JBL EON15 Скачать руководство пользователя страница 18 | Manualshive

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JBL EON15 Скачать руководство пользователя страница 18

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Measure the response at pin 1 of U3. Note in figure 3 above that the input voltage has not
been changed. (Voltage at pin 1 of J3). The other curve represents the response at the
output of the third section of the filter.

The third section is a low Q (Q equals about .7) high-pass filter at 33Hz.

Verify the peak frequency, 55Hz and the peak voltage 5.1V P/P. Also verify voltages at
20Hz, 30Hz, and 40Hz.

If the response is incorrect check values of C29, C30, C34, R56 and R57.

After obtaining proper response proceed to following section.

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Содержание EON15

Страница 1: ...oduct repaired with out JBL specified components may not meet the factory specifications The product war ranty may be voided by a repair using unapproved JBL components Test Equipment 1 Audio Precisio...

Страница 2: ...t is available for the M115 8 woofer Entire driver should be replaced 124 67001 00X NOTE To recone the EON woofers it is not necessary to disassemble the enclosure The woofer can be reconed from the f...

Страница 3: ...ompliance land and spider land with MEK or acetone 7 Remove tape from gap and clean magnet gap with masking tape and with MEK and a rag 8 Unpack recone kit and inspect for damage 9 Verify that the voi...

Страница 4: ...est Station 7 Air Gun and Safety Glasses Procedure 1 Record Model number Serial number Date code and compliant for warranty information 2 Lay the enclosure face down on a soft clean surface to avoid d...

Страница 5: ...00Hz If no buzzes are detected then test at 2V from 1 500 Hz to 20 kHz for full range operation and audio clarity It will be necessary to lift the baffle to expose the horn so listening tests can be p...

Страница 6: ...01 Verify resistance from pin 2 to pin 1 of U202 pin 3 of U202 to ground 10K If not check for opens and shorts around U202 5 Rotate Volume control counter clockwise while monitoring pin 1 of P204 Volt...

Страница 7: ...vel for 20V P P on pin 1 of P204 Verify that Peak LED D203 as well as signal LED D201 are on Turn volume control down and verify that Peak indicator turns off A Initial Setup The easiest way to drive...

Страница 8: ...to the amp is not clipped The amp input can be measured at the junction of R22 and C18 With 60V P P at the amp output there should be around 1 9V p P at the input to the amp If one or more of the abo...

Страница 9: ...ncy Power Amp Test F Supply Test 15V Supply Test Slowly ramp up Variac never allowing the supplies to exceed 16V Measure 15V and 15V supplies Both should be the correct value 5V If a supply is very cl...

Страница 10: ...to zero check for 1 collector to emitter short on Q17 2 incorrect value R49 3 shorted TS1 Thermostat should be open when cold and will close at 80 degrees C 4 reversed or shorted Z2 If voltage ramps u...

Страница 11: ...ny greater than 2 5VDC Measure resistance of R9 and R21 the correct value is 243 ohms If R9 or R21 value incorrect or if the voltage across these parts is excessive proceed to Voltage Amp Test If R9 a...

Страница 12: ...ssover from positive drive to negative drive This actually takes a small chunk sometimes only visible in distortion waveform out of the center of the output waveform This also causes some harmonic dis...

Страница 13: ...he characteristics of the waveform and then probe on both sides of C12 C12 is across the input to the current amp If the waveform visibly appears almost identical Same P P voltage same waveform shape...

Страница 14: ...s the output bias current and keeps it constant with temperature a Excessive power pulled from AC line This is due to excessive voltage across reference The range measure across C12 should be 1 7V to...

Страница 15: ...rify that voltage across R5 equals 870mV 20 If incorrect check Q4 for open or shorted elements Verify that the voltage at the emitter of Q3 is 6V If incorrect check Q3 and Q4 for shorts and opens Veri...

Страница 16: ...unction of the first filter section R63 R64 and C37 when this section is operating properly Sweep the oscillator frequency and note if the readings are reasonably close to the values indicated in the...

