Data Stream Dissector (DSD) Kit Troubleshooting Tips last revised 12/31/93 So you've built the kit and it doesn't work :-( (See the troubleshooting tips later in the document if the DSD works, but has intermittant problems.) By far the most common error is to not install ** all ** of the jumpers indicated on the diagram, J1-J9 and 18 unlabeled jumpers (including one omitted on the layout diagram for the non-isolated coaxial input, see the errata document, and the easy-to-miss ones under C2 and to the right of U4). Another common error is to not properly select the input digital stream on the DSD. Another common error is to not select the digital input on the recording deck! Verify that your digital components can dub from one to another without the DSD, which will make sure that the decks are set up properly when the DSD is in circuit. In order to troubleshoot the DSD effectively you MUST have a digital source and a DAT deck, minimum, and preferably two decks, one with both coaxial and optical out and one with both coaxial and optical in. Take a voltmeter and verify that the power supply is producing 5V (as indicated in the assembly directions) before continuing with the rest of the troubleshooting. If 5V is not being produced, check the external unregulated power supply and make sure it is sending 6V-18V. Remove the PAL using a vacuum desoldering tool and/or desoldering braid. Install an empty PCB socket instead. Data Stream Dissector (DSD) Kit Troubleshooting Tips (page 2 of 4) Here is the PAL pinout: +---------\ /---------+ | \ / | | ----- | fsync | 1 24 | Vcc | | cbl | 2 23 | fc0 | | csb | 3 22 | fc1 | | sel0n | 4 21 | n4 | | sel1n | 5 20 | n3 | | sel2n | 6 19 | n2 | | sel3n | 7 18 | n1 | | bypn | 8 17 | n0 | | dain0 | 9 16 | daout | | dain1 | 10 15 | rxp | | dain2 | 11 14 | txp | | GND | 12 13 | dain3 | | | | `---------------------------' Data Stream Dissector (DSD) Kit Troubleshooting Tips (page 3 of 4) Here is the PAL hookup: " " +--------------+ +--------+ " | | | | " | | | | " | PAL | | CS8412 | " | | | | " | | | | " in 0 -----|>--------| dain0 rxp |-----| rxp | " in 1 -----|>--------| dain1 | | | " in 2 -----|>--------| dain2 | | | " in 3 -----|>--------| dain3 | | | " | | +--------+ " | | " +--------+ | | " | | | | " | CS8402 | | | " | | | | " | | | | " | txp |-----| txp daout |------+----|>--- out 0 " | | | | | " | | | | +----|>--- out 1 " +--------+ | | | " | | +----|>--- out 2 " | | | " | | +----|>--- out 3 " +--------------+ " Data Stream Dissector (DSD) Kit Troubleshooting Tips (page 4 of 4) When I refer to pins, I'm talking about the socket holes where the PAL used to be. Direct connect one of the inputs, coming in on D0 pin 9, D1 10, D2 11 or D3 13 to the digital out DOUT pin 16. Play a 44.1 khz source on the device connected to the input. Verify that the 44.1 khz source is coming out correctly on each output. Then change to a different input, and repeat for each input. At this point you have verified that the input section and output section are working properly. Now reconnect the input you are using (pin 9, 10, 11 or 13) to RXP (pin 15). (DOUT pin 16 shouldn't be connected to anything.) Play a 44.1 khz source on the device connected to the input. The green LED should immediately light, indicating that the 8412 is receiving the data stream correctly. If this doesn't happen, suspect a problem with your 8412 and/or the connections to it. (The LED might also be screwed up, or the transistor or resistor connected to it. Meter 8412 ERF pin 25 directly. If it is OFF (GND, 0V) (i.e. no error) but the LED is not on then there is something wrong with the LED lighting circuit.) Ground FC0 pins 22 and FC1 23 by tying them to GND pin 12. Set all DIP switches ON. Connect DOUT pin 16 to TXP pin 14. Play a 44.1 khz source on the device connected to the input. Verify that the 44.1 khz source is coming out correctly on one output. If this doesn't happen, chances are, in roughly descending order of possibility a) bad connections on the 8402 b) bad connections between the 8412 and 8402 c) bad 8402 chip d) bad 8412 chip. If you reach this point, reinstall the PAL and verify correct operation. If all of the above tests work, but when you have the PAL installed the device does not work, doublecheck that you have the DIP switches set appropriately on the device (see the user's guide). If the device still does not work, you've got a bad PAL. (Most common reason for a bad PAL/GAL: hooking up the external power supply to the DSD with the polarity reversed.) If you have problems with the destination deck occasionally losing lock (i.e. digital data flow interrupted): It ** is ** important that the shield side of the coaxial cable is connected to the side which is grounded on the PCB and the center conductor is connected to the signal. This must be the case for all coaxial inputs and outputs! I have also seen this when my clothes dryer and / or power amp were turned on / off. They were on the same circuit as my DSD and dipped the 120 VAC enough that the external power supply transformer went below the minimum voltage. (In the case of the power amp, it seemed to be more due to the power line to the amp running right next to unshielded low resistance RCA cable which i was using (bad!) for coaxial connection. Probably EMF screwing up the bits. Always use the proper 75 ohm coaxial cable for digital interconnections.)