Fsp350-60hlc

[pdavid]

Re: Fsp350-60hlc

So I replaced the parts and the psu worked... for about a minute! Then R80 blew up. Until that 5vsb and ps-on signal were present and good. Then BAM! It was loud...

I used an IRFP 460 FET to replace the shorted 9N50C.

I decided to throw it out if it turns out bad, but it's actually getting more interesting so I'm going to keep trying until it's fixed for good.
R80 is blown, it goes to the tiny board where the CM6800 controller is. What now?

[pdavid]

Re: Fsp350-60hlc

So, since last time I managed to fry the cm6800 combo I decided that this thing is too tough nut for me to crack. I just put it on my parts pile for now.

[everell]

Re: Fsp350-60hlc

I have a Sparkle (Fortron) psu that looks very much like yours, even the circuit board. Having gone in circles fighting the same problems, I think your booster coil is the trouble maker. For the psu to run a minute or two before going "bang" makes me think that the coil is heating up then shorting. I don't think you are going to be able to fix it until you replace that coil! At this point, measure the APFC FET. It will probably be shorted. R10 will probably be open again. R80 is the current sensing resistor going to the CM6800. Being blown, that means HIGH current which most likely blew the CM6800 chip. Might have blown the two diodes between CM6800 pin 3 and ground. Lots of damage, but it can be fixed.

I traced the circuit and made a crude drawing when I was fixing my psu. Perhaps it will be of some help to you.

[pdavid]

Re: Fsp350-60hlc

I have a Sparkle (Fortron) psu that looks very much like yours, even the circuit board. Having gone in circles fighting the same problems, I think your booster coil is the trouble maker.

That is a great hint, Thanks!
I have access to coated cooper wires, all kinds of gauges. To make a coil like that, I don't know... I've only made for crossover circuits and such.

Tracking back using your schematic, things look kind of the same. I'll try to figure out something in the weekend.

[pdavid]

Re: Fsp350-60hlc

This pfc coil is done for. At least I know now. Also, I don't want to waste expensive 20A fets, so will experiment with irf 840 or 740 I guess. Got a new 6800 combo, fixed up it's board, now to make a new coil... lots of turns

[pdavid]

Re: Fsp350-60hlc

It works! I got an apfc coil from a similar psu with the same pcb. Now I have a known good psu without a pfc coil I might just put it back. I just wanted to know what will happen.

[everell]

Re: Fsp350-60hlc

Great job!

Now you can try rewinding the old coil and see if that works!

[c_hegge]

Re: Fsp350-60hlc

Nice work.

You could also try modding the heat sinks.

[ben7]

Re: Fsp350-60hlc

Hmm, I would use a larger APFC coil too, especially if it gets hot enough to burn off the insulation over time!

-Ben

[everell]

Re: Fsp350-60hlc

The booster coil should not run hot enough to burn the insulation off the wire. If so, some Chinese engineer designed the circuit using a cheap inferior core material. I would expect the booster coil to get hotter when used in countries with 110 volt power sources. I think Hungary has 230 volt power. If so, that coil should be running cool or I would think there is a design problem.

Consult our Romanian engineer for proper core to use and rewind the coil using same diameter wire. I have measured several of these booster coils and all were in the 470 to 500 uHy range.

[pdavid]

Re: Fsp350-60hlc

Consult our Romanian engineer for proper core to use and rewind the coil using same diameter wire.

Will do. I hope I'll have time to get this psu thing fixed up. Everything runs cool now. And yes we have 230V mains since 1998.

[pdavid]

Re: Fsp350-60hlc

I still haven't got a coil, I put back the original to the psu I got it from and...
well, this is new
Ps on is 3.1V, 5vsb is ok, but no power good signal. Swapped back the coil to the other one and it works.
It's definatelly not the coil. I don't remember how I got this psu, but I think it was working. So much fun with these fortons.