Super Famicom: bent pins in the 62-pin slot after a cartridge was forced in

What a backwards cartridge does

A cartridge pushed in backwards puts 5 V where ground should be. Most of the time the console's protection is adequate and nothing dies, but the pins in the slot take the mechanical damage. Two or three pins per side bend flat and either short to their neighbours or stop making contact at all.

The symptom is usually a console that no longer boots any cartridge, which makes owners think the console is dead. It is almost never dead; it is a slot with three bent pins.

Finding the bent pins

Look into the slot with a bright angled light and a magnifier. Bent pins lie flatter than the rest and are usually at one end. On a Super Famicom the slot is easy to see because the cartridge door opens wide.

Then check whether any pins are shorted to each other with a continuity meter. Adjacent pins that read shorted are touching, and that is the fault that stops the console booting. A pin that has simply lost contact stops one data line and produces corrupted graphics rather than a dead console.

1. Inspect the slot under bright angled light at 10x. Note every pin that is flatter than its neighbours.
2. Map the damage: which pins are bent, which are shorted to each other, and which have lost contact.
3. Check for a short between adjacent pins with a continuity meter, working along the slot.
4. Check that the 5 V and ground pins are not shorted to each other. If they are, stop and resolve that before applying power.
5. Look for any sign of heat damage near the slot. A sustained short will discolour the board.

Straightening pins without breaking them

A bent pin on this connector is thin phosphor bronze and work-hardens quickly. You get two or three attempts before it snaps. Use a fine pair of tweezers or a sewing needle and bend it a little at a time, checking with a straight edge against the neighbouring pins after each adjustment.

If a pin does snap, the slot has to be replaced. That is a 62-pin desolder job, which is manageable but takes an hour. Do not try to solder a broken pin back on; it will not take the spring load and it will fail the next time a cartridge goes in.

1. Straighten each bent pin a little at a time with fine tweezers, checking against a neighbouring pin as a reference.
2. After each adjustment, re-check for shorts between the pin you moved and its neighbours.
3. Test the console with a cartridge before reassembling. It is much easier to make a second adjustment with the board out.
4. If a pin snaps, replace the whole slot: desolder 62 pins with a pump and braid, working in rows.
5. Clean the slot contacts with isopropyl alcohol after the repair and apply a small amount of contact conditioner.
6. Test with three cartridges, including one with a thick PCB, and confirm all three boot reliably.