Konig CMP-PSUP450W

[goodpsusearch]

I got it some time ago.

Its 5vsb is ok but the psu refuses to power on.

The first time I shorted the green cable with ground a very bad smell got out of the psu. Since then nothing happens when I do that.

Nearly every cap on it is "Nicon". Never heard of them before. Are they good? There is a blown cap on the -12V that seems it was changed by someone who tried to fix it.


What do you think of this power supply? How many watts it can do? Is it worth repairing?

[stj]

Re: Konig CMP-PSUP450W

use your nose to find the source of the smell.
was it mellow like charcoal? that would be a capacitor.
if it was sharper it would probably be a semiconductor.

[370forlife]

Re: Konig CMP-PSUP450W

Looks fairly decent. I see a DM311 next to the primary heatsink, I do believe that is what makes the 5vsb, which would mean this dosen't have a 2 transistor 5vsb circuit. Soldering actually looks pretty neat, and even has silkscreening for two diode packs for the 12v. Decent sized heatsinks and a decent sized transformer.

First thing I would look for is blown primary switcher.

[Khron]

Re: Konig CMP-PSUP450W

I also noticed some burn marks between the two toroids. Could there have been some glue between them that dried up and went conductive?

And the right-most cap in the 2nd pic is visibly bloated (light blue, on the edge of the board).

[c_hegge]

Re: Konig CMP-PSUP450W

370, did you see how those four diodes were positioned? It would be pretty difficult to replace them with a rectifier. Also, there's a missing cap on the transient filtering stage.

goodpsusearch, It would probably be OK after the following:
1. Figuring out a way of replacing the four diodes next to the primary caps with a rectifier
2. Adding the missing cap
3. Replacing the secondary caps.

For now, though, I think that the four diode treatment limits it to 250 watts

[370forlife]

Re: Konig CMP-PSUP450W

It looks like it's silkscreened for a bridge rectifier under those diodes, if not all you have to do is make sure the + leg on the bridge rectifier goes to the + on the main caps, the - leg goes to the - on the main caps, and the AC legs connects to the AC. The missing X cap is on purpose, as the PPFC inductor gets in the way, thats why theres that daughterboard on the receptical that has most of the transient filter on it.

[c_hegge]

Re: Konig CMP-PSUP450W

OK, forget adding the missing cap then.

[everell]

Re: Konig CMP-PSUP450W

...did you see how those four diodes were positioned? It would be pretty difficult to replace them with a rectifier.

It would probably be OK after the following:
...Figuring out a way of replacing the four diodes next to the primary caps with a rectifier

For now, though, I think that the four diode treatment limits it to 250 watts

Why would you say that? From the pictures, the diode is 1N540x which would be a 3 amp diode. Running on a 220 volt power line, they should be able to handle 660 watts. These diodes would be better than a bridge rectifier with 2 amp rating! My opinion: leave the diodes alone and recap the power supply. Looks like a pretty good one to me.

[ratdude747]

Re: Konig CMP-PSUP450W

Why would you say that? From the pictures, the diode is 1N540x which would be a 3 amp diode. Running on a 220 volt power line, they should be able to handle 660 watts. These diodes would be better than a bridge rectifier with 2 amp rating! My opinion: leave the diodes alone and recap the power supply. Looks like a pretty good one to me.

who would have ever thought that the 4-diode treatment was a good thing? i guess it is an exeption to the rule.

[goodpsusearch]

Re: Konig CMP-PSUP450W

use your nose to find the source of the smell.
was it mellow like charcoal? that would be a capacitor.
if it was sharper it would probably be a semiconductor.

It was sharp and awful. I think it came from the secondary side. Not sure where exactly..

First thing I would look for is blown primary switcher.

I checked it with my multimeter in diode mode and nothing appears shorted. I don't know what values would indicate there is a problem with it.

I also noticed some burn marks between the two toroids. Could there have been some glue between them that dried up and went conductive?

And the right-most cap in the 2nd pic is visibly bloated (light blue, on the edge of the board).

