The closest thing to gambling I do is buying and repairing broken GBCs on EBay. I'm very confident with electronics repair, and have often taken a risk on a console that doesn't turn on or has screen damage, or bought one that's explicitly for parts. These are some things I look out for and how I judge how damaged I suspect a given GBC might be. > [!NOTE] **TL;DR** > Try to find GBCs from regular people selling them because they didn't bother to clean off the battery corrosion. After that, _caveat emptor_. # Best Case Scenarios — Superficial Damage Your best case scenario is that the console works perfectly and needs either only superficial repair, or replacement of a part you were already going to replace. ## Battery Terminal Corrosion The easiest superficial damage to fix is battery terminal corrosion. This is extremely common. Anybody who doesn't know about this being a common issue — especially if the seller is a regular person — probably has an otherwise perfect GBC. > [!TIP] What to look for > * Blue grit on battery terminals > * An otherwise good-condition console with no other visible damage that doesn't turn on # Mixed-Case Scenarios — Replaceable Damage These are all issues that could make great contenders for an overhaul, especially if the issues are with the part you're going to replace. However, these issues can also mask other harder-to-fix problems. Some of these issues will require some soldering experience to replace. ## Burned Screen Some GBCs left in the sun develop a distinctive burn pattern. Sometimes this means this console is a great candidate for a new screen. ## Quiet or No Sound This can _sometimes_ be as easy as replacing the speaker or the volume pot. # Worst-Case Scenarios — Risky or Hard-To-Fix Damage ## Doesn't Turn On This is probably still just corrosion, but if I can _see the terminals in the listing and they aren't corroded_ this might be more complex. The next-best thing is that this is just an issue with the power switch, but barring that it's likely something far more sinister. ## Some Buttons Don't Work This means there's some amount of corrosion on the pads or damage to the traces on the motherboard that go to the pads of the controls. Cleaning the pads is trivial, but repairing traces can be much more complex and requires advanced repair _if_ the damage isn't too bad. ## No Video This is probably either blown capacitors or, in my experience, something wrong with the DC-to-DC board that provides power to the video board. When I ran into this, I found that sourcing a new DC-to-DC board (either a replacement or a third-party-one) was about the same price as just spinning the wheel on another. # What to Avoid I look mostly for consoles that look well-played, but in otherwise good condition. If it's got serious damage to the case, clear water damage, or _extreme_ battery corrosion, I'll generally pass it up. # Picking Sellers Buying from regular people is usually the best way to find GBCs that are easy to fix. Accounts that specialize in retro gaming or electronics will usually only be selling ones that they've already tried to fix and couldn't. This also goes for listings that have the device opened up. If they own a tri-wing screwdriver and don't mind opening it up, they're not going to let an easy-to fix one slip by. # Prices I like to pay anything between $30 and $50 for a GBC, scaled to how hard I'll have to work on it.