Voltage Mode PWM Controller -burned or ok?

[lazyluke]

Hi, I am asking for opinion of an experienced person on this issue. This thing has a small dark smudge across it- not sure if its possible its burned or it might of originally be like that- picture below

 

[tpetar]

Circuit/device working or not ?

Do you have photo from other side ?

Yes its strange dark line on case.

Sometimes in factory worker for device inspection marks with felt pen over IC case when checked. But this...

 

[lazyluke]

Circuit/device working or not ?

Do you have photo from other side ?

Yes its strange dark line on case.

Sometimes in factory worker for device inspection marks with felt pen over IC case when checked. But this...

The device is not working, one transistor blew and I need to change a lot of components related to that part of the board...

The other side looks ok, no signs of overheating, however this thing looks fragile and its surface mounted so even if it did fail, I assume it wouldn't necessary show on other side. (I can make a picture tomorrow at work)

I will try to use ethanol to remove it in case its some sort of weird ink...

If it was a normal component I would not think twice about replacing it, however I am not experienced with changing this type of device (I assume its very heat sensitive)

 

[tpetar]

No need for pic of other side, we trust you. :smile:

Maybe they try just to remove code mark.

 

[lazyluke]

Alcohol didn't work, but sand paper did lol... I guess the marker from QC just etched into the surface. Thanks for advice

 

[tpetar]

You must use Isopropyl Alchole for that.

 

[lazyluke]

You must use Isopropyl Alchole for that.

Actually that was the one I used... We ran out of ethanol so I took isopropanol.. Still didn't work