Hello,
I have a non-working IR lamp Medisana IR 850.
Initially, when I plug the item into mains I had to press the button once to start it. The function is pretty simple - every button press add 5 min to timer (probably the unknown IC I am looking for) up to 15mins. The main problem was that the relay was not closing for some reason and the lamp did not glow.
I found the problem which was a blown zener dionde, but unfortunately while measuring on live my probe slipped and shorted the black capacitor next to the zener diode with mains and it blew up...
I've replaced the capacitor and the zener and from this time the circuit is no longer working. What is happening is once I plug the item into mains every possible LED light up and the board is not responding to the button. I've checked every possible component that could be checked and what's left is the unknown U2. Do you think it's possible to find what's the IC? From what I see the pinout is the following:
1, 2, 3 - controlling timer indicator (1 active led = 5min, 2 active led = 10mins, 3 active led - 15 mins)
4 - VCC
5, 6 - NC
7 - connected to the button and also to positive through resistor
8, 9, 10 - NC
11 - GND
12 - this is controlling the relay. If I pass more than 7.5V to this pin the relay is closing
13 - responsible for running a fan which connector is located on the right side of the board
14 - main LED indicating the item is running, not sure if it has other responsibilities...
I found some marking on the bottom of the chip, but probably useless.. Check the attachments for more information.
Any suggestions are welcome.
Thanks.
I have a non-working IR lamp Medisana IR 850.
Initially, when I plug the item into mains I had to press the button once to start it. The function is pretty simple - every button press add 5 min to timer (probably the unknown IC I am looking for) up to 15mins. The main problem was that the relay was not closing for some reason and the lamp did not glow.
I found the problem which was a blown zener dionde, but unfortunately while measuring on live my probe slipped and shorted the black capacitor next to the zener diode with mains and it blew up...
I've replaced the capacitor and the zener and from this time the circuit is no longer working. What is happening is once I plug the item into mains every possible LED light up and the board is not responding to the button. I've checked every possible component that could be checked and what's left is the unknown U2. Do you think it's possible to find what's the IC? From what I see the pinout is the following:
1, 2, 3 - controlling timer indicator (1 active led = 5min, 2 active led = 10mins, 3 active led - 15 mins)
4 - VCC
5, 6 - NC
7 - connected to the button and also to positive through resistor
8, 9, 10 - NC
11 - GND
12 - this is controlling the relay. If I pass more than 7.5V to this pin the relay is closing
13 - responsible for running a fan which connector is located on the right side of the board
14 - main LED indicating the item is running, not sure if it has other responsibilities...
I found some marking on the bottom of the chip, but probably useless.. Check the attachments for more information.
Any suggestions are welcome.
Thanks.
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