Retro comparison: Antec SP-500 and SP-400

[LDSisHere]

I have to admit I have some kind of strange fascination for Antec power supplies. Maybe because I have bought and thrown away so many in the past or maybe because they are so close to being decent supplies yet always seem to fall short. Whatever the reason, I recently acquired an SP-500 and SP-400 with their warranty seals still intact so I thought it would be interesting to see what separated the 500W model from the 400W.

I eventually plan on recapping in addition to 5vsb testing and modifying both of these supplies.

I am going to make separate posts for each of the supplies so it will be easier to keep track of which is which.

[LDSisHere]

Re: Retro comparison: Antec SP-500 and SP-400

SP-500

Even though I knew this supply had bad caps I still had to see how much functionality it still had left in it. Surprisingly the 5vsb still had life in it with approximately 4.93V. The power supply would turn on and the three main voltages were within the ATX specifications. I am sure the ripple was not, but I have not bothered to try testing it. The exterior of this supply differs from the SP-400 by having modular connections available which reduces the mass of wires exiting the supply.

The circuit board in this supply is marked revision A. The main input caps unexpectedly appear to be Panasonic brand unless they are fakes rated at 1200uF 200V. The main rectifier marked KBU 10 is rated for 10A. It uses two main switching transistors marked 2SC3320 rated at 400V 15A. I noticed that the casing of the one on the right does not look to be in good shape. The “main” 5vsb transistor is a 4N60 which is not a surprise one way or the other.

The diodes on the secondary are STPS4045 rated at 40A@45V for the 3.3V and 5V. For the 12V they went with two diodes, MBR20100 each rated for 20A @ 100V. According to the label, the total Amp rating for the 12V output of this supply is 36A so there is not much of a margin for error.

The fan controller board has a sticker on it indicating it is for a 500W model but it is hard to see in the picture.

[LDSisHere]

Re: Retro comparison: Antec SP-500 and SP-400

SP-400
I also tested the operation of the SP-400 as I had the SP-500. The 5vsb was not stable by any measure, it was making my meter go a little nuts, I mostly recall it reading 2.63V. The power supply was also powering off and on continuously when power was applied. Pressing the on button of my ATX tester surprisingly would turn on the supply, releasing the on button would cause the supply to once again cycle on and off. Like the SP-500, when the supply was on, the three main voltages were good.

The circuit board in this supply is marked revision B, but I have not yet found where it differs from revision A. So far I have found one difference between the revisions. The main input caps on this supply did not disappoint me like the ones in the SP-500 did, as this one has my favorite brand of caps, genuine Fuhjyyu 820uF 200V. However, I think they may be fakes since there is no sign of bloating or leaking from them. The rectifier in this supply is a KBU8 which is rated for 8 Amps, 2 amps lower than the SP-500. The two main switching transistors are marked D4515 which are 400V 15A which is the same rating as what was in the SP-500. The main 5vsb transistor is a 4N60 as I expected.

The diodes on the secondary are STPS3045 rated at 30A@45V for the 3.3V and 5V. This is the most significant difference yet between the two supplies. For the 12V they went with two diodes, MBR20100 each rated for 20A @ 100V which is the same as the SP-500.

Similar to the SP-500, the fan controller board has a sticker on it indicating it is for a 400W model. I did a little probing but could not tell there was any significant difference between the two boards. There may be a slight variance in the resistor values but nothing obvious. I intend to examine this more closely when I have the time.

One of the things I find most interesting is that the transformers all appear to be identical between the two models, only the tape color is different. This means that it would not be difficult to modify the SP-400 to perform like a SP-500.

[eccerr0r]

Re: Retro comparison: Antec SP-500 and SP-400

The shocker is that the SP-300 is of a different structure, oddly enough. The SB-350/SL-350 is similar to my SP-400 but not exactly...

I wonder if it's worth to hack the PSUs to a higher rating... I would have thought the inductors should be different as it costs more for the copper in them to have thicker windings... Semiconductor costs, of course is the other major difference...

[LDSisHere]

Re: Retro comparison: Antec SP-500 and SP-400

The copper on the secondary looks the same to me on both supplies but I have not done any in depth analysis of it. I will take a better look at it to see if there is a difference between the two in this area.

I do not know if it would be worth it to spend money to upgrade the SP-400 but if the parts are just in your parts bin then I do not see why not. Unfortunately, I have not been able to find anything to use towards this idea.

[eccerr0r]

Re: Retro comparison: Antec SP-500 and SP-400

I highly doubt the tracks are different as it's cheaper to keep just one flavor of the board. Unfortunately I don't have the parts to upgrade it -- likely the only thing needed are all the rectifiers (pri and sec), possibly switching transistors (and possibly its drive components). I can't think of anything else that really must change to bump the power output if the transformers are the same...

[c_hegge]

Re: Retro comparison: Antec SP-500 and SP-400

I've only ever seen one SP-500. Unfortunately, the ID10T end user put up with the random crashes and stability issues for ages until the PSU eventually destroyed itself, and wrote his PC off. I wasn't prepared to put the time and effort into getting it going.

As far as the transformers are concerned, they do appear to be the same across the SP series. The colour of the tape is not by any means model-specific. The most common model I've had to work on is the SP-350. Some of those had yellow transformers, while others had green.

Another interesting point is that the last few Antec SP-___ units I've had to work on had almost entirely Teapo caps on the secondary side (except for maybe one or two smaller ones). The two 5vsb caps were always bad. The others were failed on some of them, but not on all. Needless to say, I recapped them regardless.

Another common problem is the front fans (the thin 10mm ones) I usually replace them with 25mm fans and have them sticking out the front.

