The only consequence of using PFC to the PC owner is that it makes the system incompatible with the less costly UPS units.
It does not improve the efficiency of the system. It improves the efficiency of your power meter and the power grid.
It came upon us by laws passed in the EU that were pushed through by EU power companies.
.

TELVM wrote:

Enermax NAXN ENP500AGT recapping

This is a budget PSU just above the 'passable' mark that uses the ubiquitous CWT GPA platform (APFC, two-transistor forward and group regulation.

Looks Good.

PCBONEZ wrote:

The only consequence of using PFC to the PC owner is that it makes the system incompatible with the less costly UPS units. It do […]
Show full quote

The only consequence of using PFC to the PC owner is that it makes the system incompatible with the less costly UPS units.
It does not improve the efficiency of the system. It improves the efficiency of your power meter and the power grid.
It came upon us by laws passed in the EU that were pushed through by EU power companies.
.

It also makes it impossible to nuke the PSU by improperly setting the mains selector switch.

gdjacobs wrote:

PCBONEZ wrote:

The only consequence of using PFC to the PC owner is that it makes the system incompatible with the less costly UPS units. It do […]
Show full quote

The only consequence of using PFC to the PC owner is that it makes the system incompatible with the less costly UPS units.
It does not improve the efficiency of the system. It improves the efficiency of your power meter and the power grid.
It came upon us by laws passed in the EU that were pushed through by EU power companies.
.

It also makes it impossible to nuke the PSU by improperly setting the mains selector switch.

Explain how.

It's kind of irrelevant to many newer PSUs because they''ve been moving from the switch to a wide range input with no switch.
I would still like to know how PFC prevents overvolting the front end of PSUs with the switch.
.

PCBONEZ wrote:

Explain how. […]
Show full quote

Explain how.

It's kind of irrelevant to many newer PSUs because they''ve been moving from the switch to a wide range input with no switch.
I would still like to know how PFC prevents overvolting the front end of PSUs with the switch.
.

That was what, with my tongue in my cheek, I was referring to. APFC designs with full range input.

I'll just wait for the club MC to escort me off the stage.

gdjacobs wrote:

PCBONEZ wrote:

Explain how. […]
Show full quote

Explain how.

It's kind of irrelevant to many newer PSUs because they''ve been moving from the switch to a wide range input with no switch.
I would still like to know how PFC prevents overvolting the front end of PSUs with the switch.
.

That was what, with my tongue in my cheek, I was referring to. APFC designs with full range input.

I'll just wait for the club MC to escort me off the stage.

I get you now.
With APFC there is no switch so can't put a switch in the wrong position.

I was thinking about PFC in general, not specifically APFC.
.

PCBONEZ wrote:

TELVM wrote:

Enermax NAXN ENP500AGT ...

Looks Good.

It has more or less everything that should be had, but reduced to its minimum and cheapest expression.

It has a MOV, but it's a tiny 10mm one that wouldn't stand many joules:

It has a PFC/PWM controller, but it's a cheap SIP format CM6805BSX intead of a standard CM6800:

It has the small 2T-forward transformer, but it looks as cheapo as they come:

It has a supervisor IC, but it's a 'half-man' ST9S313 lacking over-current protection:

(Though from the reviews apparently the thing manages to shut itself down when overloaded without exploding, perhaps from over-temp protection).

Not to mention the deal-breaking undersized Jun Fus. 😵

Looks like the CWT guy wearing belt and suspenders told to himself: 'Let's see how much deep we can dive the boat without reaching the crushing depth of fire-hazard gutless-wonder territory'. 🤣

I guess Mr. Suspenders was only responsible for the input filtering. That or he was cutting too far into the margins.

I think you're being a little over critical, here. This is far from being a gutless wonder. It does have some components sized on the small side, it does feature cheap caps, a cheap phenolic PCB, and a somewhat older design (double forward instead of LLC). This is to be expected with a budget PSU. I see no evidence of safety faults or functionality problems except for the cheap caps.

As discussed on the cap replacement thread, true gutless wonders will simply leave out filter stages and be equipped with cement PFC coils. They are unmistakeably dodgy as shit.

