by Wester547 » October 10th, 2014, 4:25 pm
The +3.3V rail uses a single 20A part, SBL2060CT, not SBL3060CT, judging by the picture. Maybe the fan's lack of lubricant caused it to slow down severely which might be one reason why the 2SK2611 blew (you said the Hipro was very loud in the polymod test at 300W - this fan should have been equally loud at 300W-450W but was not...). I have never understood why LTEC last so long in Newton/Delta 250W-305W power supplies that almost look identical to the Hipro posted here but why LTEC can't make it in these units. I have opened up and compared Newton units to these and I do not see the difference. Both have equivalent toroids, equivalent fans, equivalent heatsinks, similar fan controllers, equal ventilation, and similarly spec'd schottkys and MOSFETs on the primary and secondary along with the bridge rectifiers and bulk storage (though Newton have a smaller output filter on the secondary but maybe that's because the ripple frequency may be higher)... only that Delta use the LTEC LZG series instead of LZP so maybe LZG is more reliable (LZG is rated up to 7,000 hours and LZP only up to 4,000).
Even with the 2SK2611 that blew (probably because the efficiency might have been below 70% at 450W load, at which point the chances for survival dissipates), I bet once you oil the bearings that the fan would spin faster (that would probably account for the higher exhaust temperature) and that would still easily make it a 350W PSU (once you replace the main switcher that is). Not bad. Also, hard to believe how low the ripple is on +5V, +3.3V, +12V, and -12V without linear regulation as well as +5VSB... it is odd that this unit didn't shut down. You'd think at 450W load, with that fan slowing down, that the unit would have shut down due the thermistor on the secondary heatsink detecting that the secondary heatsink had overheated...
Last edited by
Wester547 on October 13th, 2014, 8:28 pm, edited 1 time in total.