ID Component

[OpenCircuit]

Trying to ID these chips so I can proceed with testing- they read:

                                   L1213
                                   817 B
                                      W

The L is leaning to the right towards the 1 (top line)

Did search Google with numerous strings. One result was a photocoupler and the other a voltage regulator. Sorry I can't discern....I'm  learning 


Thanks for any help.

Here is a photo of the four-legged monsters:

[helius]

Lite-On LTV-817 optoisolator

[JoeN]

You can tell it is an optocoupler just by that packaging.  I don't know anything else that gets put into that package.  Is this a power supply?  Optocouplers are very common to connect signals from the high voltage to low voltage side.

[OpenCircuit]

Thank you both a lot !

Joe, yes a power supply for PC (https://www.eevblog.com/forum/repair/atx-power-supply-dead/msg1166236/#msg1166236).

[DTJ]

Maybe one of these:


https://img.ozdisan.com/ETicaret_Dosya/28512_2166956.pdf

[OpenCircuit]

Whichever, can terminals 1 and 2 (anode cathode) be tested with a simple diode test on DMM?

[DTJ]

Whichever, can terminals 1 and 2 (anode cathode) be tested with a simple diode test on DMM?

Yes, see data sheet page 2.

Vf = 1.25V typ up  to 1.6V max.


I'm assuming your power supply has failed?
Perhaps look at the electrolytic caps, input rectifier and switching semis.

[OpenCircuit]

Whichever, can terminals 1 and 2 (anode cathode) be tested with a simple diode test on DMM?

I'm assuming your power supply has failed?

DTJ, here is a link: https://www.eevblog.com/forum/repair/atx-power-supply-dead/msg1166236/#msg1166236