Can a Bestec be made good?

[ratdude747]

Re: Can a Bestec be made good?

my friend gave me a best tec 250 12e for free,its a great power supply, i took it apart and no bulging caps, it powers a athlon xp system now with bulging GSC caps on the mobo theyve been bulged for a couple years but haven't blown up, my freind also gave that board for free, its a albatron km266pro he said he saw smoke come out of a ram slot but ive never had problems with it, the chipset fan seized so i put some 10w 30 in it and its been good for 2 years. iam gonna run it till it blows.

WARNING! when a 12e blows it takes out the mobo with it!!!!

you better not do that. for future reference, it is generally not advised to Run it til it blows". especially the 250-12e. i guarantee a 18v 5vsb will fry your mobo.

i would personally find another psu to replace it with. recap at your own risk.

[BigTroll]

Re: Can a Bestec be made good?

my friend gave me a best tec 250 12e for free,its a great power supply, i took it apart and no bulging caps, it powers a athlon xp system now with bulging GSC caps on the mobo theyve been bulged for a couple years but haven't blown up, my freind also gave that board for free, its a albatron km266pro he said he saw smoke come out of a ram slot but ive never had problems with it, the chipset fan seized so i put some 10w 30 in it and its been good for 2 years. iam gonna run it till it blows.

[cubecompmtdx]

Re: Can a Bestec be made good?

If you do some research, you may find out that the 5vsb flaw is in the Bestec units marked "250-12E". From what I have heard, the 300w 12E units have much better standby circuits. As long as your emachine systems don't have the 250w 12E Bestec units in them, then you should be okay.

[Wizard]

Re: Can a Bestec be made good?

Buy a good PSU like seasonic and replace one POS and rebuild this PSU, then swap this repaired PSU in another POS. so on.

Cheers, Wizard

[bojoe]

Re: Can a Bestec be made good?

I see I need to recap or replace all the Bestecs - very soon. They are not really servers, but they all are Point-Of-Sale stations, and it's awful when they go down.
Thanks for all the answers..
bojoe

[everell]

Re: Can a Bestec be made good?

The guys on this forum give good advice concerning the need for good capacitors - and replacing problem brands. Another problem with the Bestec is the 5VSB design. You can look at the pc board and see that most of the heat discoloration is in the 5VSB circuit. Those models using the two transistor 5VSB have no protection against overvoltage/overcurrent problems. My solution was to remove the transisors and associated circuitry and install a DM311 chip on a seperate piece of perf board. This chip provides the needed overvoltage and overcurrent protection. How to do it?...see my thread posted a few days ago titled Bestec ATX250-12E up and running. I posted photos and circuit diagrams. This modification may not be necessary if a later model has an IC for the 5VSB circuit. Caution: be sure the DC voltage has discharged from the two big capacitors before working on this PS, they charge to 332 volts and will bite!

[Wizard]

Re: Can a Bestec be made good?

Wattage doesn't determine the issues, the brand do. Bestec = trash.

Recapping it with quality capacitor helps but important to replace FAN with a ball bearing fan so you don't get a overheat on your hand (happened to me!).

Cheers, Wizard

[kc8adu]

Re: Can a Bestec be made good?

i recap these all the time.the "killer"cap is a 10@50 in +5stby.
it is in several locations depending on the rev.
i use a 22@50 fc
the 220@25 gets a 220@25 pw.newer ones use a 100@50.these get a 100@50 fm.
all the rest get 2200@6.3 mbz since i have an inexhaustible suppy of them.1800@16 mbz on +12 and -12.
they are just fine afterwards.would not put one in a server but i have a 300 in this box now.its a amd fx60 dualcore with 4gb ram and 6 146gb 15k scsi in raid 5.
been in it 2 years since i recapped it.i have ben keeping a close watch on it but as i suspected years ago they are fine when good parts are used.they also have remote sense on +3.3 and +5.

[Leopard]

Re: Can a Bestec be made good?

So this problem is not limited to the 250W model only? Damn I better inform a good friend of mine to get rid of his 300W Bestec immediately.

EDIT: Wizard you got any pics of a Bestec? I would like to know which cap is the one that causes overvolting of the +5VSB.

[Wizard]

Re: Can a Bestec be made good?

Inherently bad design, only way you can make it semi-good is use *premium* caps in there, especially one key small cap that caused overvolting.

Other than that, I rather use a PSU with a true PWM IC built into one IC for standby power.

Cheers, Wizard

[bojoe]

Assuming that a Bestec 300 has not yet gone bad, (ie., volts still correct), can it be made "good" by recapping, or is it inherently bad by design?
I have 6 systems (Emachine\Gateways) running on Bestecs.
Thanks,
bojoe