I recently received a free Sony SRT-V3 with some sentimental value. The unit did not power up. Opening it up I noticed the primary 4a fuse was blown. The fuse appeared to be a fast blow fuse. I replaced it with a slow blow and now the unit will power up. Now when turned on, the two emitter resistors (R725 and R726) glow bright. R725 is cracked and starts to smoke. The other two emitter resistors (R774 and R775) both test .01 on 20kOhms.
I'm trying to test components and remember classes from 25 years ago so please forgive my limit understands.
I tested the output transistors on my diode setting and Q713 is shorted, Q714 tests 066 both ways, Q764 tests 459 (black on base) 687 (red on base), Q763 tests 504 (red on base) 637 (black on base).
I'm wondering if I can get feed back on how I see things?
Seems obvious that the R725 and R726 need to be replaced. I believe R774 and R775 need to be replaced as well. Q713 needs to be replaced. I believe the other three output transistors need to be replaced. From what I understand PNP and NPN should not give readings both ways and voltage should read between .45V to .9V.
Am I correct in how I'm understanding my testing?
Lastly, where is a good site to go to to find replacement compontents? I've discovered el-component for replacement part numbers for the output transistors but I can't find anything to help find replacement MPC resistors.
Thanks in advance for any advice, feedback, and gentle insults.
I'm trying to test components and remember classes from 25 years ago so please forgive my limit understands.
I tested the output transistors on my diode setting and Q713 is shorted, Q714 tests 066 both ways, Q764 tests 459 (black on base) 687 (red on base), Q763 tests 504 (red on base) 637 (black on base).
I'm wondering if I can get feed back on how I see things?
Seems obvious that the R725 and R726 need to be replaced. I believe R774 and R775 need to be replaced as well. Q713 needs to be replaced. I believe the other three output transistors need to be replaced. From what I understand PNP and NPN should not give readings both ways and voltage should read between .45V to .9V.
Am I correct in how I'm understanding my testing?
Lastly, where is a good site to go to to find replacement compontents? I've discovered el-component for replacement part numbers for the output transistors but I can't find anything to help find replacement MPC resistors.
Thanks in advance for any advice, feedback, and gentle insults.
BE should be low impedance one way and high the other.
Same for BC.
EC should be high impedance both ways.
Amps can be pig to fix as quite often outputs going take drivers with them too so check all driver transistors and components around them.
Once fixed power up with a 30w mains lamp in series with mains to limit the current, just in case there are more problems.
Same for BC.
EC should be high impedance both ways.
Amps can be pig to fix as quite often outputs going take drivers with them too so check all driver transistors and components around them.
Once fixed power up with a 30w mains lamp in series with mains to limit the current, just in case there are more problems.