HP-65 1603S03518 in search of advice

[albertofenini]

Hello everyone

we have purchased this unit mostly for parts, knowing it was not working

however, since it's partially working we would like to try a restoration

when opened it has revealed a light corrosion on the cpu board as well in few other places

We believe that the display behavior it's possibly due to the corrosion

However, since last time we cleaned an HP-65 board submerging it in the water and vinegar solution we have damaged the hybrid we are now looking for some advice on how to clean it

Last time we used how water and vinegar, so may be the damage was mostly due to the temperature that the mixture itself, however any advice is very welcome !

Thanks in advance and take care !!

Pictures can be seen here : HP-65 1603S03518

[teenix]

Maybe not submerge the board completely. A toothbrush can help scrub the board, although not under components. The seal on the top case of the hybrid may have lost its integrity over the years.

cheers

Tony

[albertofenini]

Thanks Tony,

we followed the suggestion and this time we ended with a working board
If someone is interested in seeing the process, there are some pictures here :
HP-65 1603S03518

We haven't rebuild the coupler because it appears solid, and since the unit
reads and writes we didn't want to molest it more than what was necessary

However, like almost all the units we repaired, after the first reading the two
o-rings tent to separate, any idea on how to glue them together ? with glue would
work better ?

thanks for help and take care !

[teenix]

I apply a drop of super glue onto a scrap of paper or whatever is handy. Then using a fine implement like a thin wire or a pin, dip the end in the drop and use this to smear the glue around the metal wall of the drive gear. I have a hollow piece of metal tube that I push a single o-ring on with to keep it square on the shaft.

I then apply another tiny amount of glue to the side of the installed o-ring and add the second o-ring like the first.

Applying the glue to the side walls gives greater adhesion and it still easy to remove if necessary.

Too much glue risks it dribbling where it shouldn't be.

I haven't had any separation problems as yet.

cheers

Tony

[albertofenini]

Thank you very much, we have tried on an HP-67 and it worked fine !!