Repairing a Water Damaged NuTone IM2003 Master Station

It's All About The Corrosion. . . 

This NuTone IM2003 was delivered to the shop with almost no signs of life.

Initial testing showed that that the Master Station had power, but it did little more that turn on its power LED.

Upon inspection I found fairly severe water damage on both side of the main circuit board.

The red arrows point to the typical corrosion and some rust that had formed.  The blue arrow points to what looks like some light corrosion around the power switch.  What's hidden under the switch is a completely different story, the corrosion was so bad that it had eaten away one of the leads on the switch.

On the bottom there was more corrosion and many solder connections had turned to dust and failed.

The red arrow point to corrosion that has formed between the leads of the amplifier IC, the blue arrow points to rust on the board, the green arrow point to where the corrosion has turned the solder to dust and underneath the copper solder pads have been somewhat eaten away.

The blue arrow points to the the most serious damage to the main circuit board.  The copper trace on the other side of the interconnect wire that protrudes through the board had been eaten away, breaking the connection on either side of the wire.  The red wires are temporary, just enough to complete the circuit for more testing.

Here is the completed repair to the damaged trace.  The temporary red wires have been removed, the solder mask was scraped off and a bridge lead was soldered across the break.  Once this repaired was tested and know to be successful, some new solder mask was applied to cover this area of the board.

Due to the amount of damage to this end of there board, I removed all of the effected components and replaced them after cleaning the board.  This is the only way to insure that the problem won't reoccure in the future.

 See the Complete Video of this NuTone IM2003

https://www.youtube.com/channel/UCcMN_sDzaDThDYRBb2Qcahw