The reasons:
Over time the stuff (dielectric) inside (electrolytic some types of) capacitors may not maintain their stated value. This can be because of hard use, low quality power source, or sometimes just age.
I'll be recapping my power supply as preventive maintenance.
It is possible to create your own kit, the actual capacitors and their values are very standard. In most cases it's easier to purchase one for $4-6. Many companies will offer both a Power Supply kit and a Console motherboard kit. With the standard cost of shipping consider purchasing both.
There are multiple OEM Power Supply designs! All are NUS-002 (USA).
The engraved line is probably a serial number.
The LSEP and Zebra designs are very different, different IC counts, clearly different PCB layouts, zebra uses steal shielding and the LSEP appears to be copper. The ones I've checked all have the same output specs.
The recap kit I purchased specifies the Zebra so that is the unit I'll be using.
References: