Did I broke Fortron?

[Behemot]

Got this FSP300-60PN (PF). Seems like the good old platform with daughter board containing the compensation circuitry, now with 12cm fan.

This one was very nastly full of dust, several caps bulged. Did complete recap, including the small ones on the daughter board. Tough work, my new solder pistol is too powerful Burned some traces but it should be all right…at least I think so

It is working almost fine, with just one small problem…voltages are terribly up Don't know whether something is shorted or broke somewhere, I don't think so, Fortrons are sensitive on this and usually do not even start in such occasions. So maybe too low ESR now? There were some nasty brands before recap (usual Teapo and OST but Jamicon also).

I tried to play with potentiometers, best result is some 15 V on +12 V, 6 V on +5 V SB and so on. One potentiometer gives lowest values when there is lowest resistance on him, I was thinking of lowering it from 8 ohms even lower, to some 1-2 ohms, or even using wire connection…? Otherwise it has big spread, up to several kiloohms.

And if the regulation is based on +5V SB, may I somehow lower the voltage so the rest will go down too? Cause the SB rail cannot be regulated by that potentiometer.

[Th3_uN1Qu3]

5vsb is always its own power supply. Are you really really really sure your multimeter is working right? A bad battery on a cheap 830B type meter gives higher readings than normal.

[Behemot]

Mmm, well it is true that I have very weak battery these days in my multimeter It is some FK Technics, this or similar: http://www.elektroeden.cz/digitalni-...8500+dp113541/

I hooked it to a motheboard with bad BIOS, it didn't burn, so, do you think it would be wise to hook it to a good MoBo and use internal voltage measurement?

ADD// fucking shit, U right. I should have realized it is no longer useful when the beeper inside the multimeter ceased to make any sound on the diode tester. Not mentioning I kept it on AGAIN the whole last night.

Man I think I will leave my school. I can learn much more here on the forums than in the school. PCBONEZ could even teach me how to operate NPP, so really, what's the point in visiting to my university?

[Th3_uN1Qu3]

Originally Posted by Behemot

Mmm, well it is true that I have very weak battery these days in my multimeter It is some FK Technics, this or similar: http://www.elektroeden.cz/digitalni-...8500+dp113541/

That's a 830B with beeper and temperature, aka a 838. It adds a beeper to the diode checker and sacrifices the 200uA range for a temperature probe. It suffers from the same issues the 830B does, being based off the same chip. Low battery will give higher readings, and won't always be detected by the onboard "battery low" indicator.

And yes i agree that uni in some countries is basically pointless and doesn't teach you sh*t. Still, you need that piece of paper called a diploma.

[Behemot]

Another good PSU for sale

Well this school is able to gimme much, but I am begining to dislike it anyway. I think am just not for this kind of „high-end“ math and physics and stuff. Also lazy, but I definitelly dunno liek it as I did at secodnary grammar school (currently at faculty of nuclear and physical engineering studies)

I suggest you to write down how many beers I own you, I definitelly won't remember that. Make it two now

[momaka]

I had a similar experience with my cheapo 830D. A while back I was testing a trash-picked PC. When I checked the 5VSB, I immediatelly unplugged it as I was unsure if it would damage my (one and only) favorite keyboard and mouse (that's all I had for testing back then). The 5VSB read nearly 6V. Seemed strange as the power supply was a nicely-built Astec with all Japanese caps and a proper chip-based 5VSB circuit. When I tried a different power supply (before suspecting my meter), it too read really high on the multimeter. Finally checked it against a known-good source and it read 2V over. Changed the battery and everything was back to normal.

Originally Posted by Behemot

Man I think I will leave my school. I can learn much more here on the forums than in the school.

I feel the same way too. The college I go to is only teaching us theory. I was testing a DVD drive laser today to see what kind of current would give me the required wattage output (needed 2 *good* multimeters, so I couldn't test this at home). The TA who instructs our lab had no idea which was the laser diode, and I had only 2 components on the breadboard - a MOSFET and the laser diode . We also have a few "smart" kids in the lab that always have trouble building the circuits. Took them the entire class time (almost 3 hours) to complete the midterm. I did mine in 10 minutes - 5 for getting the probes and wires, and 5 for actually building the circuit and answering the questions . But I fail at theory, so... dropping out might happen sooner than later.

[rogfanther]

Theory is important, to understand the reasons things work / don´t work. It is hard to endure some classes, more so when the teacher is not that good, but, like eating vegetables, it is an important thing.

We had that kind of lab classes, where the girls with the top grades, those who would write down in their notes even when the teacher sneezes these girls would stare at the logic simulators, not knowing what to do. And us, the plebeian portion of the class, would have ours up and running in the first hour, even with some bells and whistles...

But to be fair to the ladies in question, when writing the essays about what we had done, we would have difficulties too, because we knew how to do it, we knew how and why it worked/didn´t worked, but were not able to explain in an adequate manner.

[Behemot]

Did one testing of a recapped board today when noticed the board shouts about having just 2,59 V on +3,3V rail. I've stared as calf at barn-door, but multimeter (this time with good battery) confirmed it. Well, I should have checked it after my playtime Its fine now with 12,15 V and 3,35 V no load, 12,3 V/3,34 V mild load

[b700029]

Originally Posted by Th3_uN1Qu3

5vsb is always its own power supply. Are you really really really sure your multimeter is working right? A bad battery on a cheap 830B type meter gives higher readings than normal.

That almost sounds like an attempt at fail-safe... because a meter that is reading under the real voltage could lead to worse results than one that's reading over.

[tom66]

Cheap Chinese meters don't care about safety. It occurs by coincidence - the voltage reference falls when the battery is too low.