JBL EON 612 Schematic Request

[tip29]

Hi all,

Does anyone have schematic for JBL 612 Power amp/ Power supply module? 5046347

Thanks.

[Kismet]

Is this ?

[HutchAmpMan]

[ATTACH=CONFIG]49312[/ATTACH]
Is this ?

Do you have this as a PDF or complete drawing? The bottom is cut off on this one.

[sugeda]

Similar

[vintagekiki]

sugeda

[jeffremus]

What is the most common failure. Mine is looking like the +-15 supplies are dead

[J M Fahey]

Sadly no such thing as "common failures", youŽll have to troubleshoot that supply meaning youŽll have to analyze how it works, deduct expected voltages and measure whether they are there or not.
Only then you can reasonably guess what parts are failing.

Do not start replacing parts at random, that does more harm than good and generally fails. .

Following schematic from post #2 , transformer windings #14 and 16 supply some lowish voltage (which you cant measure,we have 100s of kHz there) but which after rectification give you what I guess is around +/-25Vdc across C60-C64 ... measure there.

That voltage feeds regulators U4 and U5 and after those you MUST have +/-15V

Measure there loaded and unloaded, to check whether itŽs regulator failure or shorted load is clamping them down.

Post measurements/results.

As you see, random parts replacement leads you nowhere.

[doctor]

A small note.
The voltage values of a signal with a frequency of hundreds of kHz is easily measured using a scope. One just need to look at the distance between the peaks of the signal and correlate it with Volts/Div setting of the scope. Get the voltage peak-to-peak. From here one can easily calculate the Vmax and Vrms, if need.

[Dynamic]

Check Diodes D5 and D6 nested between the four large Electronic Capacitors. While you have the four capacitors removed check them as well.