Opinion Poll: Bestec power supplies

[everell]

Three years ago, I made my first post on Badcaps, titled Bestec ATX-250 12E up and running. It was also the first power supply I fixed......and had to modify somewhat. After three years and much discussion.....and information, do the members of Badcaps still hate Bestec power supplies as much as three years ago?

Yeah, you have to remove that crappy glue (just like other brands).

Yeah you have to replace some crappy capacitors (just like other brands).

Yeah, the design of that 5vsb on the ATX-250 12E is crappy but works well when replaced with the DM311 pwm chip.

By the way, that first Bestec power supply I fixed is still working great in a Socket A machine.

[c_hegge]

Re: Opinion Poll: Bestec power supplies

Overall, I like Bestec. They aren't quite up there with Delta, but I'd quite happily use one after a re-cap.

[Wester547]

Re: Opinion Poll: Bestec power supplies

Bestec power supplies are not terrible.

They're not A+ grade but with a simple recap and with conductive glue amiss (unless they preferably use white glue) they can be good, and if need be, a relocation of the +5VSB diode. And, as everell mentioned, a severe modification to the ATX-250-12E's fatal issue. My only other issue with Bestec is that they like to use flyback designs on the +5VSB circuit and this means much more stress added to the already inefficient and stressful linear regulation of that circuit (thusly the reason why you don't see +5VSB rated at anything more than a few amps), especially when it doesn't receive airflow (when AC power is not removed and when it's plugged in). Added to the fact that Bestec like to use CapXon or Jamicon capacitors, it's understandable why they fail so quickly.

Bestec power supplies are still much, much better than truly cheap, Chinese power supplies which deliberately remove almost all that is necessary for an operational PSU. At least Bestecs can do their labeled rating with no problem, though it would have been nice if they had OPP too. Bestec have also moved on from the half-bridge topology, unlike so many other cheap Chinese PSUs. I don't think half-bridge is truly bad (though I dislike how the ripple frequency is double that of the mains by way of full wave rectification, so while that's not necessarily a problem for the PSU if the components inside are up to it, it means much more ripple not only going across the internal components but also going out, to my knowledge), but it says something if the truly lowest-end, cheap Chinese PSU manufactures cannot do much else successfully. I also like how Bestec use Jamicon fans. Granted they're sleeve bearing so they're not fantastic but they are certainly better than the nonames and better than ADDA.

I see Bestecs often used in OEM PCs, from Dell to HP Pavilion, so they must be half decent, I would think - my father has an HP Pavilion with an ATX0300D5WC in it (Rev: B so it has the green light to indicate ON or OFF status) and it never gets hot and blows out ample air, and has never once been unstable (going on a little over a year of usage now). It doesn't have any conductive glue, either, though haplessly +5VSB is flyback with the hot diode right next to a CapXon KF capacitor (2200uF/10V), so I know it will fail sooner than later. My only complaint with that PSU is the heavy inclination of +5V power as opposed to +12V power - it should be the other way around for a PSU of that ATX +12V revision. On the label it says the +5V rail can do 25 amps and the +12V rail can do 19 amps (18 for the +3.3V rail), and combined the +5V and +3.3V rails can do 175W, but when I looked inside, I found that the +5V rail has two STP3045CWs in parallel, the +3.3V rail one, and the +12V rail, only a STPS20H100CT! Note that this is a single transistor forward PSU so I think that's cutting it a little too close. That is the sort of configuration I would expect to see in a 300W PSU from 2001, not 2011. It should be the other way around - the +5V rail should have one STPS3045CW and the +12V rail two STPS20H100CTs.

My only other complaint about Bestec is that the capacitors they use on the secondary are often general purpose and have poor ripple ratings (add half-wave rectification to that and the ripple rating is even lower). They crossload easily because of that and could do better than that. But as stated, these PSUs can be quite fine once recapped and once the +5VSB circuit is modified a tad.

Sorry for the length of this post. In summation, though, I like Bestec. Actually, once you see just how truly horrific cheap Chinese PSUs can be, it becomes much easier to appreciate even the average PSU much more.

