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Old 11-20-2018, 10:56 AM
Shibby Shibby is offline
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Join Date: Mar 2017
Posts: 31
So this is where I get stuck. I tend to be decently good at troubleshooting things as this is what I do every day at work but I am missing the fundamental understanding of how circuits work. Knowing that I am hoping that you guys might be able to steer me in the right direction.

I went ahead and pulled the board last night so I could get a good look at it. After a visual inspection of all of the components nothing seemed too fishy. The smoking resistor I mentioned was indeed burned but seems to have retained its resistance when tested out of series. When in series I get clear continuity between both legs of the resistor. Of course this means that there is continuity between the pads that each leg of the resistor is on.

This is where I get lost. If you look at the solder side photo that I attached in my last post and locate Transformer 5004 (T5004) you will see the 2 pads that I am referencing. Unfortunately this service manual does not reference the "burnt" resistor that also shares these pads but if you look at the picture again right where it says T5004 imagine the resistor being right there. On my board it is labeled as R5095.

So on my board these 2 pads are shared by 3 components. R5095, C5015, and T5004. After pulling both R5095 and C5015 There was still continuity between the pads. This obviously left me with just the transformer. It is hard to see in the solder side diagram/image but on the laft side of the transformer there are 4 legs. 2 on the upper pad and 2 on the lower pad. You can see the holes for these legs as faint white dots on each pad. On the right side of the transformer are 2 legs thought there are 3 individual pads. Only 2 of the pads are used. According to the parts list this is a "Choke Transformer". After doing a bit of research the configuration seems to match that of a common-mode choke configuration with the left side 4 pins being 2 separate inputs and the right side 2 pins being the output.

So I guess here is my question. Should all 4 of the pins on the left side of the transformer have continuity between them? If not I would thing that this is my issue as it is essentially bridging the 2 pads together. If they are supposed to have continuity then what should I be looking at next?

I really have no idea if I am even close to barking up the right tree here so please be patient with me. If it helps this is the NEC part number for the transformer with the description. 60906204 COIL,WIDTH CHOKE. That description may be a typo as nothing came up when I googled width choke.

Anyways.....Any ides here? I truly am lost.

Here is a picture to reference the resistor missing in the service manual
Attached Images
File Type: jpg Screenshot_20181120-115701.jpg (114.0 KB, 13 views)

Last edited by Shibby; 11-20-2018 at 11:01 AM. Reason: Reference picture added
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