The NCE PowerHouse Pro is a combined 5 amp booster and command station and I bought this unit second-hand from a modeller’s widow. When it arrived I found that one of the output MOSFETs wasn’t working, I replaced it with no improvement then traced the fault back to the MOSFET driver IC. After I replaced that the unit gave me several years service until I started building my new layout.
Whilst test running my new trackwork, I ran a loco into a turnout that wasn’t switched correctly and shorted out the booster. It cut out correctly but kept on retrying whilst I investigated what was happening – my initial thought was dirty track so I didn’t remove the short quickly enough and the booster died again. The NCE booster gives only a visual indication on cutout and I couldn’t see that from the other end of the layout. Upon investigation, I found two other driver ICs had died in a very convincing way.
I decided at this point that the board was probably beyond economic repair and there was a high risk of the domino effect – one component failing can overstress others that survive the initial failure but which will fail before too much longer. I had probably already been experiencing that. NCE confirmed that diagnosis and they offered a replacement board for US$80 including taxes and postage to the UK, which is probably a very good deal for most modellers. However, I knew that I could build a MERG booster for a fraction of that cost. Unfortunately the standard MERG Booster was too large to fit inside the case so I couldn’t rebuild it as a 5 amp unit but I could comfortably fit the 3 amp mini-booster that I had already built for my planned power districts.
I wanted to retain the front-panel connections so I cut the damaged NCE circuit board near the front and attached the NBJ circuit board to it. The pictures below show a standard NBJ board alongside for comparison.
There are detail differences with LEDs being on or off board and I needed quite a few link wires but these were simple to install. I now have the benefit of an audible as well as a visible indication of a short and the cutout working. The retry period is longer and it can withstand an indefinite short. The front indicator lamp is now a two-colour LED which shows green for track power present and red for a fault.
Since it uses the same front-end as the MERG Booster, it shares the feature of bleeping for two to three seconds at power-up – a minor annoyance. The power input has been transferred from the front to the back and is now a regulated 15V DC instead of an unregulated 16V AC but all other connections are as original.
The replacement NBJ installed within the NCE PH-PRO case