Thetford n150 fridge/freezer: No power :(

[SacStar]

My Thetford N150 fridge, orinigal issue was fridge failing to stay lit on gas. There was a fault with the heat detection circuit on the power control board, meaning the PCB needed to be replaced.

So..

I successfully replaced the PCB. Whilst the PCB plastic casing was open, but all connected up, I tested it multiple times, all working great with power and the original gas fault resolved.

Then to finish up the job, I put the PCB plastic casing back together. Bit of a tight squeeze getting wires inside the casing. When I went to do one final test after all that was wrapped up, the fridge had no power at all. Leaving me in a worse position that when I started.

The 30amp, 12v fuse had blown on my main Motorhome 12v distribution unit. I replaced that, but no resolution.

Using multimeter, i confirmed 12v is still getting the PCB board by reading the 12v terminal on the PCB. All fuses on the board working fine too.

I thought that maybe the control panel board on the front of the fridge had gone during the trip. I also wondered if I’d damaged the cable between the PCB and the front control panel, when assembling the PCB casing.

I disconnected the cable, which runs from PCB to the front control panel board, and done a DC reading by sticking the multimeter pins into the cable connector (whilst the other end was still connected to the PCB). I barely got any reading, max 0.02v. I think I should be expecting to see 12v reading from the cable, is that right?

Is it plausible that I’ve damaged the cable between PCB and front control panel, when putting the PCB casing back together, and shorted out the fridge fuse? Any other thoughts?

I know this is a rabble, but I’m at a loss. 2.5k for a new 3way fridge. Grudging the thought of that. Any help would be greatly appreciated.

 

[shrek snr]

DIY destroy it yourself.

 

[scotjimland]

Is it plausible that I’ve damaged the cable between PCB and front control panel, when putting the PCB casing back together, and shorted out the fridge fuse? Any other thoughts?

that certainly sounds possible,

you may have loosened/damaged a soldered connection or have a 'dry join't on the PCB which would explain the 0.02v

good luck tracing the fault.. and welcome to the forum

 

[GeoffnDee]

It is possible that your fridge PCB has two 12v supplies , a high current (30amp) for 12v heater operation and also a low current 12v supply for fridge control operation , if so , have you checked that the fridge control low current supply fuse is ok.

 

[SacStar]

It is possible that your fridge PCB has two 12v supplies , a high current (30amp) for 12v heater operation and also a low current 12v supply for fridge control operation , if so , have you checked that the fridge control low current supply fuse is ok.

Yeh, all fuses are good. On the PCB board there is a 240v fuse, a 20 fuse and a 2 fuse, all allow a closed circuit when tested on multimeter

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[GeoffnDee]

Have you checked both 12v supplies are getting to the PCB .