Question New System Build in Old Case Causing Problems

Sep 22, 2023
My system finally died, so I decided to upgrade my system after 12 years, but like an idiot, I used the old case I already had. Put it all together, but it wouldn't boot. Had someone techier tell me that using old cords could be the problem and wreak havoc. Unplugged the 2 old power cords (from PSU to SATA 3.5 internal drives), and the system posted, but looks like I lost my front fans and LED's on the power switch. Wondering if I fried something or if the case is the problem?

As the system is installed in the case, I'm wondering if I should proceed with installing Windows to see if everything works, or if I should just give up on the case, buy a new one, and start all over again?

Further information: I was actually talking about the 2 hard drive power cord from the PSU to the 4 - 3.25 hard drives that were a carryover from the old system. All other power cords from the PSU to the motherboard, CPU were brand new. PSU power cord is brand new out of box. Internal wiring from old case was used for internal cooling fans, audio controller, USB plugs on front of case.

Installation documentation from each component was used, as well as supplemental YouTube videos.

System Specs

CPU: Intel i9-13900K--NEW
MB: Asus ROG Strix Z790-A--NEW
RAM: Corsair 32GB Ven D5 6000 C36--NEW
PSU: Corsair RM850X---NEW
Noctua DH-15 CPU Cooler--NEW
Drives: 4 - 3.5 in Western Digital drives. 6TB (20% full), 4TB (30%), 1TB (45%), 1TB (45%), 320GB (30%) - All Old Drives

Please let me know if that's enough info.

Thanks, Ralston18
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Update your post to include full system hardware specs and OS information.

Include PSU: make, model, wattage, age, condition (original to build, new, refurbished, used)?

Disk drives: make, model, capacity, how full?

I would not expect "old power cords" (from wall outlet to PSU) to cause a problem.

However if you changed PSU's and mixed modular "old" power cords from the original PSU to the new PSU then there could be any number of problems.

What documentation was used when you "Put it all together"?

More information needed.
There's likely no problem with the old case, just the old power cords.

As there is no standard way to wire the PSU end of those cords, using the old cords in a new PSU can easily fry anything attached to those cords even briefly, especially your drives.

The power LED is polarity-sensitive but it's a diode so unlikely to be damaged from wiring it backwards. Try reversing the lead and it may light.


I was actually talking about the 2 hard drive power cord from the PSU to the 4 - 3.25 hard drives that were a carryover from the old system
Yes this is where I would for piece of mind with a OHM meter put the old power supply cable and new power supply cable-------were talking SATA cable----- side by side and trace each pin on SATA side to the other end that plugs into power supply. Does each side match cable to cable or is one cable different where wire inside sleave terminate in different spot before you plug it into power supply.