JBL EON15, Введение и общая информация

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1) LED may be defective, and check traces around it.
2) Check reference voltage at pin 8 of U1 = –100mV, and for any short or open circuits
around U1.
3) With oscillator off, check that there is 0V DC at pin 1 of U2, if the voltage is greater than
0V, U2 may either be defective or have one of its input pins (2 or 3) disconnected (open
trace) from the rest of the circuit.
G) Peak Indicator Test
Set oscillator frequency to 100 Hz, and Volume control, R16 fully clockwise. Adjust oscilla-
tor level for 4V P/P on pin 1 of J4. Verify that Peak LED, D3, as well as Signal LED, D7, are
on. Turn volume control down and verify that Peak indicator turns off. If the above test fails,
check reference voltage at pin 4 of U1 = –730mV, also check for any short or open circuits
around U1.
A) Initial Setup
The easiest way to drive the EON PowerSub Main Board is to connect it to an EON
PowerSub Input Board. Interconnect both boards using a 6-pin cable assembly. Advance
Volume control on input board, R16 fully clockwise. Attach power transformer to J5.
Adjust bias control, R17, fully counter clockwise if at all uncertain about the bias adjustment
being correct. Connect the output to a 4ohm load. Connect generator output to input
board’s XLR connector. Generator output should be turned off.
B) Main Loop Test
M15V supply while slowly advancing Variac that is powering primary of power
transformer. Watch the input watt meter, as well as the input volt meter. Verify the following:
1. Excessive power not pulled. Slowly advance input power (Don’t allow +15V supply to go
higher than 16V). If power pulled is greater than 20W, before reaching 120VAC in, refer to
“Excessive Line Power Test”.
2. As you ramp up the input voltage verify that +/– 15V supply stays in regulation. If supply
is non-existent or excessive refer to “+/– 15V Supply Test”.
3. Check for the presence of +/– 48V at test points 1 and 8 (TP1, TP8). If low or nonexis-
tent refer to “+/– 48V Supply Test”.
Amp Assembly Trouble-shooting
EON PowerSub