Hello, I need some help tracking down the source of my problem with my 2465B (SN B055XXX). Here is the issues: No trace, needed to turn up Grid Bias to get display, Test Fail 05 44 (ADD LED On), after A/B TRIG is pressed read-out is present with flashing dots across top and bottom of screen (2 rows top and bottom). Replaced A5 board from good scope and everything works fine. Defective A5 - Intensity Control has no effect. -1.25V and 1.36V are very low. Jumping J504 to DIAG (Pins 2&3) causes Voltage to return and trace but no control. I previously replaced all Caps and Dallas Chip. U2101 - DAC pins 18 & 19 low output signal (should be over 1V, getting about .25), which feed U2501 (CD4051). Also, TP9 low signal compared to good board. Since DAC output was low I replaced DAC with a DAC312. Problem still exists. All PCB traces checkout ok.
Any suggestions would be greatly appreciated. Thanks in advance.
Any suggestions would be greatly appreciated. Thanks in advance.
