Dell power supply with generic motherboard

[pfrcom]

I bought some new Dell HP-P2507FWP power supplies, guessing they were Hipro built, to use with generic motherboards

They appear to have standard pinout, judging by wire colour coding and measured voltages

Each supply will power up if I connect it to a HDD and FDD for load, then on its 20-pin ATX connector, short the PSON wire to a GND wire beside it

But after plugging its ATX connector onto a motherboard, as well as the 12v connector, nothing happens when I touch a screwdriver tip to the motherboard's PwrSw pins

Have tried with an Abit SG72 board, as well as an Intel D845GVAD2

Same procedure with a generic ATX supply - comes on straight away

Pity - the HP-P2507FWP appears to be a quality supply, especially compared to some of the flimsy junk where bling is more important than function

[kc8adu]

Re: Dell power supply with generic motherboard

i bought a huge lot of these cheap with bad arcon caps.
they all power up and pass the test with one of those lcd psu testers but all are full of blown caps.is there such a thing as a good arcon or asiacon cap?
pop the top and have a look.
ones i recapped work fine in anything i put them in.

[pfrcom]

Re: Dell power supply with generic motherboard

Thanks

Sounds right

The one cap I can see through the grill does look like Arcon on its side

And although new, the power supplies have QC stamp saying 2004

Bad caps don't necessarily have to be used, to be BAD

[linuxguru]

Re: Dell power supply with generic motherboard

These are easy to recap, and bulletproof when recapped. One of the best P-PFC units around, though limited to a very honestly-rated 250W.

Recap all the secondary caps (on both auxiliary and main sections), as well as the 47uF or 100uF/50v next to the auxiliary flyback - I have used NCC LXA 100uF/35v, Elna RJJ 100uF/35v or Nichicon PW 100uF/80v at this location - the last is probably the best all-round cap here, rated at 5000 hours.

For most other locations, Nichicon PW, NCC LXZ or Panasonic FC will be fine. I also re-lube or replace the ADDA sleeve-bearing fans with NMB ball-bearing fans if necessary.

Rectifiers are fine, primary caps and everything else are fine. It should be good for a decade of use after recapping.

[pfrcom]

Re: Dell power supply with generic motherboard

The show-stopper seemed to be a faulty Arcon 1000uf 10v capacitor near the transformers - not always bulging, but always measuring abnormal on Dick Smith ESR meter
The example in the first picture is starting to leak electrolyte, with the second picture showing a faulty Arcon 4700uf 10v in the secondary

[pfrcom]

Re: Dell power supply with generic motherboard

Will horrify the electronics experts, but replaced the 1000 with a Chemicon LXF 820uf 25v salvaged from an IBM AS/400 disk controller over 10 years ago ! - and the 4700 with a Chemicon LXZ 4700uf 6.3v salvaged from a more recent motherboard
The first picture shows the 820 in place, with spare replacements sitting on the heatsink, and the second picture showing the 4700 in place
Wore safety spectacles for first power up, and after power up touched casing with back of fingers, in case something blew or it was live – but all was well
Thanks KC8ADU and LinuxGuru for your advice – would like to replace the lot, but cost and (lack of) availability of decent capacitors in Australia makes it not worthwhile

[linuxguru]

Re: Dell power supply with generic motherboard

NCC LXFs are outstanding for their endurance (rated for 10k to 15k hours), and so are LXZ. All the large Arcons/Asiacons are doomed to fail, so you might as well replace them at the outset. That 1000/10 is probably on +5Vsb or the controller power rail, so it's important - and so is the 47/50 or 100/50 on the primary side near the auxiliary flyback transformer.

To me, these are among the most worthwhile PSUs to repair - bad ones are available in volume, and the success rate after recapping is 100%. They're P-PFC as well, which is great for systems connected to UPSes.

[PCBONEZ]

Re: Dell power supply with generic motherboard

There are several Auzzie members here that can tell you where to get caps down under.
davmax and stevo1210 come to mind. Both are frequent visitors.
Look them up in members list and send them a PM.

