Hello,

I'm having problems trying to put in service again a refurbished
Enterprise 450. The computer has 2 power supplies installed and
currently no hard disks, keyboard/mouse nor monitor.

When I turn it on (with the front key in "stand by" position and both
side panels installed) nothing seems to happen: the front leds don't
light and fans don't start. On both power supplies, the rear leds "load
status" and "AC-present status" turn on, but not the "DC status" led.

I found an old post on the Sun website from a guy experimenting the same
after installing an UPS, but that is not my situation.

Thanks in advance for any help!

Marco.

"Muttley" <fake.address@fake.provider.it> wrote in message
news:44a7a10f$0$989$5fc30a8@news.tiscali.it...
> Hello,
>
> I'm having problems trying to put in service again a refurbished
> Enterprise 450. The computer has 2 power supplies installed and
> currently no hard disks, keyboard/mouse nor monitor.
>
> When I turn it on (with the front key in "stand by" position and both
> side panels installed) nothing seems to happen: the front leds don't
> light and fans don't start. On both power supplies, the rear leds "load
> status" and "AC-present status" turn on, but not the "DC status" led.
>
> I found an old post on the Sun website from a guy experimenting the same
> after installing an UPS, but that is not my situation.
>
> Thanks in advance for any help!
>
> Marco.

I had a E450 with 3 power supplies that did the same thing.
Asked one of the Unix Admins at work about it. He said that
the symptom indicated a DC power problem, by which I think he meant
the DC-DC converters (aka VRMs) were bad. Luckily mine had 1GB of
good memory in it, which I am now using in an Ultra60. Pulled out
everything else of value and trashed the case. There was no way I was
actually going to crank up those 3 x 700W PSUs at home anyway.

Sun makes a very nice T2000 now that uses just 400W or so?

>>I'm having problems trying to put in service again a refurbished
>>Enterprise 450
[snip]
>>On both power supplies, the rear leds "load
>>status" and "AC-present status" turn on, but not the "DC status" led.
[snip]
> I had a E450 with 3 power supplies that did the same thing.
> Asked one of the Unix Admins at work about it. He said that
> the symptom indicated a DC power problem, by which I think he meant
> the DC-DC converters (aka VRMs) were bad.

If it was the VRM (my E450 has one processor+VRM installed) maybe I
could find a spare one for testing. Actually, I've read there's a hole
circuit board for distributing DC currents inside the computer and I
suspect that's the faulty part... which of course would be much harder
to replace. By the way, I think the PSUs are ok, since a fault in both
of them seems unlikely to me.

> Luckily mine had 1GB of
> good memory in it, which I am now using in an Ultra60. Pulled out
> everything else of value and trashed the case.

That, of course, will be my last resort...

Thanks!

Marco.

"Muttley" <fake.address@fake.provider.it> wrote in message
news:44a98e51$0$993$5fc30a8@news.tiscali.it...
> >>I'm having problems trying to put in service again a refurbished
> >>Enterprise 450
> [snip]
> >>On both power supplies, the rear leds "load
> >>status" and "AC-present status" turn on, but not the "DC status" led.
> [snip]
> > I had a E450 with 3 power supplies that did the same thing.
> > Asked one of the Unix Admins at work about it. He said that
> > the symptom indicated a DC power problem, by which I think he meant
> > the DC-DC converters (aka VRMs) were bad.
>
> If it was the VRM (my E450 has one processor+VRM installed) maybe I
> could find a spare one for testing. Actually, I've read there's a hole
> circuit board for distributing DC currents inside the computer and I
> suspect that's the faulty part... which of course would be much harder
> to replace. By the way, I think the PSUs are ok, since a fault in both
> of them seems unlikely to me.
>
> > Luckily mine had 1GB of
> > good memory in it, which I am now using in an Ultra60. Pulled out
> > everything else of value and trashed the case.
>
> That, of course, will be my last resort...
>
> Thanks!
>
> Marco.

That DC distribution circuit board is certainly possible as a culprit. Good
luck.
Yes your PSUs are probably ok. I also could not image that all 3 of mine
went bad at the
same time, very unlikely.