Yeah I just like playing devil's advocate 🤣 , in fact these budget CWT designs behave reasonably well for their tight price. Corsair uses the very similar GPM platform inside the VS450, and the slightly better DSAIII inside the CX430.

And when Mr. Suspenders is given free rein he can nail it. The Corsair RMi and RMx, which are excellent cutting edge PSUs @ 2016, are also courtesy of CWT.

A couple of extra touches, homebrew heatsinks for the GBU808 rectifier bridge and the TNY176PN standby controller (heat murders electronics):

Digged this photo out of my HDD.

It's a picture of my current PSU. It's a Fortrex ST-400W PSU,built by Allied ( though I'd lean more L&C's high end LC-B350ATX model,which TELVM also worked on,because of the EI-33 transformer (as opposed to ERL-35/LT35 that Allieds use) and the fact that while L&C used 4 diode treatment on primary,Allieds use a true rectifier.) that powers my Pentium 4 HT.

Runs hot,but it still works. It's been already recapped before I bought,one of the Rubycon caps being MHZ series. 😲

Oh,and forgot mentioning,the secondary heatsink is cut in half because this PSU has PFC.

Please locate the 5vsb critical cap and replace it immediately with GOOD brand capacitor. If this cap's esr goes high the 5vsb output voltage could skyrocket to... 12V (!) and kill your mobo.

wave wrote:

Please locate the 5vsb critical cap and replace it immediately with GOOD brand capacitor. If this cap's esr goes high the 5vsb output voltage could skyrocket to... 12V (!) and kill your mobo.

Panasonic FLs on 5vsb,both 16v 1500uF

The critical 5vsb capacitor is a small cap located in the primary section. It's usually a 22uF / 47uF 50V. Not every psu has the 2 transistor circuit that relies to that cap to function properly. This psu has 2 transistor circuit through.

Wave gives good advice, these PSUs use a two-transistor circuit for +5VSB that will fry the mobo if its related small caps go south.

The '+5VSB critical caps' he's referring to are not the two larger +5VSB output filtering caps (marked 'F'), but the smaller caps around them (marked 'C').

The two tiny caps above (marked 'D') are on the switchers driving circuit and if they fail the PSU will go FUBAR. So recapping them isn't a bad idea (though they are a royal PITA to handle 😠 , being so buried between the isolation transformer and the primary heatsink).

These PSUs are heat furnaces because efficiency is atrocious 😵 . The oversized minimum load resistors located between the secondary caps aggravate the problem. So they need overkill cooling and good 105C caps to be reliable (but most or all were built with crappy caps).

Also this PSU is probably overrated, '33' transformer and I guess '13007' main switching transistors mean ~250W tops, and fireworks above that.

These Oh Deer! PSUs had a bad reputation but once recapped and with better cooling they become reasonably passable for low-draw retrocomps, voltage regulation and ripple are acceptable.

http://ixbtlabs.com/articles2/power/rk-psu11.html
^ Scroll down to 'LC-B300ATX' and 'LC-B350ATX'

Mine, like yours in the pic, even sports PI coils for -12V and -5V. Luxury! 🤣

- EDIT:

... powers my Pentium 4 HT.

These PSUs are old-style +5V heavy and usually come with weak +12V rectifiers (mine came OEM with just a 10A superfast 😵 ), not the best recipe for +12V hungry P4s. I'd better use it to power PII/PIII or Athlon Classic stuff.

300 watt FSP powersupply got decommissioned today. Not only did three caps pop but a resistor burned up and there is no way to tell what it was originally 🙁

PcBytes wrote:

.... L&C's high end LC-B350ATX model ....

That is somewhat like saying a high end Yugo.
.

Lada... the disposable car.

TELVM wrote:

Wave gives good advice, these PSUs use a two-transistor circuit for +5VSB that will fry the mobo if its related small caps go so […]
Show full quote

Wave gives good advice, these PSUs use a two-transistor circuit for +5VSB that will fry the mobo if its related small caps go south.

The '+5VSB critical caps' he's referring to are not the two larger +5VSB output filtering caps (marked 'F'), but the smaller caps around them (marked 'C').

