The KING

[everell]

Here is the KING, and I don't mean Elvis Presley! First thing to notice is that the brand sticker has been replaced. Residue from the old sticker is still present. I have no idea who the OEM is. This is a half bridge design. The fan was stuck. Every capacitor in the output circuits was bulging. So I replaced them all with some pullouts from my collection, increasing values a little. The main input capacitors were 330 uF/200 volts and were replaced with pull out 470 uF/200 volts. It did have pi output filters on the 5 volt rail and 3.3 volt rail. Single capacitor 1000 uF/16 volts on the 12 volt rail which I increased to 2200 uF/16 volts. The TO-220 output diodes on the 3.3 volt rail and 5 volt rail were replaced with shottky 30 amp 45 volt pullouts. The F12C20 output diode on the 12 volt rail was replaced with F16C20.

On initial test, only a fan twitch. Found that the output diode on the 5 volt rail had one side shorted. That is why I "improved" the output diode arrangement.

Second test with no load, the power supply came up running fine.

For third test, I removed my I-Micro 400 watt power supply from my Pentium 3 test board (the I-Micro that blew up when tested with a Pentium 4 board). I installed the KING and powered up. NOTHING - just a black screen on the monitor. At least the CPU fan and power supply fans were running. A real disappointment considering that the I-Micro would at least power a Pentium 3 board.

Here are some pictures of the KING with all repairs made.

[Wester547]

Re: The KING

Any chance some of the tiny JEEs are bad? Unless those didn't come with the unit. If the one driving the BJTs go, bad they can increase the switching losses of the BJTs, for one thing.

[LDSisHere]

Re: The KING

For a cheap power supply I am surprised by the populated input protection, ceramic fuse and the use of headers for the power and fans.

Did you check your voltages when powering the P3 board? Could it just be one rail sagging under load that affects the video chip set?

[mockingbird]

Re: The KING

That looks maybe like a very old FSP design.

[kaboom]

Re: The KING

For third test, I removed my I-Micro 400 watt power supply from my Pentium 3 test board (the I-Micro that blew up when tested with a Pentium 4 board). I installed the KING and powered up. NOTHING - just a black screen on the monitor. At least the CPU fan and power supply fans were running. A real disappointment considering that the I-Micro would at least power a Pentium 3 board.

I bet PG is staying low, keeping the mobo in reset. Change those small caps near the '494 and power good ckt (near those transistors and gray wire).

Also change any non-Jap caps on the secondary outputs.

[everell]

Re: The KING

That looks maybe like a very old FSP design.

I don't know if it is FSP, but it is a very old design. Supervisory circuitry is all transistors, not the usual 339 integrated circuit. Date on the QC sticker is April 2003.

[everell]

Re: The KING

I bet PG is staying low, keeping the mobo in reset. Change those small caps near the '494 and power good ckt (near those transistors and gray wire).

Also change any non-Jap caps on the secondary outputs.

You are correct......PG out is staying low. Looks like I have a lot of small capacitors to replace. This was supposed to be a KING, not a nuisance.

[kaboom]

Re: The KING

You are correct......PG out is staying low. Looks like I have a lot of small capacitors to replace. This was supposed to be a KING, not a nuisance.

Hey, at least it's not thecapking!!!

[Dan81]

Re: The KING

Actually,it's not a old FSP.

The OEM's Sun Pro. I don't know how you all didn't notice the KY-400ATX model number,specific for Sun Pro PSUs. Also the logo is very similar to Sun Pro's logo.

[momaka]

Re: The KING

Actually,it's not a old FSP.

The OEM's Sun Pro. I don't know how you all didn't notice the KY-400ATX model number,specific for Sun Pro PSUs. Also the logo is very similar to Sun Pro's logo.

Correct!

Not only that, but the UL number, E210743, also matches what I have for a Sun-Pro built RaidMax RX-380K PSU.

Actually, here's a post I made on mine:
https://www.badcaps.net/forum/showpo...&postcount=883
Notice how similar the PCB designs are. Except yours has much more "beefier" parts and a mag-amp circuit for the 3.3V rail, whereas mine has a MOSFET and 3.3V rail is linearly regulated.

