I am trying to Identify this SMD component, Pin 1 GND , 2-VCC, 3-? Out I can identify top letter is C , Bottom is G11, I think it might be a transistor but it odd being connected to the main power rail. Part is from bremshey bike monitor. Unfortunately other identification is blocked out because it's burned out.
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3\$\begingroup\$ It's labeled 'U4', so it's an IC not a transistor. My guess would be a linear voltage regulator of some sort. You can see that transistors are labeled with a Q, as there's a big Q5 over to the left. \$\endgroup\$– brhansMar 30, 2018 at 0:58
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\$\begingroup\$ good point, to the left is a 3.3V LDO what type of IC would have the label Cxx G11? \$\endgroup\$– Ben NewsonMar 30, 2018 at 1:10
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\$\begingroup\$ ON the PCB it says CHANG YOW SM6665-K01 I tried to find the schematic but it's hard to find, \$\endgroup\$– Ben NewsonMar 30, 2018 at 1:12
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\$\begingroup\$ It looks like old Rotamola silkscreen before Laser marking was used. Looks like centre pin is 0V \$\endgroup\$– Tony Stewart EE75Mar 30, 2018 at 1:14
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\$\begingroup\$ So why the marking of G11? if it's not a transistor? \$\endgroup\$– Ben NewsonMar 30, 2018 at 1:15
2 Answers
I figured it out, It turned out to be an LDO 5.0V the way I solved it was I replaced it with a 3.3. LDO and it worked but the display was very dim. I figured the next one up would be a 5V regulator, so I desoldered one from another PCB put it on and it works like a charm. Thanks for your comments.
I agree. no idea,
but if one of the junctions isn't shorted determine if it PNP or NPN with a DMM then choose a 1W transistor that makes sense for V*I
You can always use a bigger part not SMD with higher Vceo.
e.g. linked to switch Motor in regenerator mode 80V? then 100mA, low V switch? then 30V 500mA
e.g. NPN 2SD1463 , PNP 2SB1045 (100V 50mA)
At least it is not an LDO like U7.
What event triggered the failure?
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\$\begingroup\$ yes I saw this but I don't think DTB113ZKA is a SOT89 package, According to the PCB Pin 1 is GND and Pin 2 is VCC, Pin 3= Vout I guess, If it's a Digital Transistor why would it be connected to the main VCC? \$\endgroup\$ Mar 29, 2018 at 23:49
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\$\begingroup\$ not normally marked... probably part of other markings burnt out \$\endgroup\$ Mar 30, 2018 at 0:39
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\$\begingroup\$ Unfortunately, I can't determine if it's PNP or NPN because each pin is an open. Any ideas to determine the original C B E pins? \$\endgroup\$ Mar 30, 2018 at 0:59
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\$\begingroup\$ Is there a way to test this without replacing the part? Eg if pin 1 was GND and 2 was VCC then could I just put a jumper from pin 2 to 3, if it's acting like a switch? \$\endgroup\$ Mar 30, 2018 at 1:05