Technics SA-424 FM/AM preset tuning circuit LCD lost

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Built with secure and safe form electric shock.

Member here showed this pic.
 

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How to install a To 220 transitor, same as this video, you need a mica insulator film and a screw insulator the white plastic ring.
After install the transistor, please measure the transistor pin C(middle pin) does not short to ground.

YouTube




This is how my heat sink is looks like... But i removed it and i have the same reaction. I don't think that this is the problem... :sorry:



I have to tell you that the only fuse that i have right now for replacement is 2A/250V but fast blow. Not slow blow that was the original...
 

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When the circuit has all the parts on R719 is too hot!!!!

if no load connected, R719 should not hot, it just supply low current to 6v zener diode D712, please check this part again.

This is how my heat sink is looks like... But i removed it and i have the same reaction. I don't think that this is the problem... :sorry:

Ok, I will think again for Q703
 
So... it was a big mistake of me and i feel sad... two cables that was supporting the analog display of frequency was naked and shorted...:mad:
I had also changed a c705 100μ/25V.


i fired up and... i ve heard a crack... from then i the relay doesn't click....



All the measurement of voltages was the same as the previous...


I afraid that i lost an amplifier and do a research around protection circuit.... :headbash:
 
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