Semi-newbie trying to repair SGI Indy PS
David S. Pieczkiewicz
I have a Silicon Graphics Indy with a Nidec power supply, which
appears to be faulty (machine won't boot). Various vendors have offered
me outright replacements, but I am on a limited budget, and would first
like to try my hand at repairing the dead supply myself, if possible.
I'm asking if any readers have experience with repairing this power
supply, or similar models. Judging from what I've read and heard, Indy
power supply failures are rather frequent, so I'm imagining there might
be some common underlying causes.
The particulars of the power supply: Nidec/Power General
FLU5-170-1-6560, with the following rated outputs:
+5 VDC at 25A
+3.3 VDC at 7A
5V AUX at 1 mA
+12 VDC at 4.5A
-12 VDC at 0.75A
There are no obviously faulty/burned/etc. components. I've made a
few measurements, and it seems as though only one of the pinouts is
giving any voltage (+5). However, I do not specifically know the
pinouts for the supply itself, and am also wondering if this is one of
those power supplies that has to have loads or other types of
bootstrapping, in order to turn on completely. I've checked the main
power switch/button in the front, and it appears to work, and gets +5V.
Pushing it, though, has no effect. The fan in the rear of the supply
does not turn on, either.
I'm not entirely new to electronics, but I admit that this is the
first time I've gotten into the guts of a power supply. (Before anyone
panics, I have gotten familiar with the requisite precautions for
handling this type of equipment.) As such, I'm looking on this as a
learning exercise, as well as a repair. I would be most appreciative
for more experienced readers' tips and constructive guidance.
To sum up my questions: for this power supply, are there any
components which are more likely to have failed? If so, what is the
best way to test them (i.e., in or out of circuit)? Since there is
*some* power coming out of the supply, I'm guessing that the problem
doesn't lie in "basic" parts, like the filter capacitors or main
transformers, but possibly in the low-voltage part of the supply. Just
my semi-educated guess, though... :)
Again, I would be appreciative of any comments or feedback. If I've
left important details out (which is entirely possible), let me know,
either by post or email.
Thanks,
Dave...
=====
David S. Pieczkiewicz, M.A.
Division of Health Computer Sciences
University of Minnesota, Twin Cities Campus (612) 625-3241
http://www.labmed.umn.edu/~david/ da...@email.labmed.umn.edu
mrob...@worldnet.spam-not.att.net
: I have a Silicon Graphics Indy with a Nidec power supply, which
: appears to be faulty (machine won't boot). [...]
: There are no obviously faulty/burned/etc. components. I've made a
: few measurements, and it seems as though only one of the pinouts is
: giving any voltage (+5). However, I do not specifically know the
: pinouts for the supply itself, and am also wondering if this is one of
: those power supplies that has to have loads or other types of
: bootstrapping, in order to turn on completely.
I'm not an expert, but _all_ the various switching supplies I've fooled
with needed a load on their main output to turn on. From the specs
you gave it's pretty obvious that the +5v/25A is the main output. :)
Try a couple of car tail-light bulbs or a headlight bulb on this output
and see if the supply wants to come up any better then.
As far as finding any "sense" or "bootstrap" wires...often you can
do this simply by the wire colors. For example, if you can find out,
by case label, circuit board silkscreen, or tracing the circuit,
that all the red wires are +5v, all the yellow ones are +12v, etc,
then concentrate on the ones you can't figure out. PC supplies,
for example, have a "power good" line coming out. The supply still
works if you don't connect it, but some motherboards want to see
it in order to come out of reset. I have seen some other supplies
advertised in surplus that have a couple of wires that must be
connected to work...either a "remote switch" or a "sense" wire
that must be tied to one of the voltage outputs. Anyway, there
will probably be only one or two "switch" or "sense" wires, and
they will probably be uniquely colored wrt the rest of the
"main power" wires.
It looks like the +5V Aux output should run all the time, probably
to allow for booting by pressing a "little" button (like a keyboard
key) and not a "big" one (main line power switch). That would
almost imply some kind of sense input to the supply:
1. Main outputs of supply are off, +5V Aux is on, powering circuit
for "boot" button.
2. User pushes "boot" button. This causes a contact closure
across a couple of sense lines into the supply, or switches one
sense line to ground or to the +5V Aux line.
3. Main outputs of supply come up and machine boots.
I have a feeling that the +5v you can measure is the Aux line,
and that you're not doing something with one of the sense wires
to make it happy. In other words, for bench testing, you will
need some input to the sense wires to give it *permission* to
start the main outputs, and a load on the +5V/25A output so it
is *able* to start the main outputs. Does this make sense?
You may have already looked at the FAQ, but if not:
http://plop.phys.cwru.edu/repairfaq/REPAIR/F_smpsfaq.html
I hope this helps!
Matt Roberds
Alan P. Laudicina
David S. Pieczkiewicz wrote:
>Hello,
>
> I have a Silicon Graphics Indy with a Nidec power supply, which
>me outright replacements, but I am on a limited budget, and would first
>like to try my hand at repairing the dead supply myself, if possible.
