Thanks?Mike for the reply. I have checked a lot of the IC's and they do have 5 volts VCC on them but will check them all. Maybe one does not. The NORM/EXT switch on the back does not do anything. they display is black and it stays that way. I will let you know what I find out.
On Fri, Dec 20, 2024 at 8:05?PM mike bryce via <prosolar=[email protected]> wrote:
Jim
do you have +5 volts on the VCC pins of the ICs? Sure sounds like you¡¯re not getting power to the board.VCC, as you might well know, lives on pins 14 and or 16 of MOST ICs.
Service manual will be your friend.
withe the NORM/EXT set in EXT, the display should be on, and showing 00000?
mike wb8vge
The Heathkit Shop
On Dec 20, 2024, at 1:54 PM, Jim Harris via <radiove1rb@...> wrote:
I don't post much but I do read all the messages but now I need help. The DR7 board in my Drake TR7 has no digital display at all, no periods or digits, just black. I have checked the 5 volt regulators and they are fine. I have cleaned the pins and sockets where?it plugs in and also the top board ones the connectors plug into. I have visually checked the board for bad solder joints but have not seen any. I have checked the STORE switch and cleaned that and also the NORM/EXT switch on the back. All oscillators are working as I have checked them all and done an alignment of them. I have a jumper board installed but have not tried to see if it is receiving but I don't think the calibrator is working or I can't hear it. I wonder if anyone else has had this trouble with a DR7 board? Any hints and suggestions would be appreciated.
