Power Supply Centuriontech or Exxos

[Bama]

Hi Y’all,

I am looking to purchase five new power supplies (520STFM, 1040STE, Mega ST4, Falcon, & Falcon MKX).

Does any one have experience with Centuriontech or Exxos PSU’s?
I would really appreciate your opinions and comparisons.

Thanks,

[joska]

I have no experience with either, but judging from the technology used I would choose the Centuriontech PSU. exxos' PSU use a big, heavy transformer while the Centuriontech PSU is a modern switch mode design and also cheaper. While a toroidal transformer works just fine, it's very heavy and they can also hum quite a bit when the washers degrades.

Personally I wouldn't have bought any of them. A PicoPSU and an external brick leaves a lot more room for internal add-ons and also moves the heat source to the outside of the cabinet. But this needs modifications to the PSU (or a custom cable) and also some bracketry, so not as simple as installing one of the above.

[Bama]

PicoPSU would certainly be less expensive.

A PicoPSU and an external brick leaves a lot more room for internal add-ons and also moves the heat source to the outside of the cabinet. But this needs modifications to the PSU (or a custom cable) and also some bracketry, so not as simple as installing one of the above.

Any long term problems from using a PicoPSU?

Are there modern part numbers for the connector plugs for the different STFM, STE, Mega and Falcon030 motherboard power pins?

[sety]

Are there modern part numbers for the connector plugs for the different STFM, STE, Mega and Falcon030 motherboard power pins?

https://www.jaycar.com.au/8-pin-0-156-header-with-crimp-pins-3-96-pitch/p/HM3438

Don't scrimp on getting the correct, good quality crimp tool. You don't want a power line coming out and striking your mainboard.

Cheers

[joska]

Any long term problems from using a PicoPSU?

As long as you buy a PSU of reasonable quality I can't see what that could be. I've used PicoPSU's in several Ataris for a few years now. I have an old X-BOX 360 powerbrick that delivers huge amounts of stable 12V (150W or so), I'm using this to power up to three Ataris at once. Our Ataris use a lot less power than people think, even my Falcon with Afterburner, graphics card, real floppydrive and a spinning disk use less than 25W.

[mpattonm]

Stock ST(*) motherboard draws 1,6A from 5V rail and 0,25A from 12V rail. Falcon draws 1,67A from 5V rail and same 0,25A from 12V., these values are w/o FDD & HDD. You can use these values to calculate your configuration, if you decide to go for PicoPSU.

[stormy]

Surely you should be choosing quality in those machines. Also there must be a good reason for exxos using that style of transformer, I think it would provide smoother power.

[Bama]

Agreed, I absolutely want quality in my machines.

Another question, if I replace the PSU’s, then will all of this new clean power harm the still original motherboard capacitors?

[joska]

"Smooth power" sounds like hifi voodoo to me, and I'm pretty sure that a transformer wouldn't help here as it's output is still AC and has to be rectified and regulated... Any modern ATX PSU of decent quality is more than capable of powering our ancient computers.

The real advantage of these PSU replacements is that they are more or less drop-in replacements. Installation is straight-forward and you keep original functionality. But as PSU's they are not better than the average ATX PSU designed to power much more sensitive computers than our old sh... stuff.

[joska]

Another question, if I replace the PSU’s, then will all of this new clean power harm the still original motherboard capacitors?

No. But if your ST hasn't been used for many years you should inspect it thoroughly before you power it up. Although I have never seen it myself in an Atari, old electrolytic caps can leak (and damage the PCB) or simply short out.

[Bama]

Another question, if I replace the PSU’s, then will all of this new clean power harm the still original motherboard capacitors?

No. But if your ST hasn't been used for many years you should inspect it thoroughly before you power it up. Although I have never seen it myself in an Atari, old electrolytic caps can leak (and damage the PCB) or simply short out.

Cool, thanks for educating.
I’m curious I’ve read the warnings on this forum about potential damage from a failing PSU but what about known occurrences of Atari motherboard damage if not recapped?

