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.