I am sorry to say that I too am not having luck verifying this time at this time.
Hi @oscar2 ,
“18” yields only some pre-biased transistors, which do not apply here. If the code is “1B” then it could be BC846C or MMBT2222, i.e. a general purpose NPN. You’d need to measure the package dimensions for the correct case.
Cheeers, heke
Reading it as “1B” rather than “18” may suggest a generic small-signal NPN device of 2222 or 846 flavor.
Investigation of the circuit to further inform the idea is advisable.