[ben7]

Re: Opinion Poll: Bestec power supplies

Bestec PSUs aren't that bad in my opinion - AFTER a re-cap!

From the factory, they are terrible, because they fry motherboards!

[everell]

Re: Opinion Poll: Bestec power supplies

I am very surprised at the response thus far........I expected some chairs to be thrown my way!

[Shocker]

Re: Opinion Poll: Bestec power supplies

Why don't you add an actual poll???

[momaka]

Re: Opinion Poll: Bestec power supplies

Bestec is okay in my book, though my preference certainly goes with HiPro, LiteOn, and Delta (in that order).

Reason why is because I often see Bestec use smaller heat sinks than HiPro, Delta, and LiteOn for the same wattage ratings. The brown glue is another big negative. Also, I noticed that many of the older Bestec designs have a linear self-loading circuit on the -12V rail that wastes more power than I think is necessary. And of course if you remove that circuit, the -12V rail goes a bit higher than normal - but I haven't had it cause problem. Another thing I dislike about Bestec is their use of general purpose or ultra-crappy (CapXon) caps. And lastly, I find Bestecs (at least the older ones) to be a little less efficient than HiPro, Delta, and LiteOn based on the heat they are throwing out the back.

But all in all, I don't mind using Bestec PSUs, especially if they are recapped and the brown glue has been removed.

I have the ATX250-12E's more mature brother - the ATX250-12Z which doesn't have the problems with 5vsb circuit. Overall happy with it. Currently, it's powering a GX270 motherboard with a 2.66 GHz P4 Northwood and Radeon 9700 video card. I use that computer very very rarely, so I can't comment on the reliability yet. In terms of performance, my 12Z does get a little warmer than my HiPros but it's okay overall.

I also have a Bestec ATX-1956D. That one also has a non-2-transistor 5VSB circuit and works good. Even though it's meant to be used with a 5V -based PC (or very light-weight 12V PC), it managed to power the above GX270 PC just fine.

[Wester547]

Re: Opinion Poll: Bestec power supplies

And lastly, I find Bestecs (at least the older ones) to be a little less efficient than HiPro, Delta, and LiteOn based on the heat they are throwing out the back.

There are a few reasons as to why your 250W Bestecs output more heat than your (Dell 250W?) Hipros, I believe. Clearly, you know your systems much better than I do so I cannot speak for them, but I can theorise why. :P First of all, the 250W Hipros you have, if I'm not mistaken, all have the common AD0812HS-A70GL, which is a high speed 80x80x25 fan from ADDA, rated at 3010 RPM/38.6CFM. Your 250W Bestecs probably have a weaker fan - JF08251SM (medium speed fan from Jamicon) - rated at 2500RPM/32.4CFM - so though your PSU's fans are obviously temperature controlled, it's clear from its specs that the latter one is quite a bit weaker so it doesn't remove heat from the PSU as effectively. Your Hipro PSUs also have much thicker heatsinks and a far more overbuilt primary and secondary, If I'm not mistaken, your Bestec 250Ws have 470uF input capacitors and a 4A bridge recifier - the 250W Dell Hipros of that time had either 560uF or 680uF primaries and 8A bridge rectifiers, and probably a much more powerful main switcher than that of the Bestecs you speak of (all these PSUs are single switch forward, I believe), along with secondary capacitors and rectifiers (most of which are TO-247 or TO-3P, on massive heatsinks) of much higher ratings (these Hipros also have -12V voltage regulators soldered to a smaller heatsink, which helps immensely). It also came to my notice that those Hipros have very thick secondary toroidal coils (and more than ample input filtering), thicker than the average. Hence the difference in crossloading you observed with both PSUs (the Bestecs crossloading easily, the voltage regulation of the Hipros being impeccable, and added to that, the use of DC-DC conversion on the +3.3V rail means much less noise and much cleaner output).

