Recently I have noticed high freq. screeching noise coming out from my laptop's adaptor. I opened it up and found that it came from somewhere around a diode named egp10a. I checked it (unplugged) with a multimeter disoldering only one end and saw that it works fine (no reverse voltage leak detected).
Later, I wanted to power the board without soldering the cathode to the board to see if the noise really caused by this diode. As I plugged the adapter the fuse blew and gave that burning smell. I found another identical fuse and replaced it and soldered the diode completely back again. Hovewer the new fuse also blew.
As someone who is very keen on learning electronics I would like to know what would be the problem and what I did wrong. I would appreciate if you guys guide me through learning the basics of electronics or share a source where I can learn this stuff.
I have noticed a new component with a burn mark on it located near the FETs (?). I do not know how it's named.
This adapter is becoming my learning kit now I guess since I consider buying a new adapter.
Do you guys think that the SMD caps under the board close to the diode legs I removed would be the cause of the noise I mentioned before?
Edit & Update 2:
- I have replaced components shown in the pictures with the equivalent once (I suppose(!))
- ***Used 11N60C3 instead of damaged STP11NM60AFP
- With the new parts put together I get no output voltage at all. (Fuse don't blow anymore)
- Do shorted caps might cause this?
- Please refer to the picture below where I get 308v output. Is it normal? (standard for my country is 220v)
Note: The power supply's model is ADP-65YB B and rated as 19V @ 3,42A. (Would it be okay if I used 19V @ 4,74A which I already have lying around?