700B blew one Right channel 5A supply fuse

[NavLinear]

Lee - I went back and reread the beginning of this thread and those extra components shown in Gary's photos that are stood up (flying) concern me. It looks like some added hardware to mask (or maybe fix) a previous issue. Did you guys figure out what was up with the added components?

 

[laatsch55]

O've seen that quite a bit actually Dennis, an on the fly factory fix for something..

 

[62vauxhall]

minus POINT five six seven??

Yes.

 

[laatsch55]

Ok, now the voltage at the collectors of Q1,Q2 left and right....

 

[NavLinear]

O've seen that quite a bit actually Dennis, an on the fly factory fix for something..

Ok - don't want to overlook anything.

 

[laatsch55]

Thank you, I can do that ya know...

 

[62vauxhall]

Ok, now the voltage at the collectors of Q1,Q2 left and right....

Left Q1: 8.9V DC at C
Right Q1: 24.75 volts DC at C

Not minus voltages.

 

[laatsch55]

The bottom has to be right Q1, correct?

 

[NavLinear]

Left Q1: 8.9V DC at C
Left Q1: 24.75 volts DC at C

Not minus voltages.

Don't forget Q2 - it's the other half of the differential pair.

 

[62vauxhall]

The bottom has to be right Q1, correct?

Yes, I just edited the post.

 

[laatsch55]

5 posts above ya there Nav,

Q2 collector now Gary, heft and right...

 

[62vauxhall]

Don't forget Q2 - it's the other half of the differential pair.

Left Q2: -.552 volts DC at E (minus)
Left Q2: 8.83 volts DC at C

Right Q2: -.564 volts DC at E (minus)
Right Q2 24.41 volts DC at C

 

[laatsch55]

Now the base of Q1,Q2 left and right...

 

[62vauxhall]

Now the base of Q1,Q2 left and right...

Left Q1: 1.1MV DC at B (minus)
Left Q2: -1.5MV DC at B (minus)

Right Q1: -.4MV DC at B (mnus)
Right Q2: -19.2MV DC at B (minus)

 

[laatsch55]

Emitters of Q3,Q4 right and left...

 

[62vauxhall]

Emitters of Q3,Q4 right and left...

Left Q3 Emitter: 9.68 volts DC
Left Q4 Emitter: 9.59 volts DC

Right Q3 emitter: 25.48 volts DC
Right Q4 emitter: 25.27 volts DC

 

[laatsch55]

Ok, now the base of Q3,Q4 left and right.....everythjing still cool?

 

[62vauxhall]

Ok, now the base of Q3,Q4 left and right.....everythjing still cool?

Left Q3 Base: 8.93 volts DC
Left Q4 base: 8.92 volts DC

Right Q3 base: 25.26 volts DC
Right Q4 base: 24.37 volts DC

No outrageous heat but both Q10's have warmed up some especially Left channel.

I'm going to need some sleep soon. Must be up in 4.5 hours.

 

[laatsch55]

OK, shut er down Gary, I need some sleep too...

 

[62vauxhall]

OK, shut er down Gary, I need some sleep too...

Post again at your convenience. I'll monitor the site.