Aspire/Apevia 520W

[momaka]

Re: Aspire/Apevia 520W

I agree with c_hegge - give it a full recap and it should be a decent 300W power supply. Maybe 350W if designed right, but I wouldn't push it more, just in case.

Also, post a picture of the secondary side if possible. From the pictures at hardwaresecrets.com, it looks like there may be some big minimum load resistors on the secondary side next to the filtering capacitors. If those have too low of a resistance, they will cook your new caps as well. Therefore either post a picture or note their values and post them here. They may or may not have to be replaced depending on their values.

Usually when I see those, I replace them with a 47 Ohm 1W for the 3.3v rail, 100 Ohm 1W for the 5v rail, and 470 Ohm 1W for the 12v rail.

[c_hegge]

Re: Aspire/Apevia 520W

I'd recap it, but make sure you replace all of the really small caps without vent stamps, so you get that "killer cap" on the 5vsb. It may not be a 520W, but with good caps, I would say it would be OK as a 250-300 Watter. It does actually have a good input filter and transformer.

[Trinite]

Re: Aspire/Apevia 520W

Any suggestions on what to do with this PSU? Worth recapping and selling? Or better as a paperweight?

[Trinite]

Re: Aspire/Apevia 520W

Yeah, I've been examining the circuitry. The 5VSB looks really sketchy. It seems the C5353 feeds back into a C2235, which in turn feeds back into the C5353 - viola! Self-oscillation! And the whole thing is regulated, like you said, by a 431 via optocoupler.

As for caps, looks like the 3.3V rail uses two 10V 3300uF, the 5V uses one 16V 3300uF and one 10V 470uf, the 12V uses one 16V 3300uf and one 16V 470uf, the -5V uses one 10V 470uF, the -12V uses one 16V 470uF and lastly, the 5VSB uses one 10V 1000uF and one 10V 2200uF.

I thought at first that both 16V 3300uF capacitors were for the 12V, but looks like they really decided to skimp on this.

[momaka]

Re: Aspire/Apevia 520W

There's two types of self-oscillating 5vsb designs - one is with feedback (the 2-transistor design) and the other is without (seen in older L&Cs and Deers, uses 7805 regulator for 5vsb).
Neither of these designs use a PWM controller.

Your 5vsb uses a 2-transistor self-oscillating circuit - it has no ICs other than an optocoupler and a 431 shunt regulator (found on the secondary side, usually looks like a transistor in a TO-92 case).

KA7500 is the PWM controller for the main supply and AAT1014 likely handles the protections (short circuit, OVP, and UVP).

By the way, how many caps are there for each rail and what's their value?

[Trinite]

Re: Aspire/Apevia 520W

I'm quite sure it is a two transistor 5vsb design. If there's no TopSwitch, Viper or the like IC, it's a self-oscillating circuit. Anyway. Check for a zener on the 5vsb line. If it is there, no need to worry about. If it isn't, drop in a 5v1, 1W zener. That will save your motherboard if the self-oscillating wonder decides it's time to bump up the voltage. It will make a hole in the 5vsb transistor though.

Self-oscillating, you say? Sounds delightfully unstable. I don't see any zeners present, so I'll have to install one.

It does use a KA7500C, which provides a 5V reference supply, but I don't know if that is for the chip itself, or whether it actually regulates the 5VSB. The voltage monitoring chip is an AAT1014, but I don't think it's relevant to the 5VSB, unless it uses it for VCC.

[Th3_uN1Qu3]

Re: Aspire/Apevia 520W

I'm quite sure it is a two transistor 5vsb design. If there's no TopSwitch, Viper or the like IC, it's a self-oscillating circuit. Anyway. Check for a zener on the 5vsb line. If it is there, no need to worry about. If it isn't, drop in a 5v1, 1W zener. That will save your motherboard if the self-oscillating wonder decides it's time to bump up the voltage. It will make a hole in the 5vsb transistor though.

[Trinite]

Re: Aspire/Apevia 520W

That's what ALL of them use. Well, sometimes a N-Mosfet, but it's still a N. The two transistor circuit is located lower down the line.

This unit is so overcrowded with components and wires (terrible layout), it's hard to tell what's in here without desoldering stuff. I did find two transistors after the 5VSB transformer, one of which is a 2SC2235. The other one is identical, but the numbering is obscured, but I assume it is the same (or complimented with a 2SA965). Not sure if this is the aforementioned 5VSB of doom or not

Also, I actually do have a PSU lying around somewhere that came with a computer case that uses a couple TO-92 type transistors to switch the 5VSB, instead of a TO-126/TO-220 type transistor. I'll have to see if I can find it and post some pics of its shameful guts (or lack thereof). Edit: It could also have been a single-transistor forward design, and the other transistor would have served the 5VSB, as there were only 2 transistors on the heatsink. I'll have to see.

