Re: Smoke damage 7704A


Hi Tom-
i have had to do this numerous times on pieces of equipment involved in fire/smoke over the years- mostly 50kv and 500kv supplies. took them apart, 409 ( had an oily residue on a few)  or something that dissolves the carbon/smoke residue, scrub with brush if at all possible, hose it down, repeat as needed. finally dunk/ rinse it in IPA and blow it off, repeat couple of times .  after a good air dry like 24 hrs, then put it in an oven for several hours ( overnight) between 100 and 150 F. reassemble an have had full recovery....some of theses were really bad. in fact they were black! could measure the resistance across the boards!
I always worried about arcing in HV xformers but cleaning worked.... In fact i know a couple are still working just fine after 10 years.
try to avoid getting too much water/liquid in the xformers if possible and no hi pressure spray..most everything else seems to hold up ok.... now faceplates/lettering your mileage will vary- test first.
I have to rebuild the stuff I always figured what do I have to loose?
Hope this helps

On 7/14/21 12:18 PM, Thomas Voshell wrote:
I have a 7704A that was damaged in a house fire. The scope was in a closet upstairs and everything outside of the closet was either melted or burned. There is significant smoke residue on the outside of the covers and possibly some overspray from fire hoses. I have not yet taken the covers off; no knobs frame plastics are melted on mainframe or plug-ins which look externally smoked up. (7a18, 7a26, 7b50, 7b51). I believe powering it up would be foolhardy as carbon conducts. My inclination is to completely disassemble the frame and wash with water the electronics and allow to air dry. Due to age I am worried about old plastic flat cable connectors and the acquisition to display unit connector. The CRT connector and the HVPS also worry me.

Does anyone have any suggestions/comments/insights/experience WRT this situation?


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