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Electronics => Projects, Designs, and Technical Stuff => Topic started by: Romain on February 15, 2018, 09:49:19 pm

Title: Help to identify a SOT23-6 from its marking?
Post by: Romain on February 15, 2018, 09:49:19 pm
Hi

I'm trying to fix a LCD driver board. It's a LCD kit I bought and I do not have any datasheet nor schematic with it...
One of the power supplies capacitors is microphonic and the noise is just terrible  :palm:
At first I tried to swap the 1µF capacitor with a new 4.7µF capacitor but it made the matter worse. I'd like to get to the bottom of this, and have a look at the converter's datasheet.

The component is most likely a Buck converter converting the 12V in to 9V out, probably driving the LCD backlight.
The device marking is "W659".
Anyone who could help me with that?  :-+
Title: Re: Help to identify a SOT23-6 from its marking?
Post by: sstepane on February 15, 2018, 10:43:12 pm
Hi,

I do usually check the sites for smd markings:
http://www.s-manuals.com/smd (http://www.s-manuals.com/smd)
https://www.semicon-data.com (https://www.semicon-data.com)
http://kazus.ru/datasheets/smd/index.html (http://kazus.ru/datasheets/smd/index.html)
http://www.smdmark.com/en-US/smd-code-fd2.html (http://www.smdmark.com/en-US/smd-code-fd2.html)

There are some more sites if You google with smd markings.

However, another very good source for smd markings is taobao. I would search like "W659 SOT23-6" or what is chip packages size and if it sells there - there will be partnumber.

Hope it helps. It did many times for me.
Title: Re: Help to identify a SOT23-6 from its marking?
Post by: Romain on February 17, 2018, 07:16:06 pm
Thanks sstepane. I could not find anything on the websites, but I'll keep them for future reference  :-+
I found a drop-in component on Mouser : https://www.mouser.com/ds/2/115/AP3211-271560.pdf (https://www.mouser.com/ds/2/115/AP3211-271560.pdf)
I'm almost certain that it's not the exact same one, but probably close enough to start tinkering with ! :-/O