Is this PSU good to transfer over?

[varis]

So I had this old system with high quality Enermax PSU. Recently it started to refuse to go to BIOS, some troubleshooting and on Asus forum they suggested it might be the CPU. But I wonder how much I can trust that assumption, could it still be the PSU that is broken and is giving bad electricity to the system? In other words, would it be a smart idea to move the PSU to the new build without testing it with the old build first?

Old system http://www.tomshardware.co.uk/forum/300498-31-building-range-gaming-quiet-intel

Aged 6 years

Antec Sonata III (no PSU, comes with their 120mm Tricool)
Noctua NF-S12B FLX 120mm
Enermax Pro87+ 500W
Gigabyte Windforce Radeon 6850
Core i3 540
Cooler Master Hyper 212 Plus
Kingston Valueram 4GB (2x2Gt) 1333MHz DDR3, CL9
Asus P7H55
Samsung SH-S223L/BEBE DVD-RW
OCZ Vertex 2 - 60GB 2.5" SSD SATA II
80 GB HDD (Samsung Spinpoint, old)
Soundblaster 2 Audigy ZS
Arctic Cooling MX-3 Premium Thermal Compound
Microsoft Windows 7 Home Premium Edition UK Retail (will install 64bit)
ArchLinux

New system http://www.tomshardware.co.uk/answers/id-3406839/decisions-mid-range-intel-gaming-low-noise.html

Parts are being ordered

Fractal Design Define R5 Blackout Edition(?), windowed
(re-use) Enermax Pro87+ 500W
(re-use) Gigabyte Windforce Radeon 6850 <will be upgraded, GTX 1060/1070 or low-end AMD Vega ?>
i5-7600K
Cooler Master Hyper 212 Evo
Corsair Vengeance LPX DDR4 2400 MHz 16 Gt (2 x 8 Gt)
14-16-16-31 1.2V (or 2800 MHz CL 14-16-16-36)
OR Corsair Vengeance LED DDR4 3000 MHz 16 Gt (2 x 8 Gt) 15-17-17-35 1.35V

Asus Prime Z270-K
(re-use) Samsung SH-S223L/BEBE DVD-RW
(re-use) Samsung 840 EVO 256GB
AND Samsung 960 EVO SSD 250 Gt M.2
<HDD, see below> (re-use)
(re-use) Soundblaster 2 Audigy ZS
(re-use) Microsoft Windows 7 Home Premium Edition UK Retail <update to win10>
<Linux>

The practical consequence is which kind of PSU I'd need to buy. For the old it would be sufficient to get a base quality 400W one as it draws power only up to 200W or so previously, and spec won't jump that much when new hardware is substituted to make it functional again. The new system will have a stronger GPU at least so power draw could be around 300W - I'd maybe go with a 500-550W PSU to have some room to spare, it should be a high quality 80 Plus Gold certified one.

Which brands are considered kosher by discerning PSU enthusiasts? Seasonic, Cooler Master, Fractal Design? Which Corsair series are safe?

(Is the list http://www.tomshardware.co.uk/forum/id-2547993/psu-tier-list.html?_ga=2.1310329.975142854.1494672587-1419801324.1494002924 still up to date - could at least browse that for the best brand names?)

 

[jpe1701]

The corsair rmx series is great and also look at the Evga g2 or G3.

 

[varis]

Would you say a PSU has an expected lifespan of more like a decade or two decades, or more, assuming a typical usage of a few hours every day? (Though when the system is bumped down to 2nd line of service, the usage drops dramatically.)