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#4125
Billy
Moderator

All of your components look to be of the correct value the only one I can’t see clearly is R4 (22K) the colour bands should be

red, red, black, red, brown

 

Looking at the schematic and comparing your transistor voltages to what they should be I suspect you may possibly have a solder bridge or poor solder connection giving you your strange readings

 

Q1 Collector and Q2 Base should have the same voltage being directly connected to each other after R3 (51K) looking at your readings I think they do 1.75v

 

I think your voltages have Q1 and Q2’s Emitter and Collector the wrong way around and what you have as the Emitter is actually the Collector and visa versa your empty socket readings would make more sense that way

 

Q1 Emitter is only connected to ground and the fact you have 5.82v? there again makes me suspect a solder bridge / poor connection somewhere, continuity check Q1s Emitter to ground

 

Check Q1 Collector has continuity with Q2 Base

 

Check each transistor empty socket making sure that each of the 3 socket holes do not have continuity and double check the solder joints on the sockets

 

Check that R3 left side nearest the IN pad has continuity with Q1 Collector ( in red dots below on the pcb image)

 

This will give us an idea of where there could be a bridge or bad connection

 

 

Just for info 2N3904 pinout