Upgrade a 300watt noname power supply

[bauto601]

Re: Upgrade a 300watt noname power supply

Hello,
I am very busy with school and other computer things at the moment so i will work on it in the weekend but not on school days. So it can take a little longer before i will respond to your post.

[c_hegge]

Re: Upgrade a 300watt noname power supply

^
The part numbers on the transformers don't looks like L&C, neither do the heat sinks, and L&C have never used Fuhjyyu caps (whereas CWT love them).

The PSU in post #20 is an L&C, though

EDIT: Maybe I should add that the OP's PSU looks like it is from their ISO division, and so it lacks some of the usual CWT features, like green tape and CWT markings on the transformers.

[everell]

Re: Upgrade a 300watt noname power supply

The OEM for this PSU is Channel Well (CWT).

How can you tell that this is Channel Well and not Solytec/L&C?

[c_hegge]

Re: Upgrade a 300watt noname power supply

On your PSU, the BYQ28E is for the 12V, the STPS2045CT is for the 5V rail, and the STPS1545CT is for the 3.3V.

EDIT, you could use those other heat sinks, but maybe bend the fins outwards, that way, you will get some airflow between them

[TELVM]

Re: Upgrade a 300watt noname power supply

... I don't know which rectifier is what so i don't know which is the the 3,3, 5 and 12v rectifier. Can you tell me which rectifier is what? ...

The color of the output wires can give you a clue:

Often the +3.3V rectifier is aligned with the orange wires, the +5V with the reds, the +12V with the yellows.

To be sure test for continuity between the center leg of each rectifer and the orange/red/yellow wires.

[bauto601]

Re: Upgrade a 300watt noname power supply

Those rectifiers are fine. Use the BYV42E on the 12V rail, the MBR4045 on the 5V rail and the SBL4040 on the 3.3V Rail. Sometimes, if you unsolder the 4 diodes, the PCB will be screened for a rectifier as well. Do that and post a shot of what's under there.

Your new heat sink looks nice and chunky, although you may have to drill a couple of extra screw holes for the rectifiers. I'd install it with the overhang over the toroid coils and caps, not over the transformer. The other consideration is that you don't want the primary heat sink to be much smaller than the secondary one if the fans will have a speed controller, because the secondary heat sink (which controls the fans) could stay cool, while the primary heat sink is red hot, and the fans won't speed up.

To begin:
I don't know which rectifier is what so i don't know which is the the 3,3, 5 and 12v rectifier. Can you tell me which rectifier is what? The big heatsink is made of too thick material so it wil short some components on the pcb.. But from another psu i have these heatsinks:

Are these big enough?

Also, this psu has no fan control so it is making terrible noise when it's on. After replacing the rectifiers i am going to test the unit and a.fter the testing i am going to unsolder the diodes.

[c_hegge]

Re: Upgrade a 300watt noname power supply

Those rectifiers are fine. Use the BYV42E on the 12V rail, the MBR4045 on the 5V rail and the SBL4040 on the 3.3V Rail. Sometimes, if you unsolder the 4 diodes, the PCB will be screened for a rectifier as well. Do that and post a shot of what's under there.

Your new heat sink looks nice and chunky, although you may have to drill a couple of extra screw holes for the rectifiers. I'd install it with the overhang over the toroid coils and caps, not over the transformer. The other consideration is that you don't want the primary heat sink to be much smaller than the secondary one if the fans will have a speed controller, because the secondary heat sink (which controls the fans) could stay cool, while the primary heat sink is red hot, and the fans won't speed up.

[bauto601]

Re: Upgrade a 300watt noname power supply

Here a pictures of the power supply now:


All the parts i use in this power supply come from other (broken) power supply's. So i found this heatsink on a old broken power supply:

The red line on the big heatsink is the line that i am going to follow if i am sawing the heatsink in the right shape (is that good english )
I am going to place a fan at the front of the power supply and at the back of the power supply.

Here a picture of the new (ehhh.. from a old psu) rectifiers:


I can't find anything of the 1st rectifier.




Are these rectifiers good ones? And how can i replace the diodes with a rectifier? I also hear that i have to replace almost whole the power supply so this is going to be a job for the whole week

[Logistics]

Re: Upgrade a 300watt noname power supply

OP's PSU looks almost exactly like an Antec PSU I recapped in the past; either a PP-303X or an SL-350. Can't remember which one, but it looks SO familiar.