[joska]

Ataris generally don't suffer from broken capacitors, atleast not yet. At some point they will start to fail though. If you're competent it does not harm to replace them just to be sure. If you're not competent there is a much higher risk for damage from the "recap" process than from old caps

[dhedberg]

Some talk about the exxos PSU vs Centuriontech PSU here: https://www.exxoshost.co.uk/forum/viewt ... =60#p11093
Seems like the Centuriontech PSU is not quite up to the task of powering a CT2 (powered by the 12V rail). In general I'd say the Centuriontech PSU was designed for providing the current needed by stock machines and nothing else, while exxos CPU is capable of powering more add-ons. If keeping the machine in an "original" state is NOT of importance I'd say go for a PicoPSU. Personally I installed PicoPSUs in my Falcon030 and C-Lab MK2 a couple of years ago to get rid of the primary heat source in those machine, the internal PSU.

[mikro]

Some talk about the exxos PSU vs Centuriontech PSU here: https://www.exxoshost.co.uk/forum/viewt ... =60#p11093
Seems like the Centuriontech PSU is not quite up to the task of powering a CT2 (powered by the 12V rail).

Just not to make it sound like "Centuriontech is crap, go for Exxos if you want a serious PSU" I must add that this is only our preliminary conclusion. It happened twice, yes, it happened after I closed the case, yes but that is all we know. Pavel is looking at it right now - I will post an update as soon as we know more.

Plus, CT2 itself is quite special so I'm pretty confident all the "normal" devices like HDDs, CD ROMs, Goteks, CosmosExes etc will work just fine (as they have so far).

[joska]

Personally I installed PicoPSUs in my Falcon030 and C-Lab MK2 a couple of years ago to get rid of the primary heat source in those machine, the internal PSU.

Exactly. Even in a completely stock ST/Falcon the PSU gets quite warm. Heat is bad for the plastic case, it reduces the lifespan of capacitors and the repeated heating/cooling cycles can cause socketed chips to get loose or questionable soldering to crack.

[Greenious]

I would also like to add that I personally try to avoid fitting PSUs with way more power than needed. In case of a short or other mishap, it can mean the difference between a relatively easy repair and a heap of smoldering electronics and plastic. Some replacement PSUs also lacks proper specs, which always make me think twice about using them, and there is also, atleast in sweden, certain requirements regarding grid-connected devices such as PSUs, if they, for example, cause a fire (heaven forbid), you could end up with an invalid insurance claim if they find they are not up to standard. Atari's original PSU's may seem ... inadequate or inferior to some, but they have passed the tests.

Given the relative small power requirements of Ataris in general, I too like the small PicoPSUs over other options, but most of my ataris still run off the original PSU's, of which some has been recapped.

[tzok]

I have fitted a Mean-Well RT-65B in my STf. It barely fits there, but works just fine:

[C-Rem]

hi ... i agree with tzok : i've used a smaller one NED-35A here :

viewtopic.php?f=15&t=34515

Cu

[Robber]

What I always wanted to know is: Is the fan for cooling the processor or for cooling the PSU? I bought a Mega ST4 long time ago and as I later found out the the fan and metal casing inside were missing. After 20 minutes the ST4 got real hot, started to stutter and then crashed. Putting a fan and a spare metal casing brought everything back to normal.
I want to silence my ST4 's and Mega STE by putting a Pico PSU's inside and get rid of the fan. Is this possible?

[dhedberg]

The PSU and the hard disk are generating the most heat by far and will cause the overall temperature inside the case to increase to the level where the chips will run too hot. Remove the PSU and hard disk and you should be good to go without a fan. Today there's a good selection of extremely quiet fans though, so you could also choose to replace the original fan.

[tzok]

Today I've got an RD-50A and it fits even better:

[Rustynutt]

Looks nice

[MiggyMog]

They seem be reasonably cheap too. I was watching a video of one being fitted to a mega ST and wondered if they fit in regular sandwich case. I was wondering how would these behave with regard to noise, interference extra peripherals etc? Seems like a good option?