The Smoked 400

[mlucitt]

I feel your pain, really I do.

 

[laatsch55]

LOL!@!!!

 

[Gepetto]

Yes please, measure with D9/10 lifted. You don't want to worry about that piece of the circuit until you get the main loop working, which it is not presently.

 

[laatsch55]

31 volts on the rails, Q10 gets instantly hot, I mean finger burnin hot, 12.37 volts on Q4 base, 19.38 on Q5 collector, didn't get a 6L,R measurement , gotta cool it down,.

 

[laatsch55]

And the bulb stays bright...

 

[laatsch55]

Gotta get up early, goin to bed...

 

[derek92994]

Best entertainment I have had all day, looking forward to progress Lee

 

[laatsch55]

Glad to provide a respite from your trials and tribulations Darc!!

 

[derek92994]

Glad to provide a respite from your trials and tribulations Darc!!

Its interesting watching the specifics like what you test and the path of fault finding. I do that to some extent with my job, more so with upgrading my nak decks.

 

[mlucitt]

Glad to provide a respite from your trials and tribulations Darc!!

I am about ready to resume troubleshooting on my WOPL 400, but I need (4) of those RCA 66546 or RCA 410 drivers.

 

[Gepetto]

I am about ready to resume troubleshooting on my WOPL 400, but I need (4) of those RCA 66546 or RCA 410 drivers.

You really only need 2 Mark. The 2nd and 4th column starting at the transformer and ending at the output binding posts. These are the quasi columns. The first and third don’t care.

 

[laatsch55]

They went in the mail yesterday Mark. 6 of em..

 

[mlucitt]

They went in the mail yesterday Mark. 6 of em..

Thanks, I'll put them to good use.

Joe, I will populate 2nd and 4th and see what happens. Lee and I are on the dark side, just like back in the good old days.

 

[laatsch55]

Joe,

Pad 6L, 6R are at -23.80 volts with pad 12 voltage at -28.5....That with the variac at 100%...

 

[Gepetto]

with those readings Lee, looking more and more like you fried Q7. Have you checked C-E for short with your DMM?

 

[laatsch55]

Showing 2 ohms in either direction so .....I'd say so...

 

[Gepetto]

Showing 2 ohms in either direction so .....I'd say so...

There is a smoking gun...

 

[Gepetto]

Seems like Q10 may still be alive since it was fighting hard.

 

[laatsch55]

I believe so Joe, it got hot enough. Why did Q7L go? Zapped through the power supply?

 

[laatsch55]

Out of circuit , same result. Should I reattach the free end of R76 before applying power w3ith new Q7?

For some reason didn't check C-E in circuit, just B-C, B-E and reverse polarity...jeez..