[pfrcom]

Re: Dell power supply with generic motherboard

Questions:

1. Is there a problem (or hazard) using a capacitor that could be 15 years old, also lower capacitance but higher voltage (the LXF 820/25), to replace the Arcon 1000/10

2. Ditto for the 4700/6.3v LXZ replacing the 4700/10v Arcon

3. As a general rule of thumb, would it be OK to use 6.3v reputable brands to replace 10v Arcons - I guess they're handling 5 or 3.3 v

4. Do the 16v need to stay at 16v - I guess they're handling 12v

5. Is it undesirable to use low ESR Samxon GC or GD as replacements

(I've bought from Big Pope on these forums before, but he can supply only GC or GD in most capacities needed - I guess RS or GT would be preferable)


The original Arcon B.O.M. is:

4700uf 10v 1off 12.5x30

3300uf 10v 1off 12.5x30

3300uf 16v 2off 12.5x30

2200uf 10v 3off 10x25

1000uf 16v 1off 10x20

1000uf 10v 1off 10x17

470uf 16v 1off

100uf 50v 1off

[PCBONEZ]

Re: Dell power supply with generic motherboard

Last I looked he also lists RS series which should do fine in a PSU.

[pfrcom]

Re: Dell power supply with generic motherboard

RS series were not available in most of the required capacities

[pfrcom]

Re: Dell power supply with generic motherboard

And neither were GT - I asked for RS and/or GT originally

[linuxguru]

Re: Dell power supply with generic motherboard

>1. Is there a problem (or hazard) using a capacitor that could be 15 years old, also lower capacitance but higher voltage (the LXF 820/25), to replace the Arcon 1000/10?
>2. Ditto for the 4700/6.3v LXZ replacing the 4700/10v Arcon?

In both these specific cases, it's probably OK. LXF and LXZ are non-aqueous (they use quarternary ammonium salts in organic solvent, as electrolyte), so there isn't any water to evaporate and dry out. The organic solvent also evaporates, but at a much slower rate, which is why the shelf-lives as well as endurance specs of both these series are outstanding (7k-15k hours at 105c). At normal operating temperatures of <60c, they should last decades. That IBM AS/400 was probably sitting in an 18c AC computer centre with raised floors and excellent airflow, under which conditions the LXF should last a century.

>3. As a general rule of thumb, would it be OK to use 6.3v reputable brands to replace 10v Arcons

Yes, it's OK. As a matter of abundant precaution, I try to use 10V caps inboard (on the rectifier side of the pi-filter) and 6.3V caps outboard (on the output rail side), but 6.3V caps can be used everywhere.

>4. Do the 16v need to stay at 16v - I guess they're handling 12v

16v, 25v or 35v should be fine. You'll find that it's easiest to find 16v caps that have the same outer diameter as the original. It will be harder to find a 3300/25, low ESR, in 12.5mm.

>5. Is it undesirable to use low ESR Samxon GC or GD as replacements

I haven't tried them, but other forum members have used them with some success. In order of decreasing priority, I have used non-aqueous Nichicon PW/PS/PR/PL/PM, NCC LXF/LXZ/LZY/LXV/LXA, Panasonic FK/FC. Aqueous electrolytics like Panasonic FM/FJ, Rubycon ZL/ZLH/MBZ/MCZ, NCC KZE and Taicon/Nichicon HE/HD/HM as a last resort, preferably at outboard locations and locations with good airflow.

At the risk of repeating myself, that 100/50v is important - stick with a non-aqueous cap for that location, and 35v is sufficient (I have measured as well as analyzed the auxiliary flyback circuit).

There's a Nichicon PW 100/80v that's perfect, but you may have difficulty fitting it at that location. Numerous choices exist at 35v.

[pfrcom]

Re: Dell power supply with generic motherboard

Thanks LinuxGuru, for the effort to address my specific questions

I should have been more clear with the question "Is it undesirable to use low ESR Samxon GC or GD as replacements"

Most of the capacities required are not available from Big Pope in long life Samxon RS and GT series, but he can supply low ESR GC and GD

I have used Samxon GC and GD from him on some motherboards, with good outcomes - also, when they were available locally, Samxon GF

But I was under the impression that GC and GD are not a good choice for power supplies

[PCBONEZ]

Re: Dell power supply with generic motherboard

GC and GD are not the best choice for power supplies but if that is all you can find they will work.