigo I got a burning smell. I did get framebuffer output, LED was green then orange. Saw the clock warning will fix that later. But I didn't realize I had both R4K + Elan, and IIRC you can only have one or the other on the R3K PSU?

First off, odds of finding a R4K Indigo PSU for sale?

Second, what happens when you overload the R3K PSU? Is the burning smell I got a result of that? Or could something else be failing (cap/resistor?)

I sniffed all over the PCBs and it smells like it's in multiple places but looking at the boards there is nothing that looks burned, or stressed.

Any thoughts or anyone have experience with this series?

telmnstr
Posts: 6
Joined: Wed Apr 21, 2010 1:15 pm

Re: SGI Indigo R4000, R4K PSU vs R3K PSU?

Unread postby telmnstr » Fri Dec 09, 2016 8:17 pm

Well crap, pulled the PSU and it's a R4K model PSU. Also, nothing inside smells very bad.

telmnstr
Posts: 6
Joined: Wed Apr 21, 2010 1:15 pm

Re: SGI Indigo R4000, R4K PSU vs R3K PSU?

Unread postby telmnstr » Fri Dec 09, 2016 9:23 pm

And it looks like there is a rectangle SMD yellow capacitor on the bottom of the CPU board that went toasty. C551. Wonder if it's worth replacing all of this style capacitor on the main board.

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pentium
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Re: SGI Indigo R4000, R4K PSU vs R3K PSU?

Unread postby pentium » Sat Dec 10, 2016 10:07 am

That sounds like a tantalum. They do that at random as they get old and they're really hard to determine if they're about to fail. I just replace them as they short and fail.
:Crimson: :Onyx: :O2000: :O200: :O200: :PI: :PI: :Indigo: :Indigo: :Indigo: :Octane: :O2: :1600SW: :Indigo2: :Indigo2: :Indigo2IMP: :Indigo2IMP: :Indy: :Indy: :Indy: :Cube:

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telmnstr
Posts: 6
Joined: Wed Apr 21, 2010 1:15 pm

Re: SGI Indigo R4000, R4K PSU vs R3K PSU?

Unread postby telmnstr » Mon Dec 12, 2016 6:15 pm

Sweet! I have a Digikey order going in soon. Took notes, blogged it at ethan.757.org

SGI Indigo SMD tantalum caps of the style of the one that burned up:

Top of PCB:
C14, C15, C23, C48 = 47uF,16v
C30 = 33uF, 20v

Bottom of PCB:
C555, C544, C525, C513A, C513B, C578A, C578B, C645A, C645B = 47uF, 16V
C697 = 33uF, 16v
C551 = 33uF, 20V
C507? = 10uF, 10V

C551 is the crispy one

47uF/16v = 7.3mm x 4.42mm : Size 2917 (7343 Metric) / Digikey – 478-1739-1-ND
33uF/20v = 7.44mm x 4.33mm : Size 2917 (7343 Metric) / Digikey – 399-3788-1-ND
10uF/10v = 5.5mm x 3.3mm :
33uF/16v = 7mm x 4.45mm :

robespierre
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Location: Boston

Re: SGI Indigo R4000, R4K PSU vs R3K PSU?

Unread postby robespierre » Tue Dec 13, 2016 12:17 pm

There is no reason to use the Tl-MnO2 type of capacitors anymore, unless cost is paramount. They have been superseded by polymer-cathode types that do not burn up when they fail. A nice bonus is that deep derating is not required, and they have much better (lower) ESR.

For the 33uF 20V tantalum MnO2, you can substitute a 33uF 16V polymer.
http://www.mouser.com/ProductDetail/Kem ... 016ATE040/
:PI: :O2: :Indigo2IMP: :Indigo2IMP:


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