So even though those older Newton Powers/Deltas/Hipros/Liteons are below 80% in efficiency they are so overbuilt even with subpar brands of capacitors that they do not suffer in heat out because of lack of efficiency (and that's definitely why even Taiwanese brands last longer than usual in those PSUs - their design is not stressed much at all, sort of similar to how crappy brands hold up on the primary side in non-APFC PSUs because input capacitors aren't as stressed). Clearly, when they put 250W on the label, they meant 250W @ 50C ambient temperature and 95% humidity, I would guess... something else I would also like to add is that while Delta and Lite-on obviously overbuild their PSUs, I have noticed that Hipro does not do so as much excepting the Dell PSUs of the aforementioned time and much older PSUs (built for Compaq, from 2001-2002). I've seen many Hipros with average heatsinks that aren't nearly as overbuilt as the above mentioned for their rating. This doesn't make them terrible PSUs - they can still do their rating (but probably more like at 40C/80% humidity and with the fan revving up much more, and some of these Hipros are only rated up to 40C room temperature, actually...) but it does mean that the crappy capacitor brands will not hold nearly as well in the PSUs and neither will the sleeve bearing fans, along with augmented heat output.

Sorry for that huge rant and huge wall of text. If I'm not mistaken, some more modern Dells actually have Bestecs as well. Yes, though, it can be concluded that the Bestecs without the two-transistor +5VSB circuit are average to decent at best.

[Luposian]

Re: Opinion Poll: Bestec power supplies

I have an old Bestec 250 12Z. It runs ok, but was shutting down when external temps got too high (my workshop gets over 90F in the summer). I opened it up, hosed it out, and let it dry and plugged it in and it seems to run a little better now, since all that insulating dust is gone. But what I'm wondering is... can you improve this PSU beyond it's current design? I know new, Japanese caps will likely improve some things (like ripple), but can you upgrade other components to improve it more? I love to tinker with things and knowing I can spend a little money and effort to make something BETTER, is always right up my alley.

[Pentium4]

Re: Opinion Poll: Bestec power supplies

I think the 250-12Z is a nice little power supply. Although I think they suffer a lot from the glue going conductive, so you will want to remove all of that.

What I have done with some of those lame punch out exhaust grilles, is cut the inner grille off and replace it with a wired grille like this to increase the airflow a little bit.



Is the system you're using mostly 12V?

[Luposian]

Re: Opinion Poll: Bestec power supplies

I think the 250-12Z is a nice little power supply. Although I think they suffer a lot from the glue going conductive, so you will want to remove all of that.

What I have done with some of those lame punch out exhaust grilles, is cut the inner grille off and replace it with a wired grille like this to increase the airflow a little bit.



Is the system you're using mostly 12V?

I'll look into the fan suggestion. Couldn't hurt. Airflow never does... of course, I suppose installing a Tornado in there would be overkill, right? Do they still even make those super-fans (sounds like a dust buster)?

My systems are the usual CPU and DVD drive and hard drive and built-in video. So, whatever voltages those use.

I asked over at JonnyGuru about jumpering the voltage switch, so that it was permanently 110V. I'm never leaving the US or selling it overseas, so why worry? That switch surely saps valuable power!

Or, does doing that, make the Bestec 250-12Z go...

[cheapie]

Re: Opinion Poll: Bestec power supplies

Do they still even make those super-fans (sounds like a dust buster)?

You mean like the 48V Delta fans that move full cans? Although those sound closer to jet engines...

[bobbyrae]

Re: Opinion Poll: Bestec power supplies

What I have done with some of those lame punch out exhaust grilles, is cut the inner grille off and replace it with a wired grille like this to increase the airflow a little bit.

From an ideal air flow point of view (aesthetically too), I have always agreed with this and have tried that once or twice. In practice, however, particularly with temp-controlled fans, I don't think it actually makes enough difference to make it worth it.

[Pentium4]

Re: Opinion Poll: Bestec power supplies

From an ideal air flow point of view (aesthetically too), I have always agreed with this and have tried that once or twice. In practice, however, particularly with temp-controlled fans, I don't think it actually makes enough difference to make it worth it.

Yeah I know it doesn't make a huge difference but it does indeed look a lot better