The two tiny caps above (marked 'D') are on the switchers driving circuit and if they fail the PSU will go FUBAR. So recapping them isn't a bad idea (though they are a royal PITA to handle 😠 , being so buried between the isolation transformer and the primary heatsink).

These PSUs are heat furnaces because efficiency is atrocious 😵 . The oversized minimum load resistors located between the secondary caps aggravate the problem. So they need overkill cooling and good 105C caps to be reliable (but most or all were built with crappy caps).

Also this PSU is probably overrated, '33' transformer and I guess '13007' main switching transistors mean ~250W tops, and fireworks above that.

These Oh Deer! PSUs had a bad reputation but once recapped and with better cooling they become reasonably passable for low-draw retrocomps, voltage regulation and ripple are acceptable.

http://ixbtlabs.com/articles2/power/rk-psu11.html
^ Scroll down to 'LC-B300ATX' and 'LC-B350ATX'

Mine, like yours in the pic, even sports PI coils for -12V and -5V. Luxury! 🤣

- EDIT:

... powers my Pentium 4 HT.

These PSUs are old-style +5V heavy and usually come with weak +12V rectifiers (mine came OEM with just a 10A superfast 😵 ), not the best recipe for +12V hungry P4s. I'd better use it to power PII/PIII or Athlon Classic stuff.

Believe it or not,it came with 13009s. Hooray. 🤣

Also,those caps are likely a decade old (Deer's 2003 design,so it's been a long time) and still are fine. I haven't had any of these PSUs go bad because of that. And as far as the 10A ultrafast,I replaced that with a 20A 60V rectifier pulled from a Linkworld long ago. This PSU used to have a Delta fan but that one died and I'm forced to use a generic "SCS cooling solutions (or something like that)" fan in it. I'd try and fit an AVC but since I rewired the fan to 12v,and the fact that both my 80 and 92mm AVC fans are helicopter grade (literally) I wouldn't do that.

Speaking of Deers though,I had the luck to find a decent one near a dumpster. It's a LC-C400ATX. Apart from the 2 FR307 (I think) diodes on a bracket,it's working absolutely fine. I presume it came from somebody's PC that upgraded stuff and threw the PSU out and so it happened to find it. It's pretty dusty,but the bright side - fan's a Jamicon! This one might have D13007 transistors,but I haven't checked. Datecodes are 2007,but they use Deer's original 05 design. (I have a LC-B450E that uses a newer version of that design,and it's 2006 built)

PCBONEZ - one of the (quite) beefy L&Cs I've seen happen to be the LC-B350ATX models,and generally half of the Allieds use the 2003 design. Newer ones I've seen (such as the 8400BTX) use the 2005 and 2006 designs.

So far, not counting the DOA ones,I've had about 7-8 Deer PSUs,from different MFGs:JNC,ANS,Premier,a noname one (with 2004 design- 2003 chip and thicker heatsinks than the first ones),Fortrex (the current one) and that's pretty much all.

PcBytes wrote:

PCBONEZ - one of the (quite) beefy L&Cs I've seen happen to be the LC-B350ATX models,and generally half of the Allieds use the 2003 design. Newer ones I've seen (such as the 8400BTX) use the 2005 and 2006 designs.

L&C and Allied are in the category of gutless wonders.
Gutless Wonder = PSU that doesn't even come close to living up to it's advertised ratings.
Calling any of them "High End" is hilarious IMO.

I occasionally get L&C or Allied in new cases.
I choose to not spend time fiddling with or rebuilding Gutless Wonders. (Or Yugos.)
I sell them on ebay for $20 shipped just to get them out of my way.
The last one was a LC-B400ATX IIRC. Maybe a 450.

If they are good for you and you like them then more power to ya. Enjoy.
A rebuilt one is probably okay if you overkill the watts ratings by enough margin.
.

PcBytes wrote:

... 13009s ... ... 20A 60V rectifier ...

^ That's better for P4s.

All things said, my Oh Deer! with its 13007s and pathetic 10A superfast somehow managed to power a friend's 3.0 Preshott system for nearly a decade without fireworks 😲 (though crappy OEM caps were oozing towards the end).