|Re: restoring HP25C - more pictures|
Message #10 Posted by Alberto Fenini on 25 Nov 2012, 7:56 a.m.,
in response to message #9 by aj04062
Here we are,
I have used this vinegar solution : 50% vinegar, 50% distilled water and some salt.
I left the pcb in a glass, in vertical position submerged for two minutes, then rinsed with distilled water.
I did the treatment twice, but there are two things that I don't understand so i'm asking for your help.
The leftover from battery leakage has been almost completely removed, but still some micro spots are there as can been seen in this macro :
Should I do it again one more time ?
I have noticed that the treated parts gets kind of matt, if you look at the vertical pin or the soldered chips these are not shiny as other metallic components.
Is this because I have used too much vinegar ?
Or may be is because I have left the PCB too much time in the solution ?
Following Adam instruction, I have removed the label, cleaned all the old glue and using a similar adhesive re-positioned, now the label is back in place like new, thanks Adam !
And this is, for now the result :
Now, I'd like to spend more efforts on the faceplate, till now I have used a gentle soap and then a wax that contains carnauba, I had used this in the past with success on an HP45 faceplate.
I know however that better results can be obtained using the Tamiya Flat Clear spray, which I have used once also on a Classic.
Shoud I want to use it on this Woodstock, how can I protect the keys ???
Thanks for help and all the tips.
One last thing, since I was curious about the fact the most of the lettering was in good condition, but the "Continous Memory" writing was gone, I dropped a line to the seller, and this is waht he wrote me this morning :
You are right I remember the italic or script continuous memory, I thik I removed it as it looked added on. The manuals were an instruction book and book of programs, They were lost in a house fire. Cheers John