Sun 3/80 magic smoke

[Curtis H. Wilbar Jr.]

Tried to power up a Sun 3/80 mainboard...

Inductor L0500 (right near the power input) (I assume this is an
inductor by the L0500
marking on the PCB) smoked....  (pink smoke no less)

Anyone familiar with the 3/80 to give an idea of why this might have smoked.

Board appears in excellent condition, no foreign objects on the board,
no sign of any
shorts that I can see.

Would like to rescue this board.  If it was a PC I'd look for bulging
electrolytics...

Anyone got a schematic for the 3/80 ?  (I've never seen any Sun schematics).

-- Curt
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[Jonathan Katz-2]

On Sat, May 10, 2008 at 8:56 PM, Curtis H. Wilbar Jr.
<rescue@...> wrote:
> Tried to power up a Sun 3/80 mainboard...

This is the best I can come up with...

http://sunsolve.sun.com/handbook_pub/validateUser.do?target=Systems/Sun3/CPU_11_Sun-3-80

http://sunsolve.sun.com/handbook_pub/validateUser.do?target=Systems/Sun3/SYSTEMS_07_Sun-3-80

http://sunsolve.sun.com/handbook_pub/validateUser.do?target=Systems/Sun3/TrCPU_TOC
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[Jeff Cole]

Curtis H. Wilbar Jr. wrote:

> Anyone got a schematic for the 3/80 ?  (I've never seen any Sun
> schematics).

The FE Handbook for Sun 3 stuff probably has what you're looking for. .

http://sunsolve.sun.com/handbook_private/validateUser.do?target=Systems/Sun3/FEH3.enter

You'll need a support contract obviously, or a friend willing to loan
you one.
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[r.stricklin]

On May 10, 2008, at 5:56 PM, Curtis H. Wilbar Jr. wrote:

> Anyone familiar with the 3/80 to give an idea of why this might have  
> smoked.

You have a short across the -12V rail. I have two 3/80 boards with the  
same symptom. I haven't had time yet to track down where the short is  
(most likely to be a cap).

ok
bear
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[Curtis H. Wilbar Jr.]

r.stricklin wrote:
> On May 10, 2008, at 5:56 PM, Curtis H. Wilbar Jr. wrote:
>
>> Anyone familiar with the 3/80 to give an idea of why this might have
>> smoked.
>
> You have a short across the -12V rail. I have two 3/80 boards with the
> same symptom. I haven't had time yet to track down where the short is
> (most likely to be a cap).

One of those yellow surface mount ones ?

Are those tantalum or just surface mount electrolytics ?

If one is a dead short, guess it should be easy to spot with a dvm, I'll
have
to check all the identifiable caps around the power connector area.

-- Curt

>
> ok
> bear
> _______________________________________________
> rescue list - http://www.sunhelp.org/mailman/listinfo/rescue
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