Just got another L&C.....

[Dan81]

Re: Just got another L&C.....

something has sparked and blown away part of the resistor leg!!

Okay...any ideas what value was it?

[stj]

Re: Just got another L&C.....

something has sparked and blown away part of the resistor leg!!

[Dan81]

Re: Just got another L&C.....

this area.

What's with it? It just seems darkened but that's it.

Do you mean I should replace the diode and the blue cap?

[stj]

Re: Just got another L&C.....

this area.

[Dan81]

Re: Just got another L&C.....

Before replacing the fuse, check with the diode mode of your multimeter the 4 diodes, the 2 switching transistors, the 5vsb transistor and anything else that could have gone bad. The 2003 IC could be bad too. Check it and if most of its pins look shorted then you can assume it is bad.

Also check the underside of PCB and post a photo of the soldering.

Checked the underside of the PCB. No burn marks on the underside.

Now,more pics as you asked:

Replaced fuse and NTC thermistor


Replaced 2N60A transistor w/ thermal pad


Solder side (brown stuff is lots of rosin core I used)


The transistor w/thermal pad and NTC thermistor came from a Codegen 200X 350W PSU I discarded.

[stj]

Re: Just got another L&C.....

primary side of the standby is blown, look between the standby transformer & heatsink!

btw, that foto is a good demonstration of why we are supposed to use ceramic fuses on psu's!

[goodpsusearch]

Re: Just got another L&C.....

Before replacing the fuse, check with the diode mode of your multimeter the 4 diodes, the 2 switching transistors, the 5vsb transistor and anything else that could have gone bad. The 2003 IC could be bad too. Check it and if most of its pins look shorted then you can assume it is bad.

Also check the underside of PCB and post a photo of the soldering.

[Dan81]

Re: Just got another L&C.....

THE ntc thermistor. If it cracks it indicates something is shorted.

Well,what can I do then? Replace the fuse and the thermistor? Or replace both and then proceed with replacing the switching transistors (guess they're the ones on the heatsink next to the primary caps)?

[goodpsusearch]

Re: Just got another L&C.....

THE ntc thermistor. If it cracks it indicates something is shorted.

[Dan81]

Re: Just got another L&C.....

The caps look ok. Maybe the switching transistors shorted.

I don't think it's that either. I've had a Premier like this one with the switching transistors shorted and it wouldn't turn on at all. Just a fan twitch and that was all.

I'd say the 5A fuse it has would have been bad itself,but not sure about that.

Also,I checked the green thingy next to it (does anyone know what is it?) and it's cracked.

[goodpsusearch]

Re: Just got another L&C.....

The caps look ok. Maybe the switching transistors shorted.

[Dan81]

Re: Just got another L&C.....

Did the fan seize?

No. Entire PSU was brand new,with very light dust.

[goodpsusearch]

Re: Just got another L&C.....

Did the fan seize?

[Dan81]

...and it blew.

Fuse blew when I plugged it in,and it also TRIPPED. Few sparks went like 4th of July's fireworks.

PSU is ANS LC-B350ATX. Has voltage selector (set to 230V btw),chip of the year 2003,diodes on a bracket,our usual 4 diode treatment ,all the signs of a PSU worse than Powmax.

Strange thing is the fan is a Ruilian Science RDM8025SA. IIRC Deer/L&C love using Globe Fans,so this is quite weird.

Also,have a laugh at the output it claims:

3.3V - 28A
5V - 35A
+12V - 16A
-12V - 0.8A
-5V - 0.3A
+5VSB - 2A


A shot of the carnaige. Look at the blown fuse . It has a bit of copper wire underneath it for a reason I really don't understand.