Hello all,
as a beginner electronics hobbyist, after a few years I would like to place another post on this Forum section, given that I did not succeed in finding any useful advice among the other posts.
Over the last years, I have been using a PowerEdge Dell Server with two redundant PSUs, namely the 750W F750E-S0 ones (aka 06W2PW). Unfortunately, last summer one of them failed (perhaps owing to an overheating), and the server had for working to take into account the other one only. Of course I opened and tried to troubleshoot the failed PSU, but each cap I tested seemed to be fine both as regards its onboard capacitance and ESR values. Also other components seem to be fine, but I did not test all components extensively.
Moreover, since I had no luck to find any schematics of F750E-S0 in the web, I had to reverse engineer this to me rather complex PSU (much more than a standard ATX) and discovered myself some interesting features, such as its active PFC section (with its switch-off relay) and two separated secondary rails (one of which lies in a soldered, extra-miniboard difficult to access and troubleshoot). On the other hand, I did not investigate the failure any further, and put the pieces of the PSU in a box.
Now that the other PSU is also failing, my server has gone eventually off, and so I need to find a solution for both the redundant PSUs.
Anyway, I observed a strange behaviour in the last failing PSU (frankly, I don't know whether it was also present in the former failed one), through which the expert eyes of the community could hopefully address me to a solution to the trouble: when I pull off the PSU, then I put it back to its housing and press the server on button, apparently nothing happened and the PSU troubleshoot LED is off, but after say 5-8 mins (and some occasional and random noises and clicks), the server "magically" starts and the LED is green (the action also occurs in the PSU only, therefore it is not related to the server motherboard or its peripherals).
Of course, that behaviour (which I guess will only last for a short time) makes anyway the server unstable and I have to fix it, but I guess that the some-mins-delay in powering on might be suggestive of a failure of (bad)caps capacitance. But which one(s)? Have I to investigate in the primary or secondary circuit to find the culprit?
Your attention and possible help will be greatly appreciated. and I also think that your hints may be useful to other redundant PSU servicers.
Thanks
as a beginner electronics hobbyist, after a few years I would like to place another post on this Forum section, given that I did not succeed in finding any useful advice among the other posts.
Over the last years, I have been using a PowerEdge Dell Server with two redundant PSUs, namely the 750W F750E-S0 ones (aka 06W2PW). Unfortunately, last summer one of them failed (perhaps owing to an overheating), and the server had for working to take into account the other one only. Of course I opened and tried to troubleshoot the failed PSU, but each cap I tested seemed to be fine both as regards its onboard capacitance and ESR values. Also other components seem to be fine, but I did not test all components extensively.
Moreover, since I had no luck to find any schematics of F750E-S0 in the web, I had to reverse engineer this to me rather complex PSU (much more than a standard ATX) and discovered myself some interesting features, such as its active PFC section (with its switch-off relay) and two separated secondary rails (one of which lies in a soldered, extra-miniboard difficult to access and troubleshoot). On the other hand, I did not investigate the failure any further, and put the pieces of the PSU in a box.
Now that the other PSU is also failing, my server has gone eventually off, and so I need to find a solution for both the redundant PSUs.
Anyway, I observed a strange behaviour in the last failing PSU (frankly, I don't know whether it was also present in the former failed one), through which the expert eyes of the community could hopefully address me to a solution to the trouble: when I pull off the PSU, then I put it back to its housing and press the server on button, apparently nothing happened and the PSU troubleshoot LED is off, but after say 5-8 mins (and some occasional and random noises and clicks), the server "magically" starts and the LED is green (the action also occurs in the PSU only, therefore it is not related to the server motherboard or its peripherals).
Of course, that behaviour (which I guess will only last for a short time) makes anyway the server unstable and I have to fix it, but I guess that the some-mins-delay in powering on might be suggestive of a failure of (bad)caps capacitance. But which one(s)? Have I to investigate in the primary or secondary circuit to find the culprit?
Your attention and possible help will be greatly appreciated. and I also think that your hints may be useful to other redundant PSU servicers.
Thanks
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