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| Thread ID: 119922 | 2011-08-17 01:18:00 | Random crashes after system upgrade. | jackie.t (16504) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 1223886 | 2011-08-23 23:58:00 | I was simply pointing out that while some here are saying it "IS" the PSU causing the problem, and jackie . t buys a new one which clearly is not in the budget, and it doesn't fix the problem, would those people go "oh my mistake, I'll refund the money" -- yeah right . A good tech / repair place would change the PSU with a "loner", and if the problem is solved then a new one can be purchased . I would have suggested opening the thing and doing a visual inspection, if the capacitors were bad then replace it . However jackie . t didn't strike me as the type who would want to open the PSU and I figured it would spark off some people to go on about how dangerous such an exercise is . (Which I do agree with IF the person who's doing it has no clue, wants to fully disassemble and then poke their tongue onto the primary filter capacitor terminals etc, but simply removing a cover and looking - not touching - is really not any more dangerous than changing a light bulb if you forgot to switch off and accidentally stuck your finger in the socket!) I didn't bother suggesting a PSU swap (which yes, I probably should have) as most of the time when I suggest this people say they don't have one to swap with, but considering it's a Hyena and old it's my opinion the thing should be replaced anyway . From my own experiences with PSUs, cheap ones like that past a certain age have failed capacitors . And of course that is no guarantee that ALL cheap PSUs in the world will be the same (and possibly your server PSU included) but what I've seen is backed up by other people (badcaps . net forums) so I don't believe that assumption is likely to be wrong most of the time . |
Agent_24 (57) | ||
| 1223887 | 2011-08-24 00:21:00 | Not being rude, but not every thing that fails is due to bad caps. :) While the PSU may very well be the cause of the problems, If the service people were any good, or actually cared about their work/ customers, they would track down where the actual problem is, not just fob it off saying they dont know and randomly buy components "hoping" one will be the cure. Thats an expensive way to fault find for the owner. Jackie.t mentioned tests were done -- But was not told what types of tests - what tests would be interesting to actually find out. |
wainuitech (129) | ||
| 1223888 | 2011-08-24 00:22:00 | I used to play a fair lot of games on my old HP desktop, which was running a 478 2.2ghz p4, 1.5gb ram and a geforce fx5500, all on a 250 watt no name (or rather, name that sounds like a good brand but isn't) psu. Bestec? HP love using those. Some are OK, some models however have a crappy 5vSB circuit, and when the capacitors in it fail, the 5vSB rail goes up to 15v or more, destroying your motherboard. |
Agent_24 (57) | ||
| 1223889 | 2011-08-24 00:30:00 | Not being rude, but not every thing that fails is due to bad caps. :) Jackie.t mentioned tests were done -- But was not told what types of tests - what tests would be interesting to actually find out. Of course not, I know that. I've replaced open and shorted secondary rectifiers, open startup resistors, bad capacitors in PSUs, and other components in other devices. The thing is that cheap PSUs always use cheap capacitors, and cheap capacitors in stressful applications are likely to fail sooner than later. I would also like to know what these tests were... |
Agent_24 (57) | ||
| 1223890 | 2011-08-24 01:13:00 | Mmm yes you're right that I am not that keen on checking out the PSU myself but can definitely organize someone else to do that, probably in the weekend . As far as those tests are concerned I wonder if it's worth me contacting ExtremePC (where I had it checked last) and find out what they actually did, as it has been running fine since then, LOL . |
jackie.t (16504) | ||
| 1223891 | 2011-08-24 01:31:00 | Bestec? HP love using those . Some are OK, some models however have a crappy 5vSB circuit, and when the capacitors in it fail, the 5vSB rail goes up to 15v or more, destroying your motherboard . If the motherboard is destroyed then more than caps have failed . When filter capacitors fail in an smps, whether shorted, leaky, high impedance or open circuit, the rail voltage generally goes down, not up . If bulging tops are the visible symptom, they are almost always filter caps, that is about all that electrolytics are used for in switch-mode power supplies . Unfiltered switching spikes might then do collateral damage that raised the 5 Volt rail to 15 volts (sounds like a 5 volt regulator failure due to repetitive transient peak-current loading actually) but that would not be directly attributable to the capacitor failure . However, the net result is the same I guess . Cheers Billy 8-{) |
Billy T (70) | ||
| 1223892 | 2011-08-24 03:53:00 | The problem starts with failed capacitors (although not filter capacitors) the two transistor +5Vsb circuits (either BJT or MOS switch) are reliable - but one electrolytic (usually 22uF/50v or 47uF/50v) used on the primary side of the flyback is critical. It eventually dries out, causing an auxiliary secondary-side over-voltage on both the controller power rail, as well as +5Vsb. If it doesn't take out the mobo first, it will take out the PWM controller circuitry and then the mobo. www.badcaps.net I think you'll find it an interesting read. |
Agent_24 (57) | ||
| 1223893 | 2011-08-24 04:58:00 | ........ExtremePC (where I had it checked last) and find out what they actually did, as it has been running fine since then, LOL. Seems wee are all on the wrong bandwagon here?? :clap:clap PC is working OK at the mo... |
1101 (13337) | ||
| 1223894 | 2011-08-24 06:28:00 | On Monday I had a free computer check done elsewhere and this tech has changed a port on the motherboard and suggested that this is the problem! I also called them today and asked what "tests" they did . Checked the Ram Checked the Hard Drive for any bad partitions Checked for any viruses, etc Basic system clean up . Without much computer knowledge on my part (and another language problem) it was difficult to extract much more in the way of information . And yes, it works . . . . . . . . . for now! Sadly, I have had this happen many times before and it never lasts for long, I am kind of just enjoying it while I can! |
jackie.t (16504) | ||
| 1223895 | 2011-08-24 06:33:00 | So one presumes no one checked the Power Supply Unit then? | Snorkbox (15764) | ||
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