Another Power supply fail

Discussion in 'Power Electronics' started by IMP002017, Jun 16, 2017.

  1. IMP002017

    Thread Starter Member

    Jan 28, 2017
    187
    30
    So this one isn't mine. However it seems that one of my friends has a SMPS that has a LCD screen on the top side of the board and XL4016E1 chip underside. Mine with the 4015 also had the LCD and was able to replace the chip without total fail of my LCD however I did get everything installed in mine and back up and running without fail. Another thing that I don't want to have to worry about is the 2 50v SM 220 caps. There is one that is right up close to the Chip so I will for sure remove that with Chip Quik before I remove the chip. I am just wondering if there is something that I can get to help insulate the board outside the chip area so I can remove the chip without having to de-solder the LCD? Again this unit is like mine however I don't own it and don't want to have to buy a new one to replace because it took just that much longer to get the chip off and damaged the LCD on the other side? To be honest when I removed mine at first glance I thought I had cracked my LCD. however it is working great. I know captains tape isn't going to be enough protection for this I really don't have the room to remove with out hot air on my normal chip removal because it is compact design and want to only replace what is damaged.

    If only option is Removing the LCD to be safe that is what I will do. I just thought there maybe others out there that have worked repairs on dbl sided boards with LCD on other side that may have a tip of something to take the extra heat?

    James
     
    Last edited: Jun 16, 2017
  2. IMP002017

    Thread Starter Member

    Jan 28, 2017
    187
    30
    Well I didn't want to take the chance so I removed the LCD and then took off the 470uF 50v Cap (Thought it was like mine with 220uF) and the chip came off very easy. Not sure I like the way it was installed to start with. I confirmed that my friend wanted it back the same way? I personally don't like the idea however that is the way it was. the Output tab is cut at the 1/2 mark and mounted like a TO263 XL4015 is mounted. Installed it and tested it over some nice loads and made sure that everything was working as it should. To be honest I think it just is a bad setup and not getting enough cooling. Testing loads at 1amp 2.25amps and and less with no issues. Once I started testing at 4.5amps and above it started to heat rather fast and the design don't seem to cool enough. Added a small heat sink.

    Sent him home with some longer stand offs and gave my .02 about adding a fan to the unit if he will use it at more then 4amps for extended amount of time. I think if he keeps it cooler it will last longer. The plus side the thing was built with a Fan port already installed.

    James
     
Loading...