Help Identifying Components.

[Pete1972]

Hi, I need some help identifying some components, the component markings are UM8A, SM8A & UM11.

All of the components are physically the same, I initially thought they may be TVS Diodes but cannot find any information about them anywhere, they also differ from images of TVS diodes as they do not have the heatsink underneath which comes up the sides, they are mounted on a Logic Washer/Dryer control board, the actual manufacturer of the machine is Vestal and the board manufacturer is EGO Appliance Controls.

The Logo on the components looks like the General Semiconductor Logo.

I've convinced myself it is a diode of some kind, I have attached photo's of the UM8a, The SM8A and also a photo of where one of them is connected into a Viper 12A.

I haven't tested them yet as I will have to wait until the weekend to get them off the board, they may be perfectly fine but i'm just curious as to what they are.

Any help appreciated and thank you in advance.

 

[Tony Stewart]

The 1st is UM is the SMD (device) CODE and 8A is the year and month code
It is a high voltage low leakage power diode.


But there is no evidence that this is a faulty part..

 

[Tony Stewart]

THe offline regulator IC, however does show some heat stress around the board.

https://www.st.com/resource/en/datasheet/viper12a-e.pdf

 

[Pete1972]

Thank you Tony, I have spent the whole day trying to identify that, your help is most appreciated.

I did think the regulator IC looked like it had overheated a bit, I will order a replacement, better safe than sorry.

 

[Tony Stewart]

Check out the e-cap as well and other parts