bwck2000

ok，I think i will have my dy294 very soon

Thank you kevin gilmore. i have no idea they are fake or not Can a ordinary digital muitimeter do the job? Or do i need anything specialized for transitor testing

https://drive.google.com/file/d/0BwSbnuGaw37aVk9fdTU1SVhYRlE/view?usp=sharing Left to right: j79,K216,c3675,a1968 there are markings on each transistor but some of them are quite hard to see

Curiously，my a1968s in the psu board are working somehow,but a total replacement is seems to be the only solution. And anyone knows where is the best place to source the sands?Are they still avaliable?thanks a lot for all the advice.

Thank you for all the reply. RE Craig Sawyers Both channel failed and the parts are correctly wired and checked for several times. As yousaid maybe it is probably due to the sands. Maybe a all-around replace of sand is needed,which is the thing i want to avoid the most. I am in Hong Kong and in fact stores from mainland china have all the parts i need at a unbelievable low price, 20cent USD for 2sa1968 for example,but the reliability is as low as the price observed from my failure of the project.

First, sincere thanks to everyone who contributed in the forum.I cannot start the project without resources from here. Recently I have finished my KGBH build but it isn't working.The observable problems are the two LEDs connecting 2sa1968 and the one connecting 2sc3675 do not light up as well as those 1968s not heating.Curiously, the amp works for a second every time after i turn the power off,right after the extinguish of the leds connecting the + and - 15v supply. The PSU unit is measured of giving the right voltage. I once thought of giving up the project but before that I try my luck to see anyone who once encounter the same problem or know anything about it. Thank you.