[Th3_uN1Qu3]

Re: Aspire/Apevia 520W

The 5VSB seems to use a single NPN transistor attached to its own heatsink.

That's what ALL of them use. Well, sometimes a N-Mosfet, but it's still a N. The two transistor circuit is located lower down the line.

[momaka]

Re: Aspire/Apevia 520W

I don't see too many capacitors on the secondary side. Secondary torroids look small too. Good luck with the noise and ripple suppression after 200 Watts.

I have a "580W" EchoStar that has bigger heatsinks than that.

Echo Star?
... I can only think of this thread:
https://www.badcaps.net/forum/showth...ight=echo+star

[Trinite]

Re: Aspire/Apevia 520W

ouch... sounds like you have the 2 transistor 5vsb of doom. strike one.

what brand fan is in it and are you using it? do you know how well it runs? half the problem often is poor fans.

the heatsinks look a bit tiny... and are the output wires of a good gauge?

tread with caution... I would be careful with it...

The 5VSB seems to use a single NPN transistor attached to its own heatsink. Appears a bit more robust than using the 2 transistor setup (I assume you're talking about the 2 undersized transistors you see on the 5VSB in most cheapo PSUs). The fans are Aspire (Apevia) brand, seem to run fine. The wiring is 18AWG.

incorrect circuit analysis, I thought.
two SBL3040PT are used for 3.3V and 5V line, MBR30100CT is used for 12V line.

Oops, looks like I did get the transformer taps backwards


And Th3_uN1Qu3, I guess it would true about the output. Even if the diodes are kept sufficiently cool, there would likely be too much voltage drop across the diode to maintain ATX spec for 12V at a 34A load.

[b700029]

Re: Aspire/Apevia 520W

30*12 + 30*5 + 30*3.3 = 609W on the secondary, and with an efficiency of 70% that means the primary is drawing 870W which should still be within limits. The ERL42 transformer looks sufficient, but the heatsinks need to be much bigger. I have a "580W" EchoStar that has bigger heatsinks than that.

[POM_MJ]

Re: Aspire/Apevia 520W

...
On the secondary side, it has the following: A SBL3040PT Schottky rectifier for the 12V line, rated for 30A @ 100°C. This gives 360W, a bit shy of the 34A/408W rating for the 12V line. Assuming the unit is rated at 25°C as most cheap PSUs are, this would allow for that rating to be in spec, since diodes can handle more current at lower temperatures (just don't stick it in a really hot case). The 5V line also uses a SBL3040PT rectifier, so it too is limited to 30A. The unit is rated for 29A on the 5V rail, so this is within the limit. The 3.3V line is on a MBR30100PT rectifier, also rated at 30A. The 3.3V rail is specified at 30A, so this is right at the limit.
...

incorrect circuit analysis, I thought.
two SBL3040PT are used for 3.3V and 5V line, MBR30100CT is used for 12V line.

[Scenic]

Re: Aspire/Apevia 520W

hmm.. i think i've just found out who manufactured the cheapo junker "Xilence" 500W PSU i pulled from a customer box (quadcore with a relatively high end video card.. i bet you can guess what the problem was)

i remember those blue transformers and all-yellow caps.. looks so odd.. which is probably why i remember it lol

[370forlife]

Re: Aspire/Apevia 520W

I don't know where gabe got his information from, but sun pro and youngyear are two different companies, each their own OEM.

[Th3_uN1Qu3]

Re: Aspire/Apevia 520W

To my surprise, it seems to be a much better build than most Young Year (OEM Sun Pro) makes.

I have a 350 watter here that i have to put all the cables on (bought it as bare board along with 11 others ), it uses all Fuhjyyu SkR caps in the secondary *gasp* 85C!!! However the caps have generous can sizes and all tested good.

Apart from the improperly chosen 12v feedback point which i moved and added pi filter, the build quality is very, very good. PCB layout is super clean, and there's quite a number of SMDs on the back side. I believe i've posted it here a while back.

It has a complete transient filter (2 X/2 Y capacitors, 3 filter coils, 1 NTC thermistor and an MOV).

Same here.

The two switchers are NPN C5071, rated for 24A pulse / 12A continuous. Since it is in switch mode, the 24A rating is what we use.

You forgot to read the fine print - the 12A continuous value is given at 25C, and the pulse test is at an obscenely low duty cycle (read: short pulse long pause). Totally unrealistic for SMPS conditions. The continuous rating is what you're interested in. An educated guess would be 8-9A at 75C. Still enough.

A SBL3040PT Schottky rectifier for the 12V line, rated for 30A @ 100°C. This gives 360W, a bit shy of the 34A/408W rating for the 12V line. Assuming the unit is rated at 25°C as most cheap PSUs are, this would allow for that rating to be in spec, since diodes can handle more current at lower temperatures.

