I would start with a removal of the DR-7 board, then SPARANINGLY apply DeOxit to each pin, and then reseat the board. Then I would see what happens and start making voltage and signal checks.? Too, it might be informative to see if the frequency actually changes, or if it is just the display.
-----Original Message----- From: J J Connelly <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Sent: Thu, 10 Jan 2008 11:33 am Subject: [drakelist] DR-7 Display Problem "J J Connelly" <[EMAIL PROTECTED]> made an utterance to the drakelist gang? ----------------------------------------------------------------------? Hello all,? the digital display on my TR-7 has decided to go crazy.? ? The digits have begun to change at random and frequently go completely? blank. This problem exists whether switched to either an INT or EXT source;? it is intermittent and the display can be made to behave for a short time if I? play around with the connectors at P1 and P2 or if I move the body of the DR-7? very slightly (and carefully) or if I switch the rig off/on.? ? At all times the actual frequency is stable and the full coverage functions? of the DR-7 are OK.? ? I'm a complete rookie when it comes to digging into this kind of circuitry, but here's? where I've reached...............? Checking around on the DR-7 with meter and scope, supply voltages are OK;? the scope shows the output from the both INT and EXT amplifiers on the output side of? U9011(pins 2 and3) and switching correctly.? ? I suspect U9014 may have gone faulty. The scope shows the 500Khz at pin 14,? but with an intermittent output. If there are pulses coming out, the display is fine,? else it's blank. I can't figure out what causes the change other than the device has? faulted.? ? Am I on the right lines or is there somewhere else I should be looking?? Any ideas? most welcome.? ? By the way, my version of the DR-7 has 2 x 1N4148's on the output from U9014? and is different from the diagram in my manual.? ? ? Many thanks,? Joe Connelly? GM3RGU? ? ? ? ? ? ----------------------------------------------------------------------? Submissions: [EMAIL PROTECTED] Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body? Hopelessly Lost: [EMAIL PROTECTED] - help in body of message? Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net? ----------------------------------------------------------------------? ________________________________________________________________________ More new features than ever. Check out the new AOL Mail ! - http://webmail.aol.com
