That "L9948" number is most likely an internal manufacturers part number.
Trace out the circuit around the unknown IC.
Post it here if you like.
My bet is on it being a 555 timer IC.
one lead gets 15vac straight from the circuit breaker. One lead goes to a resister, another to a diode, the fourth goes to a second IC with the same markings on it. One of its leads goes to a cap, another goes to a electrolytic cap and the fourth I forget where it goes.
ok, that did not work. I absolutely LOVE when I follow directions exactly, and it dont work. What is that button for that says "insert image", but then requires a url??? I uploaded to photobucket and inserted the urls using that button.
last night i tried to log on 4 times, it said each time pswd was wrong. Well, now it just accepted it. Oh well.
So, do you think that this IC is a weak link that could have been destroyed during a lightning hit? 3 different circuits in my house were damaged, including the ac/heat control st9103a. I tested the 3 relays on this board and several of the resisters and diodes. One of the leads on one of those ICs is directly connected to the 115vac in, so its live 24/7. Can I replace it?
what are you up to?
Do you have any idea what you are trying to do?
Do you have any experience in handling mains operated or live circuits?
Tell us what you know about live circuits and what you have to trouble shoot. I will not be engaged in anyone who have no experience in handling live circuits.
This is for safety reasons, for your safety
Your not my mother. You are not responsible for my safety. That being said, since I've already removed, tested and replaced several components on this board...I do know what I am doing. Im only here because I cant identify that IC and neither can several electronic supply houses.
I do not believe in the throw away society and would rather fix then replace this board. The other day my neighbor threw away a NEC flat screen monitor. A little research on the net and a few 470ufd caps and its good as new.
My house was built in 1954. i've added several circuits to it (new fuses, new wire, climbing in the attic, pushing wires down the walls. I've added a ground wire to some of the existing two wire outlets. I had the central AC/Heat unit installed(2001). I know when something is beyond my abilities, then and only then I pay the pros.
If need be I will replace the board, but if I can fix it, I save money and the land fill.
Safety issues are of primary concern, but since u know what you are doing then let's get cranking...
What I do if I couldn't get a schema is study the circuit.
I can help if you show me or give me an idea of what you have.
If you want to repair the board then you have to do some trouble shooting.
If you not sure where to look at then show me the pics of your board, closeups.
This way I can guide you
By looking at the board I can tell which is which