VOGONS


First post, by Baoran

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I have a 7 year old atx seasonic power supply that gives me sometimes strange readings when using multimeter to measure voltage. I always thought seasonic power supplies were good and 7 years would be nothing to them.
Basically only thing I have been able to replicate is that when the power supply has been without a power for a while (without power cable connected to it) when I connect the power cable and I turn it on I get voltages between 14V and 15V when measuring the 12V output using multimeter. It seems like the voltage reading gradually decreases after being turned on until it reaches about 12.17V and then the reading stays there stable. Main thing that in a bios that shows pc health status it shows 12V voltage to be around 12.05V during the whole time when my multimeter is showing voltages between 14V and 15V. Mostly the reading starts around 14.5V when a computer is first turned on after having power cable disconnected.
I have some questions.

1. Could this be normal behaviour from a power supply?
2. What could be wrong with the power supply that could cause this kind of behaviour if there is a problem with it?
3. Why would bios and multimeter readings be so different? If it is bios showing wrong readings, it makes me feel like using bios to try figure out when power supply is going bad is pointless.

Reply 1 of 13, by pentiumspeed

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This getting better with heat is symptom of dying capacitors starting to show. When this happens is there is a short window of time between good capacitor and dried up capacitor where slightly good capacitor is no good when cool but get better with heat always, the heat be it be internal or external or both, changes the conductivity of the electrolyte "fluid" and they get better when warmer. Electrolyte is what helps to electrically connect to the porous surface and increase the capacitance by vinte of surface area and one side of foil is insulated provides electrons to separate and build up provides charge to discharge and absorb to smooth out the voltage. One component of the electrolyte is water or similar is slowly outgassing with age, hence the hours rating of both storage, heat, and in use.

Very common in my repair field.

Do not use it again till you get recapped the voltage feedback circuit. A circuit that monitors the outputs and dynamically stabilizes the voltage based on load.

Cheers,

Great Northern aka Canada.

Reply 2 of 13, by Baoran

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pentiumspeed wrote on 2020-11-01, 22:27:
This getting better with heat is symptom of dying capacitors starting to show. When this happens is there is a short window o […]
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This getting better with heat is symptom of dying capacitors starting to show. When this happens is there is a short window of time between good capacitor and dried up capacitor where slightly good capacitor is no good when cool but get better with heat always, the heat be it be internal or external or both, changes the conductivity of the electrolyte "fluid" and they get better when warmer. Electrolyte is what helps to electrically connect to the porous surface and increase the capacitance by vinte of surface area and one side of foil is insulated provides electrons to separate and build up provides charge to discharge and absorb to smooth out the voltage. One component of the electrolyte is water or similar is slowly outgassing with age, hence the hours rating of both storage, heat, and in use.

Very common in my repair field.

Do not use it again till you get recapped the voltage feedback circuit. A circuit that monitors the outputs and dynamically stabilizes the voltage based on load.

Cheers,

The power supply actually has 7 year warranty that ends in about 10 days if I calculated correctly. That is why I thought it would be going bad because of the age would be strange.
Wouldn't seasonic power supplies like this have overvoltage protection of some kind also?

Reply 3 of 13, by Horun

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Baoran wrote on 2020-11-01, 22:33:
pentiumspeed wrote on 2020-11-01, 22:27:
This getting better with heat is symptom of dying capacitors starting to show. When this happens is there is a short window o […]
Show full quote

This getting better with heat is symptom of dying capacitors starting to show. When this happens is there is a short window of time between good capacitor and dried up capacitor where slightly good capacitor is no good when cool but get better with heat always, the heat be it be internal or external or both, changes the conductivity of the electrolyte "fluid" and they get better when warmer. Electrolyte is what helps to electrically connect to the porous surface and increase the capacitance by vinte of surface area and one side of foil is insulated provides electrons to separate and build up provides charge to discharge and absorb to smooth out the voltage. One component of the electrolyte is water or similar is slowly outgassing with age, hence the hours rating of both storage, heat, and in use.

Very common in my repair field.

Do not use it again till you get recapped the voltage feedback circuit. A circuit that monitors the outputs and dynamically stabilizes the voltage based on load.

Cheers,

The power supply actually has 7 year warranty that ends in about 10 days if I calculated correctly. That is why I thought it would be going bad because of the age would be strange.
Wouldn't seasonic power supplies like this have overvoltage protection of some kind also?

Yes and that is what he is referring too. The circuit that handles OVP, OCP, SSP, etc is a small part of the PSU and has it's own IC, caps, etc.
If those specific caps start to degrade then the OVP, OCP, etc no longer function as intended.
It is also possible that some other main output caps are failing but due to the volts being to high that is unlikely, bad out caps usually result in too low voltage...