Страница 17: ...n of the filter The second section is a moderate Q Q equals about 2 high pass filter at 55Hz Because of the moderate Q the filter actually peaks The 55Hz Peak Verify the peak frequency 55Hz and the pe...

Страница 18: ...esponse at the output of the third section of the filter The third section is a low Q Q equals about 7 high pass filter at 33Hz Verify the peak frequency 55Hz and the peak voltage 5 1V P P Also verify...

Страница 19: ...urth section is a moderate Q Q is a little more than 1 low pass filter at 1 4Hz Verify voltages at 100Hz 1kHz 2kHz and 4kHz If the response is incorrect check values of R53 R55 C28 and C33 Reattach li...

Страница 20: ...tial If not close check for shorts surrounding pin 10 If no shorts are found replace U1 Verify that pin 9 reflects the output offset polarity The offset should be much greater than 1V If not look for...

Страница 21: ...pin 1 of J3 The curve below this line represents the transfer function of the first filter section R61 R71 and C44 when this section is operating properly Sweep the oscillator frequency and note if th...

Страница 22: ...curve represents the response at the output of the second section of the filter The second section is a moderate Q Q equals about 2 high pass filter at 1 9kHz Be cause of the higher Q the filter actua...

Страница 23: ...High Frequency Response EON Power15 and EON15P 1 230 33...

Страница 24: ...Low Frequency Response EON Power15 and EON15P 1 230 34...

Страница 25: ...from pin 2 to pin 1 of U2 pin 3 of U2 to ground 3 2k if not check for opened and or shorted traces around U2 5 Rotate volume control counter clockwise while monitoring voltage at the junction of pin...

Страница 26: ...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 al...

Страница 27: ...at the input to the filter pin 1 of J3 is about 2 7V P P If not check for shorts or open circuits around filter IC s U2A U2B and U1A E Excessive Line Power Test Verify the correct polarity and that no...

Страница 28: ...or possible shorts in the areas where these parts are All the above parts form the Current Amplifier Providing current gain Everything from Q10 Q12 and before form the Voltage Amplifier Providing volt...

Страница 29: ...current amp Q3 Q1 Q7 and Q8 the bias reference needs to have around 2 4V 4 drops across it to turn on all four transistors in the current amplifier The range of adjustment is very small Between 1 7V...

Страница 30: ...Low Frequency Response EON PowerSub 40...

Страница 31: ...400Hz 2 Verify that voltage at output pin 1 of J1 800mV P P 100mV 3 Verify presence of 400mV P P 50mV at pin 1 of U1 4 Remove oscillator connection to XLR input Verify resistance from pin 2 of J2 to p...

Страница 32: ...a 7 pin cable assembly Place the input board in Line mode SW1 out Advance volume control on input board R25 fully clockwise Attach power transformer to J7 Connect the low frequency output to a 4 ohm l...

Страница 33: ...ne or more of the above tests fails proceed to High and Low Frequency Power Amp Test If the oscillator is adjusted for 4 9V P P at pin 7 of U4 the voltage at the input to the filter pin 1 of J6 should...

Страница 34: ...s the power consumption should go to normal idle level less than 40W if the load is removed If it does not check for shorting from the output pin pin 3 to either the 31V or 31V supplies If not shorted...

Страница 35: ...High Frequency Response EON Power10 45...

Страница 36: ...Low Frequency Response EON Power10 46...

Страница 37: ...nnel 1 Do not plug anything to the Patch nor to the Phone Jacks Adjust volume control R47 Master and R48 Channel 1 fully clockwise and all EQ controls flat at center detented point Verify that the vol...

Страница 38: ...he output at pin 1 of J1 is approximately 9 3 dBu Turn High Mid Frequency EQ control fully clockwise and verify that pin 1 of J1 is now approximately 21 2 dBu Turn same knob fully counter clockwise an...

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