Delta DPS-300JB G Rev 02 300W

[JEWilson]

Hi

These come with the Intel SC5000 chassis. I have of 6 of these.

Have tested two extra loose PSU (acquired as spares) with PSU tester (for what that's worth).

The first PSU tester reports no PG.
The second PSU tester (has an LCD display), similarly so.

Is this by design?

I recall the front panel wiring for these chassis (a 9 pin flat ribbon cable) differs from normal ATX.
Also, as soon as power is applied - the fan will start and
stay on at a low rpm. To start a SC5000 system, you then have
to press the front panel power start button - this starts
the system in full.

I would like to establish if I have a problem before having to
pull another (known good and working) out of a server.

Any advice, help and insight greatly appreciated.

[999999999]

Re: Delta DPS-300JB G Rev 02 300W

I have not examined one of those but have a DPS-300BB (FWIW) a while back.

I would not rely on a PSU tester or at least not alone. At least if you want to use it, determine the amount of load it places on each rail, and what it's threshold is for power-good pass/fail.

Power good needs to change logical state from
< 0.4V (off/bad) AND >= 2.4 to (~) 5V (on/good)

If your tester has a higher threshold than 2.4V, that alone could account for it. Better question is, when the major rails have enough load to keep the PSU running and regulating ok, does the output stay in the required range?

You write that the fan starts but where is it plugged in? If there's a special proprietary fan connector from the PSU (which does not appear on a DPS-300JB "standard" design datasheet (which Intel could have easily re-spec'd, but I would hope that changed the model name if they did) that could account for it, or simply the board has 5VSB to one fan header.

To back up a moment, do you have any suspicion they'd failed and that's why you're testing? Normally I would write, attach a larger known load then measure the change in state of the Power good signal comparing AC-connected/off state to full-on state to ensure it flips between < 0.4V and between 2.4 to 5V, BUT a common load I sometimes suggest is a couple of hard drives, which may not be sufficient with this particular PSU unlike some others.

One notible thing I recall about the DPS-300BB is that it will shut off if there isn't sufficient load on it's 3.3V rail. There were some deals on these a few years back and it seemed like a large % of the brand new PSU were defective but they were simply being tried in nex-gen., non-server systems which didn't put any load on 3.3V rail and so adding a ~ 10 Ohm load resistor to the 3.3V rail did the trick keeping them from triggering the OVP circuit.

I'm suggesting that if they power on with a load and output voltages measure ok, it's unlikely the Power-Good logic level signal would go bad, more likely a flaw in the way the testers are determining pass/fail.

[JEWilson]

Re: Delta DPS-300JB G Rev 02 300W

Hi and thanks

The matter of the PSU fan.
It does not have any fan leads per se to connect to a mobo header.
When an IEC plug is inserted to the PSU and that plug is powered
on at the mains - the PSU fan will spin up at a low rpm. The PSU
will start the system proper when the momentary switch at the SC5000
front panel is pressed.

As I rec'd these particular PSU as spares - I do not know their condition or state and wrongly supposed both of the PSU testers I possess would
suffice for establishing any immediate problems.

As I am establishing service records for those PSU I have at my
place of work, these Deltas amongst a number of others were
given the once over with the PSU testers and were cleaned
and physically inspected.

Of course, this is no equivalent to a full electrical inspection
as is required by insurance companies and law and is only
a starting point.

I will conduct further research on these PSUs and get back to you
on this

Regards and thanks for your consideration