Hi All
Someone accidently connected a 240v AC supply to my SESTOS Counter C2S-R-220 unit's 12v DC out terminals. Apparently there was a flash and the house circuit protection device tripped (cut the power).
On opening the unit for inspection, I can clearly see damaged transistors, resistors, and some desoldered joints caused by the heat generated by the fault. All other components "appear" unaffected. I include a picture below (visible damage to surface mount components on bottom right hand side):
I cannot clearly see the markings for components Q5 (I can just make out 2T1), Q6, R19, and R20 (472 possibly).
I have a new unit on order already and wondered if it was worth having a go at replacing these relatively cheap SMB components to fix this unit. A little project I guess...
When the 240v supply is attached to the correct input terminals the unit starts up OK and I can access the menus etc. I suspect it is functionality like start, pause etc that is impacted by the fault because they need the 12v DC as supply. The unit makes a humming noise when I try to start counting as a result.
Anyone think it's worth trying to replace the damaged components? if so, how can I tell which resistor and transistor to select as replacements for the ones I can't identify? I can tell that the resistors are 0603 size and the transistor is SOT-23 following measuring.
It was me who blew it by the way a moment of complacency....
Someone accidently connected a 240v AC supply to my SESTOS Counter C2S-R-220 unit's 12v DC out terminals. Apparently there was a flash and the house circuit protection device tripped (cut the power).
On opening the unit for inspection, I can clearly see damaged transistors, resistors, and some desoldered joints caused by the heat generated by the fault. All other components "appear" unaffected. I include a picture below (visible damage to surface mount components on bottom right hand side):
I cannot clearly see the markings for components Q5 (I can just make out 2T1), Q6, R19, and R20 (472 possibly).
I have a new unit on order already and wondered if it was worth having a go at replacing these relatively cheap SMB components to fix this unit. A little project I guess...
When the 240v supply is attached to the correct input terminals the unit starts up OK and I can access the menus etc. I suspect it is functionality like start, pause etc that is impacted by the fault because they need the 12v DC as supply. The unit makes a humming noise when I try to start counting as a result.
Anyone think it's worth trying to replace the damaged components? if so, how can I tell which resistor and transistor to select as replacements for the ones I can't identify? I can tell that the resistors are 0603 size and the transistor is SOT-23 following measuring.
It was me who blew it by the way a moment of complacency....