Replace component on circuit board -Burned out transistor?

Thread Starter

Sam Said

Joined Jul 29, 2019
9
Hi all, I've recently been given this circuit board (from a Meta car alarm) with what I think is a burnt out transistor, problem is I'm not sure what the component is & what I can use as a replacement (please see the photo). Any ideas anybody.

Many thanks in advance
 

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dl324

Joined Mar 30, 2015
17,142
Unfortunately the schematic is not available
Check the board and make a tally of all of the part numbers for the 3 pin devices in the same package as the bad one.

Trace the components around the bad device and make a schematic. Of course, you'll only be able to show a three terminal device for the bad one.
 
Check the board and make a tally of all of the part numbers for the 3 pin devices in the same package as the bad one.

Trace the components around the bad device and make a schematic. Of course, you'll only be able to show a three terminal device for the bad one.
That's what I would do. I think that's the most feasible way to obtain useful information.
 

Thread Starter

Sam Said

Joined Jul 29, 2019
9
Many thanks for the help thought I'm not sure how I'd work out what the component is by making a schematic. As I'm not in a hurry I think the best solution is to wait for another unit to turn up (which they do from time to time) so I can find the part number. I'm still open to suggestions in the mean time.
 

dl324

Joined Mar 30, 2015
17,142
I'm not sure how I'd work out what the component is by making a schematic.
We'd attempt work out what the unknown three terminal part was by analyzing the schematic you drew. You'd have to look up part numbers for any components around the bad device to create the schematic.
 

dl324

Joined Mar 30, 2015
17,142
Found what I believe to be the same component hidden in the corner of the board, now to try and work out what it is....
Can you post the markings?

It looks like Y11W with a 42 rotated 90 degrees.

There are a number of resources on the WEB that give SMD code cross references.

From SMD Codebook:
upload_2019-7-30_9-24-52.png
 

dl324

Joined Mar 30, 2015
17,142
What do you think chaps shall I go for it, click here
I wouldn't go for it. Y11W and Y11 aren't likely the same device. There is no standard convention for SMD markings and multiple vendors could use the same marking for different devices.

Without a schematic for the circuit, a more reasonable option would be to characterize a good part with the same markings.
 

Thread Starter

Sam Said

Joined Jul 29, 2019
9
Maybe your right, I'll wait for another circuit board to come my way.

Many thanks for all the help & suggestions
 
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