The power supply for an Indy is extremely advanced, good luck fixing it.
Thanks,
Alan P. Laudicina
--
| Alan L. * Webmaster of www.UnixPower.org |
| Windsor Unix Users Group Founder: http://unix.windsor.on.ca/ |
| Personal Page: http://www.unixpower.org/alanp/ |
Ralf Beyer
I have a Silicon Graphics Indy with a Nidec power supply, which
appears to be faulty (machine won't boot). Various vendors have offered
me outright replacements, but I am on a limited budget, and would first
like to try my hand at repairing the dead supply myself, if possible.
supply, or similar models.
The last time one of the NIDECs failed
was due to a blown fuse (soldered in),
a burnt capacitor and a defect IC of
type 2SK1512.
If you want a schematic NIDEC says:
Release of schematic diagrams for this
power supply will require execution of
a non-disclosure agreement and payment
of a US$30 service fee.
Regards
Ralf....@dlr.de
German Aerospace Center (DLR)
Deutsches Zentrum fuer Luft- und Raumfahrt e.V.
Network
> FLU5-170-1-6560, with the following rated outputs:
>
> +5 VDC at 25A
> +3.3 VDC at 7A
> 5V AUX at 1 mA
> +12 VDC at 4.5A
> -12 VDC at 0.75A
Don't forget that the Indy power supply is similar to that of a
Macintosh, or ATX PC. The power button is soft touch, and the
machine can be powered down via a command thru IRIX or the boot
prom.
The motherboard obviously communicates with the power supply.
- tm
Lord Garth
nothing
with you about the various phases or voltages or current that is needed to
operate one of these outside of a drive. It is a big top secret with these
guys
and they claim the motor specs are unique to each manufacturer since each
manufacturer buys the entire production run of each type. Fortunately,
there
are only three wires on mine and I can scope a working unit to see the phase
relationship. So to hell with Nidec, who needs 'em anyway!!!
Jon
Network <nw...@krypton.engrs.infi.net> wrote in message
news:37B9D6...@krypton.engrs.infi.net...
Steve Bell
Network wrote in message <37B9D6...@krypton.engrs.infi.net>...
>> The particulars of the power supply: Nidec/Power General
>> FLU5-170-1-6560, with the following rated outputs:
>>
>> +5 VDC at 25A
>> +3.3 VDC at 7A
>> 5V AUX at 1 mA
>> +12 VDC at 4.5A
>> -12 VDC at 0.75A
>
>
>Don't forget that the Indy power supply is similar to that of a
>Macintosh, or ATX PC. The power button is soft touch, and the
>machine can be powered down via a command thru IRIX or the boot
>prom.
>
>The motherboard obviously communicates with the power supply.
>
> - tm
If anyone is familiar with the startup of a SGI power supply I'd be most
interested in knowing how its done. We repair most power supplies, and
startup on the bench all Apple, ATX, Power Computing and many more with soft
start power on. We'd like to accept SGI power supplies for repair, but
haven't seen one to date and am curious about its startup. I note the SGI
power supply has a +5V AUX 1 mA output, this is similar to Apples +5V TRKL.
This output should be there with mains applied to the PSU. If not trace
back. You could check to find if there is a PG (power good, could be
labeled PFD) line on the PSU output, then link the +5V AUX to the PG to see
if the PSU starts, but load its output first.
Re Power General. I ordered some schematics from them some years back for
standard power supplies as used in Cabletron hubs used by Sun, no problem.
When a power supply is an OEM model, as the SG unit will be, manufacturers
never release schematics, only to authorised repairers with the authority of
the OEM, and often then with non-disclosure agreements.
Steve Bell
Fernando Teixeira
David S. Pieczkiewicz wrote:
> Hello,
>
> I have a Silicon Graphics Indy with a Nidec power supply, which
> appears to be faulty (machine won't boot). Various vendors have offered
> me outright replacements, but I am on a limited budget, and would first
> like to try my hand at repairing the dead supply myself, if possible.
> I'm asking if any readers have experience with repairing this power
> supply, or similar models. Judging from what I've read and heard, Indy
> power supply failures are rather frequent, so I'm imagining there might
> be some common underlying causes.
> The particulars of the power supply: Nidec/Power General
> FLU5-170-1-6560, with the following rated outputs:
>
> +5 VDC at 25A
> +3.3 VDC at 7A
> 5V AUX at 1 mA
> +12 VDC at 4.5A
> -12 VDC at 0.75A
>
> There are no obviously faulty/burned/etc. components. I've made a
> few measurements, and it seems as though only one of the pinouts is
> giving any voltage (+5). However, I do not specifically know the
> pinouts for the supply itself, and am also wondering if this is one of
> those power supplies that has to have loads or other types of
1- Check the electrolitic capacitor C1(1uF 400V) and the resistor R5, is the
most frequently failure in that power supply.
2- Check the diode D14 (2 diodes on a TO220 case) and D11, they fails often.
Good luck
Fernando Teixeira
Tomasz Korycki
Hey, Fernando, would You know as much about R3k PS? By ITT, Model #
PEC4044B, rev F?