[rescue] Sun4 FPU errors

[Steve Rikli]

While I wouldn't rule out a faulty CPU module (which essentially implies
the whole system board in a Classic or LX iirc), I would probably start
troubleshooting with memory.

If nothing else, it tends to be easier to shuffle and swap memory modules
than a soldered CPU.

I had a couple Classic and an LX before donating them (likely to some
good folks on this list :-) ) and I seem to recall faulty SIMMs (or slot)
sometimes looking like CPU errors.

So e.g. I would start with populating only the minimum -- a matching pair
of SIMMs (or DSIMMs, I suppose) in Bank 1, which should be slot U0303 and
U0304 according to the Classic/LX Service Manual (801-2176-13).

See if your diag errors reproduce, try a different pair of memory, etc.

Cheers,
sr.


On Mon, Jan 02, 2023 at 03:58:11PM -0500, Mark Price via rescue wrote:
> Hello list,  happy new year!
> 
> I'm brushing off a SPARC classic I recently received from a fellow
> list member.
> 
> Currently I'm stuck with FPU errors when powering on.  I haven't yet
> found any useful troubleshooting info online, so I thought I would see
> if anyone here has insight or suggestions.
> 
> Is this simply a bad CPU?
> 
> 
> The system bounces between a few different errors when powering on,
> examples are:
> 
> -------------------------------------------------
> MMU Context Table Reg Test
> MMU Context Register Test
> MMU TLB Replace Reg Test
> MMU Sync Fault Stat Reg Test
> MMU Sync Fault Addr Reg Test
> MMU TLB/CAM NTA Pattern Test
> D-Cache RAM NTA Test
> D-Cache TAG NTA Test
> I-Cache RAM NTA Test
> I-Cache TAG NTA Test
> FPU Register File Test
> FPU Misaligned Reg Pair Test
> FPU Single-precision Tests
> FPU Double-precision Tests
>      ERROR : FPU Double-precision Operation, exp = 40390000 00000380, obs = 4039
> 0000 000003c0
>      U-NUMBER : Suspect Tsunami Module
> 
> -------------------------------------------------
> 
> MMU TLB/CAM NTA Pattern Test
> D-Cache RAM NTA Test
> D-Cache TAG NTA Test
> I-Cache RAM NTA Test
> I-Cache TAG NTA Test
> FPU Register File Test
>      ERROR : FPU Registerfile Stuck-at Fault
>          00000000 :  00000000  00000380
>          00000002 :  00000000  00000380
>          00000004 :  00000000  00000380
>          00000006 :  00000000  00000380
>          00000008 :  00000000  00000380
>          0000000a :  00000000  00000380
>          0000000c :  00000000  00000380
>          0000000e :  00000000  00000380
>          00000010 :  00000000  00000380
>          00000012 :  00000000  00000380
>          00000014 :  00000000  00000380
>          00000016 :  00000000  00000380
>          00000018 :  00000000  00000380
>          0000001a :  00000000  00000380
>          0000001c :  00000000  00000380
>          0000001e :  00000000  00000380
>      U-NUMBER : Suspect Tsunami Module
> -------------------------------------------------
> 
> 
> 
> Best Regards,
> 
> Mark
> 
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