Yes and no. Diodes can handle A TON of current provided Tjunction is not exceeded (i pushed 10A thru a 3A diode from a power supply with "diodes-on-a-bracket", and it still lives to tell the tale), but voltage drop actually decreases as Tjunction gets higher, so higher efficiencies are obtained at higher temperatures. It's the other way round with switching transistors though.

All in all, it seems a decent power supply for the budget range. Would it hit its 520W rating? Probably not. I don't have the equipment to test it, but I'm assuming it could manage around 480W or so.

I wouldn't call it "decent" but it'll work in a pinch. It will also likely hit its 520W rating... for 1 second or so. 400W is more realistic of it.

[Th3_uN1Qu3]

Re: Aspire/Apevia 520W

To my surprise, it seems to be a much better build than most Young Year (OEM Sun Pro) makes.

I have a 350 watter here that i have to put all the cables on (bought it as bare board along with 11 others ), it uses all Fuhjyyu SkR caps in the secondary *gasp* 85C!!! However the caps have generous can sizes and all tested good.

Apart from the improperly chosen 12v feedback point which i moved and added pi filter, the build quality is very, very good. PCB layout is super clean, and there's quite a number of SMDs on the back side. I believe i've posted it here a while back.

It has a complete transient filter (2 X/2 Y capacitors, 3 filter coils, 1 NTC thermistor and an MOV).

Same here.

The two switchers are NPN C5071, rated for 24A pulse / 12A continuous. Since it is in switch mode, the 24A rating is what we use.

You forgot to read the fine print - the 12A continuous value is given at 25C, and the pulse test is at an obscenely low duty cycle (read: short pulse long pause). Totally unrealistic for SMPS conditions. The continuous rating is what you're interested in. An educated guess would be 8-9A at 75C. Still enough.

A SBL3040PT Schottky rectifier for the 12V line, rated for 30A @ 100°C. This gives 360W, a bit shy of the 34A/408W rating for the 12V line. Assuming the unit is rated at 25°C as most cheap PSUs are, this would allow for that rating to be in spec, since diodes can handle more current at lower temperatures.

Yes and no. Diodes can handle A TON of current provided Tjunction is not exceeded (i pushed 10A thru a 3A diode from a power supply with "diodes-on-a-bracket", and it still lives to tell the tale), but voltage drop actually decreases as Tjunction gets higher, so higher efficiencies are obtained at higher temperatures. It's the other way round with switching transistors though.

All in all, it seems a decent power supply for the budget range. Would it hit its 520W rating? Probably not. I don't have the equipment to test it, but I'm assuming it could manage around 480W or so.

I wouldn't call it "decent" but it'll work in a pinch. It will also likely hit its 520W rating... for 1 second or so.

[ratdude747]

Re: Aspire/Apevia 520W

ouch... sounds like you have the 2 transistor 5vsb of doom. strike one.

what brand fan is in it and are you using it? do you know how well it runs? half the problem often is poor fans.

the heatsinks look a bit tiny... and are the output wires of a good gauge?

tread with caution... I would be careful with it...

[Trinite]

Yes, one of these...

I pulled this one out of a computer and opened it up to find it filled with bloaters. Still working when I removed it, oddly enough.

To my surprise, it seems to be a much better build than most Young Year (OEM Sun Pro) makes.
(Hardware Secrets article here)

It has a complete transient filter (2 X/2 Y capacitors, 3 filter coils, 1 NTC thermistor and an MOV). The rectifying bridge is a PBU805, rated 8 amps at 100°C. At 120V, this gives a limit of 960W, well within spec. The two switchers are NPN C5071, rated for 24A pulse / 12A continuous. Since it is in switch mode, the 24A rating is what we use. This also appears to be sufficient for the 520W rating of the unit. The transformer seems to be of sufficient size as well. The 5VSB is provided by a C5353 transistor, rated at 5A pulse / 3A continuous. This meets the rating of the 5VSB rail, which is at 2A.

On the secondary side, it has the following: A SBL3040PT Schottky rectifier for the 12V line, rated for 30A @ 100°C. This gives 360W, a bit shy of the 34A/408W rating for the 12V line. Assuming the unit is rated at 25°C as most cheap PSUs are, this would allow for that rating to be in spec, since diodes can handle more current at lower temperatures (just don't stick it in a really hot case). The 5V line also uses a SBL3040PT rectifier, so it too is limited to 30A. The unit is rated for 29A on the 5V rail, so this is within the limit. The 3.3V line is on a MBR30100PT rectifier, also rated at 30A. The 3.3V rail is specified at 30A, so this is right at the limit.

All in all, it seems a decent power supply for the budget range. Would it hit its 520W rating? Probably not. I don't have the equipment to test it, but I'm assuming it could manage around 480W or so.

Of course, the Achilles heel of this unit is the bad caps they used (mostly YC in this case). Should do much better once I get this recap finished.