Hate posting a reply and have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. 🤣 Second computer a 286 12Mhz with real IDE drive ! After that came 386, 486, Pentium, P.Pro and everything after....

Reply 4 of 13, by wiretap

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The motherboard sensors don't sample the voltage at a high rate. With ripple, it could be periodically sampling just at the right interval of the sine wave to where it shows good. The real question is, what is the ripple of the power supply outputs under load? You have to use a true rms multimeter measuring AC or an oscilloscope to get an accurate reading.

Circuit Board Repair Manuals
Turbo Display Project
Dual Socket 8 Project

Reply 5 of 13, by Baoran

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I have one more question. Is there any chance that some other part in a computer could cause high voltage readings like that? Perhaps a faulty video card or something similar with external power connector(s)?

Reply 6 of 13, by pentiumspeed

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No again, the power supply is doing that. Motherboard is *not* the one that plays with power supply's voltage, the motherboard actually *requires* regulated voltages *from* the power supply which power supply is responsible for and must keep voltages within narrow range when current varies.

Cheers,

Great Northern aka Canada.

Reply 7 of 13, by Baoran

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pentiumspeed wrote on 2020-11-02, 15:10:

No again, the power supply is doing that. Motherboard is *not* the one that plays with power supply's voltage, the motherboard actually *requires* regulated voltages *from* the power supply which power supply is responsible for and must keep voltages within narrow range when current varies.

Cheers,

I guess I am just hoping. It is in a computer that I really need running and I ordered a new seasonic power supply but for some reason power supplies are really not available in my country right now. They estimate getting the power supply I ordered takes over 2 months. I don't know what other options I have except to keep power cable connected to the pc that I won't get those high voltages and hope the things stay ok for those 2 months.

Reply 8 of 13, by Horun

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Baoran wrote on 2020-11-02, 20:31:
pentiumspeed wrote on 2020-11-02, 15:10:

No again, the power supply is doing that. Motherboard is *not* the one that plays with power supply's voltage, the motherboard actually *requires* regulated voltages *from* the power supply which power supply is responsible for and must keep voltages within narrow range when current varies.
Cheers,

I guess I am just hoping. It is in a computer that I really need running and I ordered a new seasonic power supply but for some reason power supplies are really not available in my country right now. They estimate getting the power supply I ordered takes over 2 months. I don't know what other options I have except to keep power cable connected to the pc that I won't get those high voltages and hope the things stay ok for those 2 months.

Curious what type of system is this and what is the wattage of that 7 year old Seasonic ? Also curious why you disconnect the power cable from it ?
I rarely unplug my daily use computers, maybe once in a year, two or three years. Is there a reason you unplug your needed one from the power ?
Have you looked into other brands of PSU like Corsair, Antec, etc ? They may be easier to get. Yes Seasonic does build some good PSU but like all companies some years and models are not as good as others. Even Seasonic has some not-so-good models
I prefer Antec, Corsair and EVGA named PSU for newer computers.... just rambling.

Hate posting a reply and have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. 🤣 Second computer a 286 12Mhz with real IDE drive ! After that came 386, 486, Pentium, P.Pro and everything after....

Reply 9 of 13, by TheMobRules

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Keep in mind that from those companies you mentioned, Seasonic is the only one that actually manufactures power supplies, in fact Antec, Corsair and EVGA had (and may still have) units built by Seasonic for some of their models.

The SS Focus, for instance, is a very good series of PSUs. Of course, they also have lower end models, but so do the others.

Reply 10 of 13, by Baoran

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Horun wrote on 2020-11-03, 04:35:
Curious what type of system is this and what is the wattage of that 7 year old Seasonic ? Also curious why you disconnect the po […]
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Baoran wrote on 2020-11-02, 20:31:
pentiumspeed wrote on 2020-11-02, 15:10:

No again, the power supply is doing that. Motherboard is *not* the one that plays with power supply's voltage, the motherboard actually *requires* regulated voltages *from* the power supply which power supply is responsible for and must keep voltages within narrow range when current varies.
Cheers,

I guess I am just hoping. It is in a computer that I really need running and I ordered a new seasonic power supply but for some reason power supplies are really not available in my country right now. They estimate getting the power supply I ordered takes over 2 months. I don't know what other options I have except to keep power cable connected to the pc that I won't get those high voltages and hope the things stay ok for those 2 months.

Curious what type of system is this and what is the wattage of that 7 year old Seasonic ? Also curious why you disconnect the power cable from it ?
I rarely unplug my daily use computers, maybe once in a year, two or three years. Is there a reason you unplug your needed one from the power ?
Have you looked into other brands of PSU like Corsair, Antec, etc ? They may be easier to get. Yes Seasonic does build some good PSU but like all companies some years and models are not as good as others. Even Seasonic has some not-so-good models
I prefer Antec, Corsair and EVGA named PSU for newer computers.... just rambling.

