omega
Member
Last Activity: 03-03-2024, 04:21 PM
Joined: 03-08-2014
Location: Palermo
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Sorry, at present I can not switch on the PSU because, as you can see in a picture of mine (comment #6), I have removed the two big filter caps. I can only test the board turned off.... -
Actually, on the mainboard of the PSU there are two NCP5104 ICs. Only one of them (U1) has a cap (C14) between the pin 8 (VBOOT) and 6 (BRIDGE), but it is an SMD one and seems to be fine (about 200 nF). Also the diode on the right in the picture seems to be fine (0.6 V drop)....Leave a comment:
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as I wrote, and as you can see yourself in the first pic, this redundant PSU is a masterpiece of crowded component. I believe it might get hot with use. Anyway, the Capxon cap(s) I showed you is(are) buried in the secondary side of the daughter board which is difficult to extract and inspect. I think I would need low melt solder (which I don't have) to remove their many solderings....Leave a comment:
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Do you mean the picture of the hidden cap in the SB rail?...
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Thanks for your comment. In my case, in the daughter board (the standby voltage rail?) there is no electrolytic cap before the mosfet and the stepdown transformer. After that, there are one or two concealed Capxon 270 uF electrolytic caps, virtually impossible to reach & replace without desoldering the daughter board. Anyway I think they might have little to do as regards the huge startup-delay trouble because they work to rectify the transformer wave....Leave a comment:
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Oh I see. I can confirm you that in the primary side there is NO (little) electrolytic capacitor besides the two big ones, which however at the voltage of my testers seem to be both fine as regards both capacitance and ESR. In the primary section, there are just two red polypropylene and a few SMD ones (in the other side of PCB). Maybe that (component crowded) PSU does not follow the ATX standard. At this point I do not know what to check....Leave a comment:
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Thanks again for your hint! Actually, I have found that almost hidden cap beside the big one. Its specifications are 100 nF, 450 V. But I have tested its capacitance and it seems to be fine (140 nF), so as the big cap. Is it really the culprit of this delay? By the way: I would be happy if i could measure the high-voltage loss of these two caps (I have tested both caps through a standard capacimeter). Which is the right tool to accomplish these measurements?...Leave a comment:
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Thanks for your answers!
I did not make myself understood well. Once the PSU is started, the LED is green and the server wokrs fine.
Anyway, I will look for that "small starter cap", but if I remember properly, besides the security Y and X caps, the first caps in the primary circuit are the two big caps (at the centre of the picture), respectively 330uF 450V and 47uF 500V, topologically connected through a diode. I did not even understand that odd topology and the duplication of the big caps....Leave a comment:
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Troubleshooting of redundant F750E-S0 Dell PowerEdge Server
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... -
Re: Recapping of Asus P5B
dear goodpsusearch,
you are definitely right, if was a mistake of mine, thanks for the observation!
Though it may happen sometimes (it's my first time in years, I'm getting old), it is unbelievable that I did not notice myself. Shame on me! Anyway, I still don't explain why some others (correctly soldered) have got their bottom "stopper" moved in so short a time.
Any comment as regards the caps in Fig. 4? Are they OS-CON or simple through hole electrolytic? I still remember that in one out of 20 mobos I examined so far, I noticed...Leave a comment:
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Recapping of Asus P5B
Hi,
I would like to report my experience with thorough recapping of one of about twenty motherboards Asus P5B (aka P5B vanilla) which I have been using in machines for my present work.
Over the last years, I have been recapping few (unfamous) 820 uF 6.3 V caps, which had been getting bulged, with (almost) constant success.
So encouraged by my own experience and by readings of a number of threads here in BADCAPS, I realised that the TK cross semi-cut caps (Figure 1) had to be replaced, and I done it in a complete fashion with 19 original Panasonic FR series identical value... -
Re: Annoying heavy load-failure in Tecnoware Free Silent 500W
I see. I will. But in the meantime I could compare in terminal service the voltage curves of FAL501FS12 and VS450 (by means of SpeedFan). Even if the absolute values are nonsense, the latter is far more stable, even if it is full of CapXon caps!
