TS100 Fix (Sen-Err / overheating) - MOSFET replacement

This video shows how to fix a faulty TS100 soldering iron which immediately heats up the tip after plugging it into the power supply.

Here is the explanation to why some TS100 are failing with shorted MOSFETs. Two important things first:

1. A faulty tip can short out the MOSFETs source and drain pins, which will induce a very high current through it.
2. The current seems to be mostly limited by the power supply, which is often a simple laptop charger with a current limit protection of about 2.1A, which is within the specifications of the original MOSFET, so most of the time you will only need to replace a faulty tip and you're fine.

However, if you use a power supply which can deliver more than 5A, you risk that the maximal current (5A) of the MOSFET is exceeded and you destroy it - when the tip fails. My power supply can deliver up to 10A, more than enough to roast the original MOSFET. I now have a 5A fuse inline with the power cable and the replacement MOSFET can deal with up to 6.9A, so it should be fine even if my tip fails or I put in a shorted one.

Here are some replacement MOSFETs:
HM4953A or CJQ4953 (used in TS100)
SI4925DY (the one I used, with -6.9A)
SI4925DDY (the same as above, but -5A)
SH8J31 (-60V, -4.5A)
IRF7328PbF (-30V, -8A)
IRF9362PbF (-30V, -8A)
AO4801A (-30V, -5A)
any other P-channel dual MOSFET with -30V and at least -5A

Music: Candlepower from Chris Zabriskie