trying to repair my car radio, need some help identifying a surface mount component

Thread Starter

sedemdeh

Joined Nov 18, 2004
11
my camera is busted but I not sure if I could have gotten a clear pic anyway..
the component in question has the markings as displayed in the pic..
I'm not sure if its a transistor or something else and I've tried to search but I don't have much to go on..

any help would be great, I just need to find something comparable
 

bloguetronica

Joined Apr 27, 2007
1,359
my camera is busted but I not sure if I could have gotten a clear pic anyway..
the component in question has the markings as displayed in the pic..
I'm not sure if its a transistor or something else and I've tried to search but I don't have much to go on..

any help would be great, I just need to find something comparable
It is an SMD component, but I can't really guess what it is. Besides the markings, can you see any sequence of characters?
 

beenthere

Joined Apr 20, 2004
15,808
The package could be for an SMT transistor, but there is no way to tell what polarity or kind from the illo.
 

Thread Starter

sedemdeh

Joined Nov 18, 2004
11
the circuit controls the lcd display on the radio. the leg on the side that looks like a Q is positive, and I can get the display to work by jumping that positive leg to the center leg..
My problem is that when that is done the radio draw more current even when turned off and could possibly drain the battery..
 

lightingman

Joined Apr 19, 2007
374
This device, as far as I can tell is an MMBT5088 If the marking is 1Q. NPN, vce = 30v.Hope this helps.....Daniel.
 

SgtWookie

Joined Jul 17, 2007
22,201
good call on lightingman's part.

If you can't find an MMBT5088, you might be able to use a 2N5088; that's the same transistor in a TO-92 case. I had to do that when I was visiting my folks in July for a week; couldn't find a SMT version of a 2n3904 to fix their cordless phone locally, and didn't have time to wait for one to be delivered. Took some careful lead bending and trimming to make it work, but work it did.
 

bloguetronica

Joined Apr 27, 2007
1,359
This device, as far as I can tell is an MMBT5088 If the marking is 1Q. NPN, vce = 30v.Hope this helps.....Daniel.
You are the man!:D

Now serioulsly, you can you tell exacly the type of the trnsistor by readind the marking "1Q"? Is there a table for these markings?
 

SgtWookie

Joined Jul 17, 2007
22,201
There are quite a few tables out there. In the past, standardization of markings was a huge problem, but it's getting better.

Here is a very useful site:
http://www.educypedia.be/electronics/datacomponent.htm

You'll still have "rummaging around" to do, but at least you'll have lots of stuff to look at ;)

One of the really nice things about that site is that it'll give non-ROHS compliant equivalents (that is, parts that may contain lead and other elements heinous to the environment) if available - very handy for those with well-seasoned "treasure boxes"

For example, a quick check shows that MPSA18 is a non-ROHS compliant but otherwise equivalent replacement for the OP's part.
 

Thread Starter

sedemdeh

Joined Nov 18, 2004
11
thanks for all the assistance guys, hopefully I can get this radio working properly again
 

bloguetronica

Joined Apr 27, 2007
1,359
There are quite a few tables out there. In the past, standardization of markings was a huge problem, but it's getting better.

Here is a very useful site:
http://www.educypedia.be/electronics/datacomponent.htm

You'll still have "rummaging around" to do, but at least you'll have lots of stuff to look at ;)

One of the really nice things about that site is that it'll give non-ROHS compliant equivalents (that is, parts that may contain lead and other elements heinous to the environment) if available - very handy for those with well-seasoned "treasure boxes"

For example, a quick check shows that MPSA18 is a non-ROHS compliant but otherwise equivalent replacement for the OP's part.
Very good resource! You should put this in the "Electronic Resources" section, if you didn't.

O.K. Fellas (and maybe girlies)..I cheated !!!!.... This is a good site for SMT identification...www.tkb-4u.com/code/smdcode/indexsmdcode.phpSo I don't know every SMT marking of the top of me head..Daniel.
I can't open the link! I think it is malformed. I think this is the link:
www.tkb-4u.com/code/smdcode/indexsmdcode.php

Everyone cheats, but of course, some cheat more (like Bill MS).
 
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