Solved

surface mount device codes

Posted on 2015-01-07
8
110 Views
Last Modified: 2015-01-16
has any body got any idea what a surface mount device is with marking GFN 38 and also a diode symbol with its legs wrapped around to form a capital S. the device is 7mm long 5.5 mm wide and 2 mm deep, the two connections are on the short ends. it measures 4 ohms. It is in a dog perimeter minder circuit board , no bar marking on either end . just the symbol and text . the low value of ohms is causing over current draw on the 12 volt supply . i have extensive google search with  no success . removing the device from the board has solved the problem and it appears to work correctly . but mave not tried it with the dog collar.
Thanks for assistance in advance.
0
Comment
Question by:TopTed
  • 4
  • 3
8 Comments
 
LVL 27

Expert Comment

by:d-glitch
Comment Utility
Presumably the circuit was working, then it stopped working, and you noticed the suspect part was getting hot.  I think what you have is a failed protection diode.  The circuit will work fine without it, but it will be at increased risk of damage from line voltage surges.
0
 
LVL 47

Expert Comment

by:dbrunton
Comment Utility
I believe FN means Flat No-Lead.

However I can't get any further than that.
0
 
LVL 27

Accepted Solution

by:
d-glitch earned 500 total points
Comment Utility
A close-up photo of the circuit, suspect part, and logo could help a lot.  
There are dozens (if not hundreds) of possible manufacturers and many thousands of possible part numbers.

I believe the part is something like one of these:  http://www.vishay.com/diodes/protection-tvs-esd/do-214ab/
Bipolar protection devices would not require an indicator band.
The suspect device probably wouldn't have measured 4 ohms when it was new and working.
0
 

Author Comment

by:TopTed
Comment Utility
0
Highfive Gives IT Their Time Back

Highfive is so simple that setting up every meeting room takes just minutes and every employee will be able to start or join a call from any room with ease. Never be called into a meeting just to get it started again. This is how video conferencing should work!

 
LVL 27

Expert Comment

by:d-glitch
Comment Utility
Thanks.  That isn't the official logo for ST, but they would probably be irked if another company used that mark.
I'll resume the search there.
0
 

Author Comment

by:TopTed
Comment Utility
If there is no further comment , i think i will put it back into service and hope there are no surges. thanks for looking , I have had no further success either.
0
 
LVL 27

Expert Comment

by:d-glitch
Comment Utility
I have looked at the ST website and found more than a hundred of these parts with 3-letter codes, but none of them is a match for yours.  Some of the relevant data sheets are attached.  The 3-letter codes are on page 8.  The middle letter is always U or B (for unipolar and bipolar).  And the logo looks different too.
CD00001333.pdf
CD00001366.pdf
0
 

Author Closing Comment

by:TopTed
Comment Utility
I chose one of the vishay bidirectional devices as they were the same dimensins . i have put it in the pcb  and returned it to the customer and it is working ok. Thanks
0

Featured Post

Better Security Awareness With Threat Intelligence

See how one of the leading financial services organizations uses Recorded Future as part of a holistic threat intelligence program to promote security awareness and proactively and efficiently identify threats.

Join & Write a Comment

Suggested Solutions

Title # Comments Views Activity
Dual Output 15 84
Questions about a reed sensor circuit? 13 201
Lenovo Drivers won't take 3 52
iPhone 6S - ios10 - Text Messaging sounds 2 47
Introduction: When experiencing some peculiar problem with the functioning of your PC, how many times has it happened that you look for a solution and even google can’t help? It could be that you are one of the only few people on earth who ma…
Polish reports in Access so they look terrific. Take yourself to another level. Equations, Back Color, Alternate Back Color. Write easy VBA Code. Tighten space to use less pages. Launch report from a menu, considering criteria only when it is filled…
This video demonstrates how to create an example email signature rule for a department in a company using CodeTwo Exchange Rules. The signature will be inserted beneath users' latest emails in conversations and will be displayed in users' Sent Items…

743 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

16 Experts available now in Live!

Get 1:1 Help Now