I want to repair the power suply on the above printer...

Consumer grade printers aren't exactly easy to service, and they are generally more expensive to repair then the cost of replacing the whole printer. While you can probably find the repair parts, they tend to be expensive. The cost of OEM drums leads to people dumping these printers over consumables, so my advice is to get one of these printers and reuse your current drum and toner (reset the drum counter if you need to, but see my warning in the caveats listed). Depending on the life of the toner the printer came with, you may even have extra toner on hand. The drum may still be usable as well, but many of these printers are so close to 0% remaining it isn't worth trying to salvage this. It's your call what you do with the drum it came with depending on the remaining percentage.

However, this does come with a few major caveats:

• The drum life reported will not be accurate on the "new" printer since you are installing a used drum and it isn't brand new. Don't rely on the counter; if the image quality is bad it's time to purchase a new drum and reset the counter. The drum life counter will become accurate once you reset the drum life to 100% and install a brand new drum. If you can run on 0%, I'd suggest letting it stay that way until you buy a drum that's new in the box.
• The fuser life (if considered a consumable) will no longer be accurate if you move your old one over (but will remain accurate if you don't change it). Again, rely on the output and replace it with brand new parts to restore accuracy.
• Do NOT move the formatter board. The page count, other corresponding data and serial number will not match.

If you do choose to repair the printer, you will need to see if it's a bad power supply or HV PCB, as these are likely to be the problem. More then likely it's a power supply fault, but you should also inspect the High Voltage PCB just to be sure. If it's a fault that is obvious, then it may be worth attempting the repair. If it's difficult or expensive I'd just recommend getting one of the many printers with consumed drums and then moving your drum and toner set to the newly acquired printer. You can get any printer that uses the same drum or another HL-2170. Of course, the old printer should be recycled or given to someone who can make use of the remaining parts. You can find the service manual here.

If you don't have a need to maintain compatibility with your old drum and toner find a printer that meets your needs that is on sale. Since the odds of the old toner and drum being compatible are low, I wouldn't look for this specifically.