We are so sorry for the problem.
The oil leak issue comes from the thermal pads some ASI cameras used. Some of them have higher oil content so after long-time use, the oil infiltrates into the gaps of sensor and board, and even the sensor surfaces. It needs us to do deep cleaning work and replace the pads to throughly avoid the issue occurring again in the future.
For all the ZWO customers suffering from the problem, we offer the "Replacement or Free repair" service.
1) You can contact us and directly send the camera to ZWO or the dealer where you bought the camera to get a new one. All the expenses incurred in transit will be met by ZWO (Just remember to keep your invoices) Also, we offer free home access service if you live in the USA and have the need of sending your camera back to ZWO.
Please notice that replacement requires your old camera to still be under 2-year warranty.
2) You can also send your camera with oil leak issue to the ZWO official maintenance points to get free repair service. We now have 3 such points in the USA, Germany and Japan. The repair service includes deep oil cleaning, thermal pads replacing, and sensor tilt resetting.
We provide lifetime warranty if your camera happens to have this issue.
3) The "Replacement or Free repair" service not only applies to the ASI2600 camera, also to other modules with the problem.
Please let us know if there is anything else we can help!