[Pentium4]

Re: Retro comparison: Antec SP-500 and SP-400

Very cool. Thank you for posting these, interesting to see the differences. I have an SP450 and SP500 (which I tihink is a newer revision), I can post the pictures of the internals if you want. The SP500 has the same looking input "Panny" capacitors but both are bulged badly, I would guess that they might be fakes

[c_hegge]

Re: Retro comparison: Antec SP-500 and SP-400

^
Either that, or using 85*C caps that touch those ultra-hot primary heat sinks doesn't do them any favours

[ben7]

Re: Retro comparison: Antec SP-500 and SP-400

I think I recall someone else on this forum had a bulging panasonic capacitor on their psu ... I'm quite sure it was an Antec too.

[eccerr0r]

Re: Retro comparison: Antec SP-500 and SP-400

All my older/working antecs have fu****u's... I'll never remember the correct spelling of those, except those three letters I think are right...

Edit:

My working Antecs: SP-300 (was repaired), SP-350 (semi-preemptively repaired), SP-400 (was repaired), NeoHE 430 (so far so good, never opened)

My Antec project: fried Truepower Trio 650...

[cheese007]

Re: Retro comparison: Antec SP-500 and SP-400

I think I recall someone else on this forum had a bulging panasonic capacitor on their psu ... I'm quite sure it was an Antec too.

Think I know what you're talking about, but iirc it was a Topower.

[ben7]

Re: Retro comparison: Antec SP-500 and SP-400

Think I know what you're talking about, but iirc it was a Topower.

Ah, it probably was. Strange since I think I recall the primary side looking just the same as the antec with panasonic primary capacitors above.

[shovenose]

Re: Retro comparison: Antec SP-500 and SP-400

I think it was me. I had an SP with one of the two pannys bulged.

[lti]

Re: Retro comparison: Antec SP-500 and SP-400

I've seen both Antec and Topower PSUs with bad Panasonics.

[LDSisHere]

Re: Retro comparison: Antec SP-500 and SP-400

I wonder if it's worth to hack the PSUs to a higher rating... I would have thought the inductors should be different as it costs more for the copper in them to have thicker windings... Semiconductor costs, of course is the other major difference...

The copper on the secondary looks the same to me on both supplies but I have not done any in depth analysis of it. I will take a better look at it to see if there is a difference between the two in this area.

In this reply I was referring to the copper on the inductors appeared to be the same, however it was not very clearly stated.

There is an actual difference on the PCB between the two which I suspect is the reason for the revision change. This can be seen in the attached pictures.

Very cool. Thank you for posting these, interesting to see the differences. I have an SP450 and SP500 (which I tihink is a newer revision), I can post the pictures of the internals if you want. The SP500 has the same looking input "Panny" capacitors but both are bulged badly, I would guess that they might be fakes

If you get a chance I would like to see some pictures of these supplies. I would like to see how they differ from mine.

I think I recall someone else on this forum had a bulging panasonic capacitor on their psu ... I'm quite sure it was an Antec too.

I have had bulging Panasonic primary caps on several different power supplies but it seems like most of those were Antec branded.


I have finished recapping the SP-500, I have not yet attached the heat sinks or primary caps. I have removed the caps from the SP-400 fan board but that is where I have stopped until I get more time. I forgot how many little caps these old Antec's have in them. And in case anyone is wondering, I do replace them all if I am going to the trouble of recapping the supply. Once I get them recapped I am going to do some 5vsb testing with the original design before modifying them to work with a NCP1200 or NCP1216.

[dmill89]

Re: Retro comparison: Antec SP-500 and SP-400

I'd probably do the "fan Mod" on these too (2.2K ohm resistor in parallel with the original thermistor which) to keep it from cooking the caps.

Here's an SP-350 I did a while ago:
https://www.badcaps.net/forum/showthread.php?t=19499

[Mrx3750]

Re: Retro comparison: Antec SP-500 and SP-400

Antec had great power supplies back when Seasonic made them, and even now I'm using an Earthwatts 500 watt PSU in my main PC.

[dmill89]

Re: Retro comparison: Antec SP-500 and SP-400

Antec had great power supplies back when Seasonic made them, and even now I'm using an Earthwatts 500 watt PSU in my main PC.

Antec's current power supplies are made by SeaSonic (HCG < 700W, NEO ECO), Delta (HCG 700W +, HCP, EarthWatts), and FSP (Basiq BP/VP).

All of them are pretty good (The Basiq series is nothing spectacular, but they are budget units and are decent given their price point). The problematic Antecs were the much older ones made by CWT (especially the SP series) that were loaded with Fuhyyu capacitors. All of these are long discontinued and Antec hasn't used CWT as an OEM for many years.

[LDSisHere]

Re: Retro comparison: Antec SP-500 and SP-400

I was finally able to get both of these supplies completely recapped with the exception of the main HV caps. Normally I replace Fuhjyyu on sight, however the ones from the SP-400 tested good, I do not have anything on hand to replace them, and I do not know if this supply will ever be used for anything other than experiments so I am going to use them for now. The only difference between the two supplies capacitors other than the brand was on the 3.3V rail. The SP-500 had a 4700uF & 3300uF 6.3V capacitors where the SP-400 had two 3300uF 6.3V capacitors.

After the recap I checked all the output voltages and did some initial testing of the 5vsb output. I have attached the results as images. The only load on the supply for checking the rail voltages was my ATX tester. The 5vsb current is actual current measured by my Fluke 175. None of the results are very surprising. I did not push the 5vsb much past the rated 2A and for these readings I only had it on long enough to get these readings. I have not yet decided on how I am going to torture test the stock 5vsb circuitry before I modify it so for now I did not want to damage it.