I am almost sure that the resistors are of the same values except the R12 which is missing.
Money is undoubtedly important, but it is not everything. From this experience I learned so much about PSU,...Leave a comment:
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Re: Annoying heavy load-failure in Tecnoware Free Silent 500W
This to post bad and good news together
So far I recapped nine Technoware FAL501FS12 (just the secondary section), with replacement of the 12V rail diode as momaka suggested me, and had also time to test them "in the field" under stress load (100% CPU 24/7), as usual in my field of research.
The bad news is that some work, some not (namely I get the infamous ATAPI error 9 and 11). After checking the soldering of every "bad" PSU, have been trying for hours to give myself an explanation...Last edited by omega; 02-05-2016, 06:41 PM.Leave a comment:
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Re: Recapping of Corsair VS450
just as a curiosity: how can you be so accurate with ESR values? I read from you that you can guess milliohm! My dear Blue ESRmeter does not go beyond centiohm :-(Last edited by omega; 02-04-2016, 04:22 PM.Leave a comment:
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Re: Annoying heavy load-failure in Tecnoware Free Silent 500W
Momaka, thanks you so much for the steady support!
sorry a comma has been dropped out!
nominal is the value which has been printed n PCB
before (after) recap is before (after) the cure, with 21W load (or no load).
It's a pity that I cannot attach a Table
Yes, they all are FAL501FS2
I can also see that a place on the left of the red square you sketched is EMPTY. If I am remember, it is NOT missing, but this pic has...Leave a comment:
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Re: Annoying heavy load-failure in Tecnoware Free Silent 500W
Back to the main subject of this thread, now that I 've recapped nine PSUs FAL501FS12 I have some statistics of the voltages (most ATX are already under stress, I will let you know about the results). Most of the recapped follow the voltage schema depicted in post #56, however two PSU get following similar voltages:
nominal before recap, 21W after, 21W after, no load
12 V 12.4 V 12.7 V 12.9 V
5 V 5.5 V 5.4 V 5.4 V
5 VSB 5.1 V 5.1 V 5.1 V
3.3 V 3.4 V 3.3 V 3.4 V
–12 V –11.9...Leave a comment:
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Re: Annoying heavy load-failure in Tecnoware Free Silent 500W
Dear Momaka, thanks for your wide and thorough post!
In fact, the scenario is worse than you painted (see pic). Those resistors are 0.5 W, definitely!
Actually, I wondered whether I have to put some load to the 5 and 3.3 rails.
Here are the data:
nominal before recap, 21W after, 21W after, no load
12 V 11.9 V 12.1 V 12.4 V
5 V 5.2 V 5.2 V 5.1 V
5 VSB 5.1 V 5.1 V 5.1...Last edited by omega; 02-02-2016, 01:10 AM.Leave a comment:
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Re: Recapping of Corsair VS450
Difficult to read the value of this cap, even with a knife blade as a mirror. I will be confident once I desolder.
Thanks for your support!...Leave a comment:
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Re: Recapping of Corsair VS450
Sorry I forgot attaching the pics of the PSU.
The trouble is that most of the specifications omits just the ESR.
Anyway the CapXon series is GF except for the 12 rail, which is KF.
Yes, I am aware that good caps are rather expensive, but Momaka encouraged me to repair this PSU.
As regards the motivation of recapping, I explained it in another thread about Technoware recapping....Leave a comment:
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Recapping of Corsair VS450
Hi,
for a year I have got a still working Corsair VS450 PSU. While searching in this section I have found some traces of this topic in several threads but no specific one. Encouraged by your comments and my curiosity I opened it (so forgetting about its warranty) and discovered that it has been capped by poor quality only capacitors, which of course I would recap.
While I am not 100% confident of the respective rails (sorry I am still an amateur novice), here is the whle list of the capping:
Filter: 1x Aishi 180uF, 400V
Primary: 2x JunFu 2x 220uF, 25V + 2x JunFu...
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