Even if the glue got conductive I thought that the coil conductors were insulated..?

c_hegge, I always replace the 4 diodes with a bridge rectifier. I've got plenty of 4 amp and I could also find a 6 amp for free if this is best for that psu.

As for the missing X cap, I could try to fit a small one from another psu.

At the moment I try to make it work... and my recent experience with another psu isn't encouraging...

[robert]

Re: Konig CMP-PSUP450W

The output inductors (large toroid cores) are discolored from overheating. Iron powder cores are irreversibly damaged by too high temperatures, so these inductors need replacement.
However, its a typical piece of sh!t power supply, so the correct place for it is the trash bin.
Repairing a $15 PSU with $10 of parts and at least 2 hours for winding new inductors just isnt worth it, just get a better one instead.
Not much of a line filter, no soft start NTC, cheapest parts possible.

[370forlife]

Re: Konig CMP-PSUP450W

The thing really isn't that bad. It isn't that cheap if it uses single transistor forward instead of half bridge with a TL494 or similar. It also dosen't use the cheap 2 transistor 5vsb circuit, uses an actual DM311. It looks like it has provisions to be 2 transistor forward.

But I agree with the 5v/12v choke, that will need to be replaced as well as add a NTC thermistor, but you could pull those out of a different power supply if needed.

[mur]

Re: Konig CMP-PSUP450W

It isn't that cheap if it uses single transistor forward instead of half bridge with a TL494 or similar.

The irony is that almost every powmax/leadman uses single transistor forward with a uc384x pwm chip.

[370forlife]

Re: Konig CMP-PSUP450W

Leadman dosen't do everything wrong. Though I believe the only reason they use a single transistor forward is because you can buy 1 low capacity transistor for less than 2 low capacity BJT's.

[japlytic]

Re: Konig CMP-PSUP450W

Nicon has some affiliation with Fuhjyyu: http://www.fuhjyyu.com.tw/com.htm
Nicon caps used a "peace symbol" vent in the past.

[everell]

Re: Konig CMP-PSUP450W

I think I see a problem area in your power supply. I made a red circle on the pc board picture. On the right side you can see evidence of arcing. These traces go to the supervisory chip, a WelTrend WT751002. On the left side is a trace that looks like it has been repaired by placing a wire on a damaged trace and soldering it in place.

I have looked at Mouser and Digikey - our two most popular sources for semiconductors here in the USA. They do not carry any WelTrend semiconductors. This may be an indication of their quality. Perhaps someone else can comment on that.

If you want to change the supervisor chip - looks like most any of the supervisor chips that have 510 in their number should work. Like TL4510 or LS7510, etc. Just make sure it is a 8 pin chip, and check the datasheet for the replacement chip. For a datasheet on the WelTrend WT751002, just google it.

[goodpsusearch]

Re: Konig CMP-PSUP450W

Can I replace the original choke on the left of the photo with the one on the right?

The -5V wire will not be used.

[goodpsusearch]

Re: Konig CMP-PSUP450W

I installed it anyway and now the psu works!

The choke sits on a diode, I hope this is not a problem.

goodpsusearch, It would probably be OK after the following:
1. Figuring out a way of replacing the four diodes next to the primary caps with a rectifier
2. Adding the missing cap
3. Replacing the secondary caps.

For now, though, I think that the four diode treatment limits it to 250 watts

I added a 6A bridge rectifier. It is more than enough for that power supply

I also added a X cap, that hopefully will not get in the way of the passive pfc.

Not much of a line filter, no soft start NTC, cheapest parts possible.

I added an inrush current limiter too.

Soldering actually looks pretty neat, and even has silkscreening for two diode packs for the 12v.

About that, I can replace the MBR20100CT schottky rectifier with 2x F12C20 fast recovery rectifier.

Is this going to improve 12V line?

[Th3_uN1Qu3]

Re: Konig CMP-PSUP450W

Leave the MBR20100 in place, a Schottky will always be better than a fast recovery. Schottkys drop less voltage thus heat up less.

[370forlife]

Re: Konig CMP-PSUP450W

^^ What he said. I would only do it if they were F16C20's. The efficiency loss wouldn't be worth the extra 4 amps. If you can find another MBR20100CT, that would be the best option.