Corsair CX450 Psu issue

[vidhubhushan]

Corsair cx450 is used for this system.
Amd ryzen 5 3400g
Asrock b450 pro 4
256gb Mx500
500gb bx500
2tb wd blue
4tb wd blue
Corsair carbide spic delta

It worked without any problem since January 2020.
A month back apc bx600i stopped working so I changed my livfast 850va inverter to ups mode and connected the computer to power outlet directly.
2 days Back it stopped working. I tried the wire test and noticed that the psu is not working so yesterday I got it checked in the local market as the 5 year warranty is over.
Psu got repaired for 800 and it worked yesterday. Today the situation is the same I.e. it is not working again. It appears the psu is the issue.
I will get it checked tomorrow but I am thinking of getting it replaced and keep it for backup. As far as I can check, this model is not available in the market right now. So I am thinking of cx550 but noticed that there is a cx550m is also there. As far as I can remember, cv and vs psu are inferior to cx series.
Asus TUF Gaming 550B 550 Watt 80 Plus Bronze SMPS too looks ok.
Which one I should go for? There is no plan to add any GPU.
Also I will get the ups repaired tomorrow; most probably it is it's battery issue.

 

[patkim]

cx550m (m generally stands for modular)
Few years ago when I was building my system, I came across tech specs on Corsair site (looks like they have removed that info) that VS (Value Series) operates optimum only at 30 Deg C and it performances gradually decreases as the temps rise but CX series is resilient to operate optimum at even 40 Deg C.

So CX is in fact step-up from VS series. So CX is anytime better than VS.

However personally I am using VS450 for last 5 years (Only low-end GPUs in my system) and it has worked well so far. Now I might go for a brand new PSU anyhow even if this one is working fine.

 

[vidhubhushan]

Something strange happened. I took it to the local shop. It got switched on immediately. He switched it off and on and it worked.
He said that it must be the power cable.
I took it back. Used a new cable but now again it is dead.
Tried it with new apc ups, then directly with power outlet but nothing happening.
Monitor is on with the same points.
What could be the reason?

 

[patkim]

Was the load connected when PSU turned on at the repair shop or was it just a paperclip test?
PSU can turn itself on in a paperclip test but may fail to turn on a load if it's faulty.

Instead of just PSU, if possible take your PC to a repair shop and ask them to do troubleshooting.

 

[vidhubhushan]

He connected a power cable to the computer and it was switched on, display was there windows loaded. It was shutdown and then switched on with the power button and it worked again.
In fact I was speechless as it happened to me for the first time. He asked what he should do as it is all right. He asked me to change the power cable as that must be faulty.
Right now I tried 2 power cables, on ups and directly on the power outlet but it is dead.
Tried an old smps with the same power cable and it worked with wire. Unfortunately it can't be used to test the system as it is ancient and doesn't have necessary connector for cpu. I'll test another one borrowed from someone tomorrow.

 

[patkim]

Try connecting your PC to some other power outlet in another room and test again.
Also if there's a 15A point try connecting to that one too and check again.

 

[vidhubhushan]

this sure is some ghost issue. i connected it back, just the 24pin and mb connector and it got switched on, showed bios. i connected everything else and it loaded windows. i am typing this message on the same computer.

 

[patkim]

Either there was a lurking variable present that we don't know (like connections, dirty power or even ESD) or may be your system is experiencing intermittent failures.

 

[vidhubhushan]

today morning i switched it on and it worked for some 4-5 hours. i went out at around 3pm and came back at around 8.35pm. it didn't start then. i left it and tried it around 9.22. it started again and working right now.
i noticed one thing - when it starts after this dead episode, it shows an incorrect time. cmos battery is new, installed just a month back. is this something related to motherboard?
@whitestar_999 @nac @omega44-xt @SaiyanGoku

 

[nac]

Remove all the hardware and assemble again but only minimal components - CPU, MB, 1 memory stick, 1 SSD/HDD, PSU. Reset BIOS to default and run. See if you're still facing any issue with this setup.
Did you get a PSU or still using the repaired one? If you can borrow one (good unit without issue) for testing before buying a new one, try that.
If you're buying new one, any bronze rated from good brand is fine and good. See if this PSU tier listing is of any help.
docs DOT google DOT com/spreadsheets/d/1akCHL7Vhzk_EhrpIGkz8zTEvYfLDcaSpZRB6Xt6JWkc/edit?gid=1719706335#gid=1719706335

 

[vidhubhushan]