I didn't bring up system because it does match the topic of this forum, but I thought talking about 7 year old power supply might be accepted. Basically it is my main gaming system for modern games. The power supply is Seasonic P-860 XP2 from 2013 and basically the system became extremely unstable when I upgraded the video card to one of the new nvidia ones that were released this year. Randomly rebooting and that happened especially soon after turning on the system more than when the system had been running for a bit. Also any video software like mpv that uses gpu acceleration is crashing often and watching youtube too. Basically that is what caused me to start measuring voltages from pci-e power cables coming from psu to the video card. First they seemed to be ok because I was measuring them after system had been running for a while but then I happened to measure them soon after connecting power cable to system and I saw the voltages of up to 14.51V. I have already switched back to my old graphics card and system is stable for now at least. Now I am wondering if I should RMA the video card or not because there is a chance that the the problems could be due to video card using more power and the power supply going bad instead of having gotten a bad video card.

Reply 12 of 13, by Horun

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TheMobRules wrote on 2020-11-03, 04:52:

Keep in mind that from those companies you mentioned, Seasonic is the only one that actually manufactures power supplies, in fact Antec, Corsair and EVGA had (and may still have) units built by Seasonic for some of their models.

The SS Focus, for instance, is a very good series of PSUs. Of course, they also have lower end models, but so do the others.

Yes they do make most of many named brands but they are under contract to build them to the contract specs, they also build ones with their own name and some are very sub par compared to the ones contracted.
Sure the some series are good but they also have other series with as little as 5 year warranty, and then you have to consider OP is talking about a PSU built in 2012-2013.....
Delta does same thing, most Delta are exceptional PSU but some are not (some of the Dell contracted are great but some of Delta's own AND contracted are somewhat subpar).

Baoran wrote on 2020-11-03, 05:26:

I didn't bring up system because it does match the topic of this forum, but I thought talking about 7 year old power supply might be accepted. Basically it is my main gaming system for modern games. The power supply is Seasonic P-860 XP2 from 2013 and basically the system became extremely unstable when I upgraded the video card to one of the new nvidia ones that were released this year.

Ahh thanks ! My guess is that it is reaching it's end of life span if you have used it daily for near 7 years. There is no way a company knows how long a specific unit will last but can estimate and given a 7 year warranty they figure most will last 10 years on average.
Your particular unit just happens to fail in less than that but still under warranty. Hope you put in a RMA. But considering everything you actually got a good long life out of it.

Hate posting a reply and have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. 🤣 Second computer a 286 12Mhz with real IDE drive ! After that came 386, 486, Pentium, P.Pro and everything after....

Reply 13 of 13, by Baoran

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Horun wrote on 2020-11-04, 03:26:
Yes they do make most of many named brands but they are under contract to build them to the contract specs, they also build ones […]
Show full quote
TheMobRules wrote on 2020-11-03, 04:52:

Keep in mind that from those companies you mentioned, Seasonic is the only one that actually manufactures power supplies, in fact Antec, Corsair and EVGA had (and may still have) units built by Seasonic for some of their models.

The SS Focus, for instance, is a very good series of PSUs. Of course, they also have lower end models, but so do the others.

Yes they do make most of many named brands but they are under contract to build them to the contract specs, they also build ones with their own name and some are very sub par compared to the ones contracted.
Sure the some series are good but they also have other series with as little as 5 year warranty, and then you have to consider OP is talking about a PSU built in 2012-2013.....
Delta does same thing, most Delta are exceptional PSU but some are not (some of the Dell contracted are great but some of Delta's own AND contracted are somewhat subpar).

Baoran wrote on 2020-11-03, 05:26:

I didn't bring up system because it does match the topic of this forum, but I thought talking about 7 year old power supply might be accepted. Basically it is my main gaming system for modern games. The power supply is Seasonic P-860 XP2 from 2013 and basically the system became extremely unstable when I upgraded the video card to one of the new nvidia ones that were released this year.

Ahh thanks ! My guess is that it is reaching it's end of life span if you have used it daily for near 7 years. There is no way a company knows how long a specific unit will last but can estimate and given a 7 year warranty they figure most will last 10 years on average.
Your particular unit just happens to fail in less than that but still under warranty. Hope you put in a RMA. But considering everything you actually got a good long life out of it.

Thanks. The new power supply I ordered is also seasonic. Model TX-1000 with 12 year warranty this time. I don't really care about warranty of the old psu. I just need the old psu to hold on a little longer that I can keep the system running until I get the new one. I used to have the system running all the time, but nowadays I turn it off for the night, so the old psu must have been turned on for around 50k hours total during the 7 years.