harman/kardon | Service Bulletin |
Service bulletin # 9604 rev1 - October 1998 | This is considered a Minor Repair |
To: All harman/kardon Service Centers |
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Models: FL8300 |
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Subject: Digital Output Level |
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The Digital Interface Standard recommends D/A converters have a minimum Input sensitivity of 200 mV.
In early FL8300 production units, the Digital Output level was 240 mV 10% peak to peak. Based on our research, we found that some D/A converters require more than 240 mV for intermittent free operation.
In the event you receive a FL8300 from a consumer with the a complaint “Intermittent Sound from External D/A converter”, check the serial number in the table below.
If the FL8300 has a serial number higher than indicated in the table below, connect a properly working D/A converter to the Digital Output and verify interruption free operation. Also confirm the Digital Output level of the FL8300 is 500 mV 10% Peak to Peak. If the FL8300 passes these two tests, advise the customer to have their external D/A converter and connecting cables checked.
If the FL8300 has a serial number lower than indicated in the table below, perform the following modification:
1)With the unit plugged in and turned on, push the “open/close” button to extend the drawer fully; then turn the unit off and unplug it.
2)Open the top cover (6 screws).
3)Remove output board PCB3 from the rear panel (4 screws). This board can be pulled back and modified without completely removing it from the chassis.
4) Locate resistor R901, it may be a 680 ohm resistor or a jumper wire; replace in either case with a | 0.47 |
uf capacitor h/k part# |
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5)Locate R903 and change from 680 to a 4.7k resistor h/k part # 3029472970.
6)Connect a 75 Ohms cable to the digital output jack. Terminate this cable with a 75 Ohm load; connect an oscilloscope to the 75 Ohm termination resistor. While playing a CD, confirm the output of the signal is now 500 mV 10% peak to peak.
7)Reassemble the FL8300 and test all functions.
Model | Serial number | Serial number | Status | Action |
| 120V | 230V |
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FL8300 | May have low digital | Replace R901 with 0.47 uf mylar | ||
| to | to | output for some | capacitor h/k part# |
| applications | Replace R903 with 4.7k ohm resistor | ||
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| h/k part# 3029472970 |
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FL8300 | Factory Installed * | NONE REQUIRED | ||
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*Factory modification of the FL8300 starting with the serial numbers indicated in the above table consisted of: R236: 1k Ohm
R901: Jumper or 680 Ohm
R903: Changed from 680 Ohm to 4.7k Ohm.
Digital output level into 75 Ohms: 500 mV 10% peak to peak.
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