Monday, 31 October 2011

Philips 190B Fuse blown arcing buzzing faulty.

This monitor had blown the fuse in the mains lead following a sparking sound !

I stripped it down, fairly straightforward. Undo all the screws at the back, the stand screws then two longer self tappers that hold the speaker bezel and screen bezel on. Then its a case of unclipping / prizing the bezels off.

The LCD panel then unclips from the case allowing it to be tilted out. The screws holding the psu / video board cover can be removed.

I powered the board on with the covers off and was greeted with the following !

So it was fairly easy where to look next. !

A poor connection at the PCB on the live wire of the mains input was the cause. The solder hole has a heavy duty insert to prevent this kind of thing but the heat and stress must have just got worse, leading to the arcing when the track finally broke. I suspect the internal inrush limiters meant that I could repeatedly produce the arcing in the video without the fuse blowing again.

It was cleaned up and re soldered with a bridge on the track to beef everything up.

Re assembled and monitor then working fine !

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