Tag Archives: mm2114

Wavetek 172B Signal Generator: a heavy 00000000

This Wavetek has been part of an Army sale a while back, and I had used it for some project, but in recent years, it started to gather dust – it is a nice units but pretty heavy and I don’t want to hurt my back.
When I switched it on recently, it showed all “0000000”. The keypad is responsive and a beep sounds with any key pressed, but there is no reaction or output. Sure this can be fixed but I am not a Wavetek expert and all hands full with large gardens and other projects. So I sold the Wavetek to Ulrich Prinz DC3AX who kindly fixed it and shared the repair pictures and details below. Also I have the EPROMs archived in the Manuals Archive in case you need it.

Turns out that the keyboard has an independent processor, but the main CPU board is not initializing properly, normally, it needs to send a string “Wavetek 172B” to the display with self test completed, but the CPU doesn’t do anything.

The sockets on these boards are nowhere near Hewlett Packard quality, but single spring low cost IC sockets that are prone to aging and contact issues. The most critical ones around the PROMs were replace with precision contact IC sockets.

M2114 4k static RAMs, these are known to fail at times, so they were replaced.

Finally, a test, and it boots up and runs through the self test no issues. A marvelous repair because CPU boards can be tricky to fix – let’s hope for long and trouble-free service of the unit at its new owner!