[c_hegge]

Re: Upgrade a 300watt noname power supply

That's how I'd do it on this PSU. With the shape of the heat sinks, they will work better with front to back airflow, not 90 degree top to back.

EDIT: I went on a similar venture to this with a Rexpower PL-400 power supply. You mey find that thread interesting - https://www.badcaps.net/forum/showthread.php?t=11247

[TELVM]

Re: Upgrade a 300watt noname power supply

... i can also add a second fan that blows right on the heatsinks like here:
http://laptopshopcyprus.com/41-247-l...aptop-shop.jpg

I'd put the second fan this way:

Straighter flow and less turbulence = better cooling.

[Pentium4]

Re: Upgrade a 300watt noname power supply

Hello, here i am again
Thanks for the tips P4! I am going to replacing the secondary rectifiers tomorrow. You say that i need a bigger heatsink on the secondary, i can do this but i can also add a second fan that blows right on the heatsinks like here:
http://laptopshopcyprus.com/41-247-l...aptop-shop.jpg

Another question: I am going to replace the 3,3/5v rectifiers for bigger one's that are skottky. But at the 12v there are only holes in the pcb for a small rectifier. So i am going to replace the 12v rectifier to another stronger rectifier that is also a small one but that one is not skottky. Tomorrow i will post pictures and specs of the new rectifiers.

That extra fan would help a lot! Especially if it's always getting 12V. Yeah that's typical of an older design. A 20A schottky for 12V would still be a good improvement. And yeah there's nothing wrong with your english, it's better than a lot of native speakers in my area

[goodpsusearch]

Re: Upgrade a 300watt noname power supply

13007s. I can never pull more than about 250W from them without blowing them up. I'd replace them with 13009s, D209Ls, or 2SC3307s

+1

250W max

300W peak for couple of seconds maybe

[bauto601]

Re: Upgrade a 300watt noname power supply

Hello, here i am again
Thanks for the tips P4! I am going to replacing the secondary rectifiers tomorrow. You say that i need a bigger heatsink on the secondary, i can do this but i can also add a second fan that blows right on the heatsinks like here:
http://laptopshopcyprus.com/41-247-l...aptop-shop.jpg

Another question: I am going to replace the 3,3/5v rectifiers for bigger one's that are skottky. But at the 12v there are only holes in the pcb for a small rectifier. So i am going to replace the 12v rectifier to another stronger rectifier that is also a small one but that one is not skottky. Tomorrow i will post pictures and specs of the new rectifiers.

[Pentium4]

Re: Upgrade a 300watt noname power supply

If you're going to upgrade to 30A rectifiers then you need a better heatsink for the secondary. You don't HAVE to use japanese caps on the input but it doesn't hurt, and I'd use 680uF caps instead of 470. I would add a bridge 6A rectifier to replace the diodes. They look decent but their ratings go down a lot when they get hot. I'm guessing that thing has probably 1 or 2 caps for 12V filtering so definitely increase the capacitance on those caps, at least 2200uF, preferably 3300uF. Replace those orange ceramic discs on the primary with matching Y caps, and if you're up to it solder an X cap to the AC receptacle. The transformer looks good enough...Also, I would replace the fan with a high quality ball bearing fan
Edit: didn't realize hegge mentioned some of the same things

[c_hegge]

Re: Upgrade a 300watt noname power supply

13007s. I can never pull more than about 250W from them without blowing them up. I'd replace them with 13009s, D209Ls, or 2SC3307s

[bauto601]

Re: Upgrade a 300watt noname power supply

Here are they:

[pdavid]

Re: Upgrade a 300watt noname power supply

Had like two dozen of these CWT psus at work and even after six years (24/7) they sort of worked. Standby gets a little cooked and sometimes the primary capacitors (Koshin) start to bulge.
If you can do as others suggested and put an even bigger transformer, (like ERL35) 13009 primary transistors and 680uF capacitors plus recap and upgrade the secondary I think this psu would be a good emergency spare. I hope this helps.
Also here is one of the lowest-of-the-low versions of this psu claming 300W but exploding at 200W.

[bauto601]

Re: Upgrade a 300watt noname power supply

Yes.

I'm not at home at the moment, tomorrow i wil post the specifications of them.

[goodpsusearch]

Re: Upgrade a 300watt noname power supply

Do you mean the components on the primary heatsink?

Yes.