Remove all the hardware and assemble again but only minimal components - CPU, MB, 1 memory stick, 1 SSD/HDD, PSU. Reset BIOS to default and run. See if you're still facing any issue with this setup.
Did you get a PSU or still using the repaired one? If you can borrow one (good unit without issue) for testing before buying a new one, try that.
If you're buying new one, any bronze rated from good brand is fine and good. See if this PSU tier listing is of any help.
docs DOT google DOT com/spreadsheets/d/1akCHL7Vhzk_EhrpIGkz8zTEvYfLDcaSpZRB6Xt6JWkc/edit?gid=1719706335#gid=1719706335

thanks. i will try / check if it misbehaves. right now it is working perfectly fine, just like yesterday. i checked in the local market and was going to buy a corsair cx550 for 3850 but it worked in the shop so i didn't buy. i asked someone for a psu. unfortunately his brother now handles all this and is mainly selling cctv so he gave my sister a cctv smps. since it started working i didn't ask and even told another local shop person i don't need to check. now i will ask someone tomorrow and check when it misbehaves.

 

[vidhubhushan]

i checked it till now. results are -
it got started after some 20-25 minutes.

checked and found out that something similar has happened with some. someone said it worked when he left the switched off ups plugged to mains. i tried that day before yesterday night.
but even when i left the switched off ups plugged in, it didn't sttart yesterday morning. after some time i checked but the smps failed the wire test.
after some time i removed the cmos battery for some time and later inserted it. nothing happened immediately.

iirc after some time it started on its own and showed the cmos screen. bios was reset so i edited it and then connected ssd & hdd power cables. it worked then.
around 10.30pm, i switched it off and switched off ups mains as well.

today morning, it started immediately but showed an incorrect time - 12.47AM, 09/08/2025.

i am unable to understand this time change thing. i have changed the cmos battery just a month back, on 3rd july. it was working fine since then, no issues in time.
i was busy so i couldn't get a spare psu from anyone. will try on monday and then check when mine doesn't work, does the spare one makes the system work.

 

[vidhubhushan]

It's not getting started since yesterday. Today I connected a digital watch to front usb port and it is getting charged. Only both power connectors are connected to the motherboard and all other power cables are not connected still it is not getting started. Watch is getting charged.

 

[nac]

Still trying with your PSU?

 

[vidhubhushan]

Still trying with your PSU?

Yes.
Got a corsair vs350 from someone. Checked with just motherboard connections. Same condition. Watch is getting charged but system is not getting switched on.
So now it can be motherboard or cpu which means I need to decide on that. I was thinking of getting a gigabyte b550 and if it is cpu then something better than 3400g.

 

[nac]

Yes.
Got a corsair vs350 from someone. Checked with just motherboard connections. Same condition. Watch is getting charged but system is not getting switched on.
So now it can be motherboard or cpu which means I need to decide on that. I was thinking of getting a gigabyte b550 and if it is cpu then something better than 3400g.

What do you mean by "just motherboard"? I am assuming CPU, Fan, RAM were connected at least.
By getting a B550, you mean buying a new one, better take it to service centre. They can figure out if it's motherboard or CPU. They may even have compatible CPU/Motherboard to test if needed.

 

[vidhubhushan]

What do you mean by "just motherboard"? I am assuming CPU, Fan, RAM were connected at least.
By getting a B550, you mean buying a new one, better take it to service centre. They can figure out if it's motherboard or CPU. They may even have compatible CPU/Motherboard to test if needed.

Yes all those were connected, no ssd or hdd was connected.
Yes, a new one if it is cpu or motherboard.
Compuworld has service center of asrock as per their website but they said they don't service computer things so it is down to local market. Also the motherboard was purchased on 18/12/2019 and psu, cpu on 15/01/2020 both oow now.

 

[vidhubhushan]

Took it to the same local place. It started without any problem. It was shutdown and restarted multiple times.
Brought it back. Checked it with power cable and direct inverter line in another room. It started.
I connected cables and it is not working again.

 

[nac]

Something is acting up, couldn't pin point what.

I don't think it's the cable you connected which made it not working.

You have take the system to the repair shop 2-3 times so far. What they are saying after you report that it's booting sometime and it's not booting sometime?

Move everything out of the cabinet. If CPU/heatsink/fan was recently removed, cleaned and reapplied thermal paste, that's fine. Else remove/clean and reapply thermal paste. If you have blow dryer, blow some hot air on the motherboard before starting. Sometimes old and/or dying motherboard act up during winter/monsoon season, hot air may help. Does your motherboard has any debug LED or something?