Questions on recapping a Seasonic SS-300FS

[Shocker]

Re: Questions on recapping a Seasonic SS-300FS

Wouldn't it be easier to replace the original 1M resistors with 510k (since they're in series)???

Also, why are two diodes used in the mod???

[everell]

Re: Questions on recapping a Seasonic SS-300FS

Wouldn't it be easier to replace the original 1M resistors with 510k (since they're in series)???

Also, why are two diodes used in the mod???

Three 330k resistors works great. Two 510kresistors should work fine. One 1 meg will work most of the time. Your choice.

One diode is the high speed switching diode to rectify the pulses coming from the feedback winding which provides power to the pwm chip. The other diode is a zener to protect the feedback input from going overvoltage. The zener is not essential. If you want to be "economical" you can use one 1 meg resistor and eliminate the zener. Then hope for the best. If it blows up your power supply, then you can have fun fixing it!

[Shocker]

Re: Questions on recapping a Seasonic SS-300FS

I meant the two identical rectifier diodes in your circuit. I know what the zener is for.

[raresvintea]

Re: Questions on recapping a Seasonic SS-300FS

I can buy a power supply like this for a couple of bucks, that is working. What is needed to be changed to be a realible power suplly in the future. The consume of the sistem is about 70-100W.

By changing parts i mean to change caps. Atfer the refurbisment i want that this PS last more longer.

[raresvintea]

Re: Questions on recapping a Seasonic SS-300FS

Can be done this mod using TOP222 or viper22A to be done in this power suplly?? How?

[gas_liosia]

Re: Questions on recapping a Seasonic SS-300FS

Here's an overhead shot and one from a more oblique angle. I notice that there is a missing diode near the OST cap in the middle of the board, where the 5 Vsb presumably is. The board is discolored there. This unit is supposed to be new (it was sold to me as new by hypermicrosystems), so if that's true it must have come from the factory this way. If that OST is in the 5 Vsb section, it must be more important to have a low ESR, high ripple cap there.

I have noticed that some boards, namely the FIC VA-503+ and FB-11 boards, come double drilled in some capacitor spots. I'll have to remove the board to see if it's double drilled in spots. Now I'll need to make a simple bleeder for that 220 uF 400 V Hitachi before any caps I order arrive. I don't want to simply short it out if I'm not replacing it.

Which reminds me; is it likely that the caps would need reforming since the unit is something like seven years old and hasn't had power applied in a long time?

Hello! I'm new to your forum and I 'm happy to be between electronic-lovers! I have the same power supply and I have a similar problem. There is a resistor (R123) just between the diode you say is missing and the electrolytic capacitor (C24-47u). This resistor has been shorted to mine and the only colors I can recognize are the first two of three (brown-red) and I'm not sure for the third one. Could someone help me with that? I searched for a schematic but I didn't find anything...