You really shouldn't. This is a design flaw, worthy of a class action lawsuit comparable to the one Microsoft faced for the Xbox 360 RROD fiasco. With the old ds, the gold contacts would bend and break over time from games being inserted and ejected and such. Nintendo "rectified" the problem by adding a spring to force it into the right place. Pretty stupid on their R&D dept.'s part. Forcing electronics only breaks them over time. The average lifespan of a DS lite is about a year. If you bought your kids their systems at about the same time, that would explain why they both dont work. I recommend ditching the DS. Either invest in PSPs, as they are more versatile, and you can pirate games on them, so you don't have to pay $60 for a game because you can download them on the internet. But if your kids really want to keep the DS, I have a suggestion. My sister has a lite, and has had it since it first came out. If you pay the $75 to get it fixed, it could be cheaper in the long run, as it will never break again if you do what i'm about to tell you, and you'll never pay for another game again. My sister prevented this on her Ds Lite because she never ejects her cartridge. she has something called an R4 chip. Its really easy to use. the R4 is a cartridge that has a slot that can house a micro SD card. You can actually download games to this chip, for free from various places on the internet. And the DS will never break again from wear and tear, because you dont eject the R4 if you want more games, you eject the micro SD from the R4. Shoot me an email at email@example.com
if you want to know more about this. No i do not work for R4, i sincerely believe this course of action will save you the most money. Here is R4s website. Take a look.