Triac Replacement for CSI853B units

In our batch of CSI853B units from earlier this year Feb 2019, we’ve determined that the triac used in the devices is insufficient for regulation of the AC current regulation to the heating plate. After much discussion with the vendor, they’ve recommended to change the BTA16 to the BTA12. Now, I personally have no idea why this fixes the issue, but in their own testing, and our testing, it does.

The issue is as follows; as the triac heats up, the triac’s ability to regulate AC current will eventually reach it’s breakdown temperature, at which point the triac has zero ability to regulate the current going to the heating plate. This is most likely caused from the Vf of the triac, and therefore the triac is trying to dissipate too much heat. This means, once this event takes place, any temp you set the heating plate to will be irrelevant. Even if you shut the switch off, it will do nothing, as there is nothing to control the heating plate anymore. The only way to shut the device off is to switch the back switch, or unplug the unit itself.

To replace the old BTA16 triac with the new BTA12 and fix the issue, you need only to desolder the previous triac, and resolder the new one. Very easy to do. First remove the screws from the unit. The picture below is the CSI853B+ unit, but the screws are in the same placement for each of the CSI853B series of units.

Next, desolder the BTA16 triac.

In this picture, the triac is just behind this heatsink. You will always know which triac controls the heating plate, by tracing the heating plate’s wires to the triac. On this board, the capacitor is also blown, so if yours is like the above picture, make sure to replace it as well. Once you replaced the parts, put the device back together, and you’re finished.