Power supply build quality pictorial. part 2

[lti]

Re: Power supply build quality pictorial. part 2

At least they used separate labels for each model. When the label has output ratings for every model that company sells, you know it's junk.

Even my 75W Hipro I posted earlier has a rectifier in a TO-247 package.

[inVain]

Re: Power supply build quality pictorial. part 2

hello, this is my first post on this forum
this is my TX650 when I replacing the fan with a Delta WFB











everything is so thight, I can barely see anything
but all caps are nichicon

thing that bothers me is when I monitored the Delta with my mobo sensor,
it only spinning around 700 rpm (it's rated for 2500rpm)...
so anyway, should I be woried by this?

thx in advance

[c_hegge]

Re: Power supply build quality pictorial. part 2

There's not a nichicon cap in sight there. They are Nippon Chemi-con.

The fan spins slower because the power supply temperature controls it (ie. It gives it a lower voltage when it is cool).

[inVain]

Re: Power supply build quality pictorial. part 2

ah my bad....
thx for the quick reply

[SIDMX]

Re: Power supply build quality pictorial. part 2

No Brand - LPM2-20 PSU

I think this PSU is a strong contender for the Hall of Shame/gutless, it's "rated" at 300W no brand on it, Primary caps are 470uf/220V
all caps are HEC brand,no input or EMI filter, unapproved y caps, there is a thermistor but it is a tiny one like 9mm or so (not shown in pics)
Four diode treatment, well at least all are rated @ 2A however i don't see any use of it as it uses the smallest main transformer that i have seen
in a PSU, only 2 shottky rectifiers.

I don't know what kind of solder they used for but i know for sure that the silicone over the output caps is stronger than the solder because
i was trying to remove the silicone by softly pulling it and the cap came out along with the silicone anyway that cap (10x20mm) was used
to show size comparison with the main transofmer in the pics.

Speaking of output caps there are only 5, all of them are 1000uf (except one 470uf for -12V), one for each output except +5v wich got two.This unit does not use an isolation transformer instead use optocouplers... don't know if this is bad or good i think is bad as i haven't seen any modern PSU using optos instead of transformers also i don't understand why is that Mosfet in the secondary heatsink (40N03P)...may be someone can clarify this

Back to the design this crap actually have a -5V output, that and the fact that the design is more inclined towards +5V tells me that this thing was made with old hadware in mind ... or maybe just was made by some uhmm... idiots.

I didn't take out the pcb to be sure but i think the 6A shottky must be responsible for +12V and the 30A for +3.3V/+5V.

I'm still learning in PSU area, so i'm sure you will find some more fails in the design and/or component's quality so bring it on...

[Th3_uN1Qu3]

Re: Power supply build quality pictorial. part 2

No Brand - LPM2-20 PSU

That's a Linkworld. Also known as Stinkworld from the smell they produce when they die.

This unit does not use an isolation transformer instead use optocouplers... don't know if this is bad or good i think is bad as i haven't seen any modern PSU using optos instead of transformers

Nah, it's just a different way to control things. This PSU has the controller on the primary side driving the switching transistor directly, so there's no need for a driver/isolation transformer, and to isolate the feedback loop between secondary and primary they use an opto on the main supply as well. All PSUs use an opto in the standby supply.

also i don't understand why is that Mosfet in the secondary heatsink (40N03P)...may be someone can clarify this

As you have noted there are only two double diodes in the secondary. What that MOSFET does is generate 3.3v from 5v.

Back to the design this crap actually have a -5V output, that and the fact that the design is more inclined towards +5V tells me that this thing was made with old hadware in mind ... or maybe just was made by some uhmm... idiots.

Most cheap PSUs are using outdated designs and this is no exception. It might've cut it in the PIII/Athlon days, but in a modern PC... no way.

[Agent24]

Re: Power supply build quality pictorial. part 2

I don't know what kind of solder they used for but i know for sure that the silicone over the output caps is stronger than the solder because
i was trying to remove the silicone by softly pulling it and the cap came out along with the silicone

Probably conductive glue instead of solder

Actually more likely a disturbed solder joint in manufacture, in fact that capacitor probably never did any filtering since it was probably never connected into the circuit properly.

[SIDMX]

Re: Power supply build quality pictorial. part 2

@ Th3_uN1Qu3:
Thanks for the reply now it makes sense, i'm not used to this kind of designs as almost all PSUs that i have opened were using newer designs than this one.

@Agent24:
I think you're right, instants after the cap came out i just can lol saying: "oh my...you idiots that is suposed to be backwards, the solder goes in the bottom and the silicone in the top" crappy manufacturing indeed


Now i have a surprise for you all (at least it was for me) ...this PSU isn't dead and it was powering a dual core celeron with 2GB ram, a 7200GS vga, an old 80gb IDE HD (dead now, that's the reason the owner came to me) and an ECS mobo, he says that this pc was a PIII then he took it to a guy who then upgraded all the parts but insisted that the psu was enough for the new parts and that was like almost 2 years ago

i think is either a LIE or PURE LUCK ...anyway i put a new PSU already in it.

[c_hegge]

Re: Power supply build quality pictorial. part 2

The fan actually blows in

[ratdude747]

Re: Power supply build quality pictorial. part 2

The fan actually blows in

maybe they figured anybody dumb enough to buy one must be smoking something , so perhaps that would keep out the sidestream smoke near the front?

