Fixed Topower TOP-350W801

[Pentium4]

I got this thing with a destroyed fan (The plastic holding the shaft to the blades broke) and the thing had no power, not even 5VSB. I pulled it to inspect it. Fuse wasn't blown, strange....
I looked at the soldering side, which was of horrible quality. I found a broken joint on the PFC coil, and a cold joint on the startup resistor. Plugged it in, still nothing....

Checked bridge rectifier, PFC silicon, all diodes/resistors on the primary, and then noticed the cracked PFC film cap. Replaced that with a better spec'd part. Still nothing. I pull it and throw it into another PSU chassis, and it fired right up! I figured it must have been some of the input filtering components on the small PCB before the fuse, so I took a similar one off another PSU and threw it back in the original chassis. No power, not even 5VSB.......WTF!! So then I pulled the AC plug and found that the glue had hardened on one of the AC pins. Wow! I guess it just shows not to over-think things, which I tend to do too often.

I recapped it because all the caps were Ejicon (They all tested good), upgraded the bridge rectifier from 4A to 6A, mainly because the BR, PFC film cap, and fusible resistor were all packed in there too tight. Installing the bridge rectifier moved over to the side like that gave the other two components room to breathe, and at least they're not touching each other anymore.

I find it interesting at their choice of heatsink sizes. Biggest on the PFC silicon??? I also could not believe that they didn't put a plastic sheet between the toroid coils and output rectifiers! I installed one.

[kaboom]

Re: Fixed Topower TOP-350W801

You know, this almost happened to me, with an AT clone system years ago.

I got lucky- there was so much glue-goo, the plug would no longer fit onto the header, making the problem obvious.

Wonder how hot that PFC booster gets at full load... that heatsink looks like they're disaster planning. I know, I know, "punny."

[momaka]

Re: Fixed Topower TOP-350W801

Wow! Another QC Passed PSU.

I'm surprised the bad connection on the AC connector didn't cause any burning/heating. I wonder how many of the cheap PSU reviews on newegg and other websites that mention DOA had this problem.

As for the PFC heatsink... I thought APFC was all about improving efficinecy (not really).
Pentium4, you should get one of those $5 type-K thermometers. Then you can measure heatsink temperatures easily.

The PSU does look nice with the blue fan, though. Good save. I think it looks overall capable of handling a low-end system. Maybe even handle something mid-end too. Is it a single-transistor forward? And what are the rectifiers on the secondary?

[Behemot]

Re: Fixed Topower TOP-350W801

Well, not always. When the heatsink us live, it will measure nonsense.

But having the biggest heatsink in PFC section is quite normal these days. Modern topologies with good silicon improved efficiency greatly so switchers and rectifiers usually have only small heatsinks. But boost PFC have not changed a bit. Wonder what the efficiency would be without PFC with 230 V AC - 95+ %?

[Pentium4]

Re: Fixed Topower TOP-350W801

Yeah I need to buy a type K thermometer. That would come in handy. I'll see about ordering one some time this week

that heatsink looks like they're disaster planning. I know, I know, "punny."

Planned obsolescence? They wouldn't dare!

And Behemot, you're right. Silicon is semi beefy for a 350 watter. PFC transistor is 24A, PFC diode is 10A. Switchers are 14A FETs. 5V and 3.3V has 30A. 12V rail is actually dual rail, with 20A schottky each. It does indeed look good with the blue fan That's actually from the ePower I'm still working on. Branded H.X.S.

[c_hegge]

Re: Fixed Topower TOP-350W801

So the broken fan was the SuperFan? Where's the Kryptonite?

[stj]

Re: Fixed Topower TOP-350W801

Yeah I need to buy a type K thermometer. That would come in handy. I'll see about ordering one some time this week

given he voltages, you would be safer getting a non-contact IR thermometer.
the chinese do them for about $25

[Pentium4]

Re: Fixed Topower TOP-350W801

So the broken fan was the SuperFan? Where's the Kryptonite?

the chinese do them for about $25

But do they work?

[stj]

Re: Fixed Topower TOP-350W801

yes, they are very simple things.
Fluke & friends have made like bandits for the last few years charging 200+ for them - those times are over.

[Pentium4]

Re: Fixed Topower TOP-350W801

Cool, do you have a model that you recommend?

[stj]

Re: Fixed Topower TOP-350W801

no, just trawl ebay for a good price.

they are basicly a pyro sensor not so different to the ones used in PIR security lamps afaik.
the output is proportional to IR energy infront of the sensor and it feeds to a display that converts the voltage into a temp reading.

one thing i do know about these things, dont use them outdoors on shiny stuff, they will pick up the sun!

[budm]

Re: Fixed Topower TOP-350W801

I got this from HF on sale for $19, the readout is within a couple degree to the Fluke I use in the lab. Sears also sells the same version at higher price.
https://www.badcaps.net/forum/attach...0&d=1357462883

[stj]

Re: Fixed Topower TOP-350W801

$19 retail? damn that's cheap!

[Behemot]

Re: Fixed Topower TOP-350W801

Would not recommend infrathermometer, this can reach error in terms of hundred % depending on surface properties. It is designed according to black-body radiation.

[budm]

Re: Fixed Topower TOP-350W801

[Behemot]

Re: Fixed Topower TOP-350W801

Oh man messing with some emissivity dren when you can just use good ol' contact thermometer, just electrically insulated…

[momaka]

Re: Fixed Topower TOP-350W801

Would not recommend infrathermometer, this can reach error in terms of hundred % depending on surface properties. It is designed according to black-body radiation.

+1
The object size and distance from which you measure it also influence the temperature quite a bit.

This is why I recommend the type-K thermometers (and never looked back to infrared thermometers). As a bonus, the type-K can be handy if you want to experiment with BGA reflowing.

The one I usually reccomned is TM-902C. If you don't mind the slow boat from China/Hong Kong, it can be found for around $5. Like these:
http://www.ebay.com/itm/Top-TM902C-D...item1e9620eda2
http://www.ebay.com/itm/TM-902C-Digi...item19f52c0441
They come with everything you need - even a battery (it's a no-name carbon-zinc batt. but it serves the purpose... I got mine two years ago and the battery is still fine).

given he voltages, you would be safer getting a non-contact IR thermometer.

It is fairly safe to use that meter to measure electrically-hot heatsinks. Obviously just don't touch the probe or any metal parts on the meter once the probe is in contact with a high voltage uninsulated device. And be careful that the probe wires don't touch anything else metal. Reason why is because the probe wires are insulated, but it a thin low-voltage insulation.

[Behemot]

Re: Fixed Topower TOP-350W801

If you are OK with up to 110 °C, I have run across http://www.ebay.com/itm/301497403612 or similar. This one in particular has molex for power and displays also with 0.1 acurracy.