+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Sat, 17 Mar 2001 10:49:56 -0700 From: Gary L Surrency Subject: [Elecraft] K2 ELE display at power up Hello Pierre and K2 'ers, When the ELE message occurs, the MCU (U6, Control Board) is held up waiting for completion of an input from one of these circuits, and it stops at the ELE display a power-ON. These types of problems are usually related to a poor connection or a short to ground on one of the following circuits: /BANK1 /BANK2 /SP RD /MIC RD V POTS Any poor or missing solder connection on pots R1, R2, R5, or the 1N5817 diodes will cause this problem. Also check for a reversed diode at D4-D6. The wrong resistor at R13 in the Mic Config circuit will cause this, as will a stuck Mic Up/Dwn button or a wiring error in the Mic Up/Dwn circuit, Mic Config header, etc. Make sure Q3 (if installed) is a 2N3906, not a PN2222A. Note that the 100K pullup resistor at R14 must be installed and making good contact, or these circuits will not be in the correct idle logic state (HI). The TPIC6B595 IC's at U3, U4 are CMOS devices, and are subject to damage from ESD. Be sure to wear a ground strap and use precautions to prevent static electricity damage to these IC's. I have had to replace a number of them that had failed. See if these IC's are not reversed in the PCB too. A failed IC at U3 or U4 will cause the ELE problem too. A lot of times a very close visual inspection of the Front Panel PCB will reveal the problem. You can use an ohmmeter to check for shorts to ground on any of the circuits mentioned above. Although the readings may vary from the resistance check table in the manual because of ohmmeter differences, none of these circuits should be grounded or open (infinite ohms). A stuck pushbutton switch, or a switch pin bent over and not inserted through the PCB on one of the switches is another common Front Panel problem. If the firmware version shows up each time the rig is turned ON (currently "1.06f 1.02"), then a problem exists in the pushbutton matrix. Check around each switch pin, and at U2, RP1 (is it reversed?), etc. The firmware display should only occur when a pushbutton is manually held down during power-ON. Use care when assembling the Front Panel PCB, as it is difficult to troubleshoot without a good understanding of the logic circuit. Use a minimum amount of solder, the proper amount of soldering iron heating time, and be careful to not cause short circuits or leave anything unsoldered. Clip all leads closely to the PCB, and mount the components carefully as described in the K2 manual. Look at the FP PCB when you complete it, and be sure everything is A-OK before installing it. This same idea applies to all the PCBs in the kit. - -- 73, Gary AB7MY ========= gary at elecraft.com (please use this address to reply, NOT gsurrency at juno.com) Elecraft Technical Support ++++++++++++++++++++++++++ Date: Fri, 26 Oct 2001 05:41:33 -0000 From: "Pierre Fillinger" Subject: Re: [Elecraft] InFO 201....... HelloPer, I have been battling for several days with the problem. I had a great support from Gary. below the answer which helps me to troubleshoot my K2. 73, Pierre de F5MOG +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Sat, 17 Mar 2001 10:49:56 -0700 From: Gary L Surrency Subject: [Elecraft] K2 ELE display at power up Hello Pierre and K2 'ers, When the ELE message occurs, the MCU (U6, Control Board) is held up waiting for completion of an input from one of these circuits, and it stops at the ELE display a power-ON. These types of problems are usually related to a poor connection or a short to ground on one of the following circuits: /BANK1 /BANK2 /SP RD /MIC RD V POTS Any poor or missing solder connection on pots R1, R2, R5, or the 1N5817 diodes will cause this problem. Also check for a reversed diode at D4-D6. The wrong resistor at R13 in the Mic Config circuit will cause this, as will a stuck Mic Up/Dwn button or a wiring error in the Mic Up/Dwn circuit, Mic Config header, etc. Make sure Q3 (if installed) is a 2N3906, not a PN2222A. Note that the 100K pullup resistor at R14 must be installed and making good contact, or these circuits will not be in the correct idle logic state (HI). The TPIC6B595 IC's at U3, U4 are CMOS devices, and are subject to damage from ESD. Be sure to wear a ground strap and use precautions to prevent static electricity damage to these IC's. I have had to replace a number of them that had failed. See if these IC's are not reversed in the PCB too. A failed IC at U3 or U4 will cause the ELE problem too. A lot of times a very close visual inspection of the Front Panel PCB will reveal the problem. You can use an ohmmeter to check for shorts to ground on any of the circuits mentioned above. Although the readings may vary from the resistance check table in the manual because of ohmmeter differences, none of these circuits should be grounded or open (infinite ohms). A stuck pushbutton switch, or a switch pin bent over and not inserted through the PCB on one of the switches is another common Front Panel problem. If the firmware version shows up each time the rig is turned ON (currently "1.06f 1.02"), then a problem exists in the pushbutton matrix. Check around each switch pin, and at U2, RP1 (is it reversed?), etc. The firmware display should only occur when a pushbutton is manually held down during power-ON. Use care when assembling the Front Panel PCB, as it is difficult to troubleshoot without a good understanding of the logic circuit. Use a minimum amount of solder, the proper amount of soldering iron heating time, and be careful to not cause short circuits or leave anything unsoldered. Clip all leads closely to the PCB, and mount the components carefully as described in the K2 manual. Look at the FP PCB when you complete it, and be sure everything is A-OK before installing it. This same idea applies to all the PCBs in the kit. - - -- 73, Gary AB7MY ========= gary at elecraft.com (please use this address to reply, NOT gsurrency at juno.com) Elecraft Technical Support ++++++++++++++++++++++++++