Need help with Nicolet 4094 Oscilloscope

[chill4]

I am trying to resurrect a 1987 Nicolet 4094B digital oscilloscope with a 4175 plug-in in the 1st (left) bay and a 4570 in the 3rd (right) bay. It has been in storage for 15-20 years and worked fine before being stored. It powers up fine with a single beep and the 4094 seems to be working as it should. When both plug-ins start-up they remain in a locked state with random indicating lights on. The manual addresses this state and indicates that it is associated with the storage of settings from previous operations that somehow leaves it in this error state. The reset is accomplished by powering off and then powering back on while simultaneously depressing the 4 delay buttons on the plug-in. I have tried this countless times with no success. I have disconnected the plug-ins and even removed them from the chassis thinking it might erase any memory but no luck. I have searched the web and this forum with no success.
I am not well educated/experienced with electronics so I apologize in advance for my lack of understanding a highly technical response. Any suggestions are appreciated.

[dc8frate]

Hello chill4,  Have you tried a power on without the plug ins connected?

[chill4]

Hi dc8frate,
I don't think I did. I pulled each plug-in and powered up with the other plug-in installed but I don't think I tried powering up the 4094 without either plug-in installed. I'll give it a try. Thanks.

PS. I am new to the forum. Did I post this in the right place? Also, sorry I didn't reply sooner. I did not know you replied, thinking I'd get an auto email when someone did. Thanks again.

[chill4]

I disconnected both plug-ins and then powered up the scope. Put them back in both singularly and together. Still the same problem in each scenario.

[donlisms]

I don't know if this will help you, but if you search for "Nicolet 4904 operation manual", you will find the 4094 manual -- and yes, the model number is wrong on the website.  Joe seems to have collected quite a bit of historical data on this and other fun things, and programs that will run on it, and so on and so forth.

My only other comment is that... generally speaking, with older equipment, it's very often the capacitors that go bad, and power rails and such go bad internally, and things stop working in various ways.  I suppose just sitting there long enough could put it over the edge.  The fix is often pretty easy, for those with the intestinal fortitude -- replace the bad capacitors.