Orion HCCA 275G4

[Itsme]

Hey Perry, Sent you 4 email's. They were pretty good size even zipped. Hope you have a fat pipe. (Broadband) or (T3).

 

[Perry Babin]

I'm on fiber so that's not a problem. I haven't received them yet so they may have been lost. If they were over 25M per file, Yahoo may have blocked them.

 

[Itsme]

Do you put the underscore in between your last and first name on your email address?

 

[Perry Babin]

The underscore is part of the address. You should be able to click on it and send the email without having to type the address.

 

[Itsme]

thats how I did it so hopefully you should recieve 4 emails from me. They were 15-17 mb each.

 

[Itsme]

I just sent a test email to you to see if it goes through.

 

[Perry Babin]

Measure the DC voltage on each side of C42 and C49 (near the RCA jacks). Use the secondary center tap for the reference (black lead).


C42
Round pad:
Square pad:

C49
Round pad:
Square pad:

 

[Itsme]

Hey Perry, just checkin if your there tonight? I'm taken another go at this.

 

[Perry Babin]

Did you measure the voltage on the 4 terminals of those capacitors?

 

[Itsme]

Measure the DC voltage on each side of C42 and C49 (near the RCA jacks). Use the secondary center tap for the reference (black lead).


C42
Round pad:
Square pad:

C49
Round pad:
Square pad:

Both round pads were 13.1 volts
and the square pads started out at 1.7 and slowly raised to 3.2 volts within a couple of minutes I had it on.

 

[Perry Babin]

Pull the two muting transistors to see if the voltage on the output goes to 0v DC.

 

[Itsme]

Sorry not sure which are the muting transistors?

 

[Perry Babin]

2N5639?

 

[Itsme]

2N5639?

I think those are the ones I replaced because they popped awhile back. I will pull them and check voltage.

 

[Itsme]

Ok I pulled them. where did you want me to test? If you were talking about the speaker out's I'm still getting 30 volts DC on both channels.

 

[Perry Babin]

There are two resistors. One end is connected to the capacitors you measured voltage on (they are next to the ceramic disc capacitors marked 101j). The other end probably goes to the muting transistor. Pull one of them in one channel to see if the DC goes away.

 

[Itsme]

There are two resistors. One end is connected to the capacitors you measured voltage on (they are next to the ceramic disc capacitors marked 101j). The other end probably goes to the muting transistor. Pull one of them in one channel to see if the DC goes away.

Nope - Still voltage

 

[Itsme]

Hey Perry, When I first started workig on this amp I replaced the tl494cn and a couple of caps next to it because they looked hot. Would the problem I am having have anything to do with one of the legs not making connection or a cap in backwards?

 

[Perry Babin]

With the resistor out of the circuit, do you still have the following voltages on the pins of the opa134?


Pin 1:.12.8
Pin 2:.1.4
Pin 3:.13.1
Pin 4:.-13.2
Pin 5:.0
Pin 6:.12.1
Pin 7:.13.2
Pin 8:.12.8

Does one end of the resistor you pulled go directly to pin 3 of the 134?

 

[Itsme]

I still have the 2n5639's out, is that ok to measure what you want?