I deem that to be one of the worst PSUs I have (or maybe a close second after my JNC LC-235ATX). If you put better heatsinks in yours, it might be somewhat more use-able. The output toroid inductor actually looks of decent size. I guess this is as good and complete as this model gets. Like LDSisHere, I too am surprised to see connectors and a ceramic fuse. It's almost an OK PSU, actually ... well, almost .

[Agent24]

Re: The KING

King Yes? It should be called King No....

Must be some fault in the power good circuit, might not even be capacitors.

[everell]

Re: The KING

Actually,it's not a old FSP.

The OEM's Sun Pro. I don't know how you all didn't notice the KY-400ATX model number,specific for Sun Pro PSUs. Also the logo is very similar to Sun Pro's logo.

Model KY-400ATX.........does that mean this is supposed to be a 400 watt power supply.........sorta like the IMicro 400 watt power supplies?????

[kaboom]

Re: The KING

Model KY-400ATX.........does that mean this is supposed to be a 400 watt power supply.........sorta like the IMicro 400 watt power supplies?????

Only on the sticker...

I'd say 150-175W with those stupid "T" heatsinks. Look at how little cross section there is behind/above the devices- how can that possibly conduct the heat well to the "top hat" where the holes are?

[momaka]

Re: The KING

I'd say 150-175W with those stupid "T" heatsinks. Look at how little cross section there is behind/above the devices- how can that possibly conduct the heat well to the "top hat" where the holes are?

Ah, but you see, diodes and rectifiers have a lower Vf at higher temperatures . Thus the PSU achieves higher efficiency .

On that note, all I have to say is, the Raidmax RX-380K that I pointed to in my above post was still very inefficient. It was used in a family friend's PC that drew maybe only 100W at the most (s462 AMD Athlon XP 2000+, GeForce FX5200, and one or two HDDs). This PSU always ran very hot and blew a lot of hot air, despite its fan being wired straight to 12V. So yeah, even with hot rectifiers, it was still miserably inefficient. You can see how "well-done" the PCB looks on my unit.

Everell, I sure hope the efficiency of your's isn't as terrible as that.

[Agent24]

Re: The KING

Ah, but you see, diodes and rectifiers have a lower Vf at higher temperatures . Thus the PSU achieves higher efficiency

[everell]

Re: The KING

kaboom, you are correct. I replaced eight small JEE capacitors in the area you indicated. The PG_out signal is now good. The KING will now power my Pentium 3 test motherboard just as good as the IMicro.

[Dan81]

Re: The KING

kaboom, you are correct. I replaced eight small JEE capacitors in the area you indicated. The PG_out signal is now good. The KING will now power my Pentium 3 test motherboard just as good as the IMicro.

I'd be against trying it with a Pentium 4,considering how one of your IMicros (I see you had/have 3 of them) went off with a bang on a Pentium 4:

With boldness, I attached it to a Pentium 4 class motherboard. Pushed PS_on switch.....BANG, fizz, and a small fireball! Both switching transistors shorted, the C945 driver transistors were bad, and the 7500 pwm chip was shorted. Also a couple of bad diodes, and the resistors in one of the switchers had blown resistors. I replaced the switching transistors with 13007. I also replaced the two electrolytic capacitors in the switching transistor circuits. Replaced the driver transformer just in case it shorted. Attached it to the Pentium 3 motherboard and once again it came to life.

I still remember how my Sun Pro built Delux died...

[momaka]

Re: The KING

kaboom, you are correct. I replaced eight small JEE capacitors in the area you indicated. The PG_out signal is now good. The KING will now power my Pentium 3 test motherboard just as good as the IMicro.

Wow, for that circuit not to work, that means those JEE caps really must have gone high ESR. I guess JEE really is that terrible .

I still remember how my Sun Pro built Delux died...

Was it something along the lines of...

Press power button...
Everything seems to be working?

OK, time to do some computing!
Then, all of a sudden...

[Dan81]

Re: The KING

Was it something along the lines of...

Press power button...
Everything seems to be working?

OK, time to do some computing!
Then, all of a sudden...

Nope. I was recapping it,then I assembled it together,and as soon as I flipped the power switch on it,it started fizzing and popping,and then it died.

[everell]

Re: The KING

Was it powering a Pentium 3 or Pentium 4 type motherboard?