dell E173Fpf burnt parts

[picturevalve]

Re: dell E173Fpf burnt parts

Hi, my board has none of the damage suffered by the op. Just C868 and R852. It looks like R852 will be 0.21 ohm as the dell 2209wa monitor has just such a resistor in the ht as a fusible 1W resistor. In my board R856 is a 5.1 ohm not 15 ohm. Second jpg shows side of heatsink where C868 committed capricide.

[picturevalve]

Re: dell E173Fpf burnt parts

Second image. I just wonder whether the "hot" side of the ceramic was touching the heatsink.

[budm]

Re: dell E173Fpf burnt parts

Can I see the bottom side pf the board where C868 cap is to see how it is connected?
Ceramic cap tends to fail as shorts circuit.

[picturevalve]

Re: dell E173Fpf burnt parts

C867 R852 and C868 form a pi filter on the ht supply so C868 is connected from R852 to ground. As C867 is 10nF 1kV, I suspect C868 is of the order of 22nF 1kV.

[picturevalve]

Re: dell E173Fpf burnt parts

The 2209WA monitor has a similar arrangement with a bead in the pi not the resistor.

[picturevalve]

Re: dell E173Fpf burnt parts

Replaced C867 and C868 with nice blue 10nF 1kV ceramics, the surviving C867 didn't look the part. Replaced R852 with a 0.22 ohm 1W fusible. All o/k.

[Davi.p]

Re: dell E173Fpf burnt parts

Hi, i have fixed one with same O.P. problem, lastly after 5 or more tries, 5 expensive mosfets dead and more, if you are interested on how email me..