Phonic 740

[bramley]

Anyone have a service manual / schematic for the Phonic power pod 740?

I have been given just the mixer section and thought it'd be fun to power it up and see what gives.

[doctor]

Anyone have a service manual / schematic for the Phonic power pod 740?

I have been given just the mixer section and thought it'd be fun to power it up and see what gives.

Service manual is too large (>25MB).
See attached contents, decide what you really need and send me your request.

[bramley]

Thanks! I really just need the pin configuration for the multiway connector between the mixer & amp section.

[Roxtech]

Howdy Doc,

I've got a 740D here that's randomly popping op-amps at switch-on. Very weird problem. The supplies are rock solid at +/-15v on a 'scope and I've seen no over-shoot at switch-on.
Any chance of sending me the whole manual??
Failing that, then just the schematics of the mixer sections and the power supply will do. Come to think of it, the +/-15v supply seems to originate from the power amp board, so maybe that would be handy too.

Much appreciated,
A.

[doctor]

Howdy Doc,

I've got a 740D here that's randomly popping op-amps at switch-on. Very weird problem. The supplies are rock solid at +/-15v on a 'scope and I've seen no over-shoot at switch-on.
Any chance of sending me the whole manual??
Failing that, then just the schematics of the mixer sections and the power supply will do. Come to think of it, the +/-15v supply seems to originate from the power amp board, so maybe that would be handy too.

Much appreciated,
A.

“Randomly popping op-amps at switch-on “ - I’m not sure I understand your meaning. Did you check op-amps outputs by scope?

[Roxtech]

When the unit first came in for repair, the +/-15v rails were pulled down to about 3v. Several op-amps were already burnt. They had gone up in smoke. They had blown. Fried.
After I removed the burnt op-amps, the power rails went back to +/-15v, but some of the other op-amps still burn when I switch on - all of the outputs of the remaining op-amps are pulled high. It looks like I will have to replace ALL of the op-amps on this mixer .

I suspect that maybe a nearby lightning strike (not a direct strike) may have induced high voltages in whatever cables were connected to the inputs, and may have over-loaded any protection circuitry?

[Roxtech]

I still haven't got to the bottom of this one.....
Sans schematics, I've discovered that there's something very funny going on with the earth connections. Taking all of the pcb's out of the front panel solved the problem of ICs blowing randomly. The cause seems to be that one of the earths is pulled down to -15V (it's a bit of a battle trying to beep this out with a meter.) I'd REALLY appreciate schematics if anyone can get them?

Rgds,
A.

[Steve L]

If you send me a PM with your email address I will send you the service manual with schematics.

The file is too large to post here. (6.7M)

Steve