[b700029]

Re: Power supply build quality pictorial. part 2

Now i have a surprise for you all (at least it was for me) ...this PSU isn't dead and it was powering a dual core celeron with 2GB ram, a 7200GS vga, an old 80gb IDE HD (dead now, that's the reason the owner came to me) and an ECS mobo, he says that this pc was a PIII then he took it to a guy who then upgraded all the parts but insisted that the psu was enough for the new parts and that was like almost 2 years ago

i think is either a LIE or PURE LUCK ...anyway i put a new PSU already in it.

A PIII takes <50W at full load, and a 7300GS around 16W (also full load). Add another 20W for everything else (chipset, hard drive, etc.) and it's still less than 100W, which that wimpy PSU is capable of. Consider that most users never run their system at full load for any appreciable amount of time if at all, and it's not surprising. A dualcore Celeron is a little higher at 65W, but once again that is at full load with idle power consumption being significantly less.

[370forlife]

Re: Power supply build quality pictorial. part 2

It looks like it's a single transistor forward. They almost never use an isolation transformer to drive the transistor, usually only half bridge units use that.

[goodpsusearch]

Pro-V Power 250W (MPT-A250W)

This is probably a Macron Power OEM.

Missing input filter:
No Y caps
No X caps
Fake input coil
No MOVs
Tiny thermistor

Primary side:
4 tiny diodes in the place of a bridge rectifier
2x220uF input Caps ....
small transformer and switching transistors

Secondary side:
2 normal diodes for 12V ...
1x cap for every volt output
etc

The label says "Noise Killer" but it should be named "killer noise" as the fan runs all the time at 12V.

I didn't expect this from Macron Power.

[mariushm]

Re: Power supply build quality pictorial. part 2

Technically this is a "power supply" ... barely.

small intro: we have these small stores here that sell all kind of crap for a fixed value, I guess kind of like the 1$ stores in US.
Only here, somehow these people often bribe customs agents or manage to get stuff that's confiscated by the customs to be destroyed because they're dangerous or not following the European safety standard.

Well, my mother went in to buy some coat hangers and other various stuff and found this and thought I'd need it, because she knows I play with electronics. Can't blame her - it was a nice gesture.

But let's open it... a classic wall wart or whatever it's called.
First of all the cable actually goes inside though a hole that seems like it's cut with an knife...
There's only one diode which I guess rectifies the AC voltage and what seems to be a transistor (nothing written on it) but I'm not sure what's it used for - probably for the led?
You can see the wires coming from the transformer are soldered to just a few of the selections - 3v, 7.5v and 9v isn't even connected and 7.5v pad is actually gone from the board. Actually, if you look in the back you can see the switches are soldered in pairs so it's not by accident.

The capacitor in the corner is 1000uF 10 V - god knows if the cap gets 12v on it - i'm not keen to even plug this thing into the socket.

[lti]

Re: Power supply build quality pictorial. part 2

It looks like typical dollar store crap.
Just make sure you get the polarily correct.

[Scenic]

Re: Power supply build quality pictorial. part 2

how cute.. (and dangerous Oo)

Reminded me of my universal wallwart that i bought when i was 9 or 10 (I'm 24 now).
Except mine does what the label says and i't considerably more beefy than that black blob of plastic and metal that wants to be a PSU in your pics lol

AAA battery for size comparison.
There's a SEC (Samsung) LM317T on that heatsink (capable of 1.5A, so the PSU is underrated by 500mA)
the whole thing weighs about 550g

As you can see, i still got it and it still works fine after 14+ years of torture
(it has been ridiculously overloaded before for longer periods.. i was young and didn't know much or didn't care :P)

[Agent24]

Re: Power supply build quality pictorial. part 2

They both say 1 Amp but the el-cheapo one has a transformer about 3 times thinner!

Love to know what that weird black round thing is on it too.

Good for parts, maybe. Or just laughing at.

[ben7]

Re: Power supply build quality pictorial. part 2

Scenic:
Haha, thats a good looking supply!, although it could use a bigger heatsink on the regulator.

mariushm:
That transformer looks handmade, it doesn't appear to be varnished at all!

I have seen a few crappy wall warts give up the ghost, the scariest one had its primary overheat, it started crackling, and white smoke started drifting out of its vents. I also took apart another that had a similar fault. One also melted its casing, probably from another overheated primary.

Many of them dont even have [thermal] fuses on the primary!
(though the primary is thin and just acts like a fuse)

I have an "anondia" brand capacitor from a wall wart that is old looking, but still working well. Just wondering if anyone has heard of that brand.

Infact, i could go to the surplus store and get a whole bag of phone chargers for a few bucks, would be interesting to dissect them.

The Best phone charger I have seen was an old nokia charger, it had an Astec power supply, with Lelon and Nichicon caps in it, a nicely sized transistor, a control chip, secondary feedback, and even a mini bridge rectifier on the input!

-Ben

[Scenic]

Re: Power supply build quality pictorial. part 2

Love to know what that weird black round thing is on it too.

looks like an unlabelled bridge rectifier

[ben7]

Re: Power supply build quality pictorial. part 2

They both say 1 Amp but the el-cheapo one has a transformer about 3 times thinner!

Love to know what that weird black round thing is on it too.

Good for parts, maybe. Or just laughing at.

Oh silly, the black round thing is a bridge rectifier

-Ben