| Christer |
I haven't used my scope for many years and there seems now
to be some problems with oxide on the switches. I suppose
the best way to fix this is to use some cleaning spray. The
question is, are there any such sprays I should avoid? I don't
want to take any risks of making things worse.
Sprays available locally include:
CRC 5-56 (useful for most things, but not here, I think)
PRF 6-68
Chemtronics Pow-R-Wash PR and CZ
Electrolube EML
CRC Elektro 2-26
Kontakt Chemie Gold 2000 |
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| yeti |
| You should use something like tuner spray, no contact cleaner. |
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| Christer |
| quote: | Originally posted by yeti
You should use something like tuner spray, no contact cleaner. |
What is that? All the sprays I found in the Elfa catalogue are
either labelled as contact cleaner or anti-corrosion. Do you mean
they could be harmful? |
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| peranders |
I used to use a spray which was very easy to evaporate (like ether, petrol etc.), very effective and left no marks at all...and expensive. I have totally forgot the name but it could have been some Electrolube product.
Have you tried to "exercise" the switches? May often help. I'm very skeptical to fluids with some "oil" in. Tends to attract dirt with time and make things worse. |
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| Christer |
| quote: | Originally posted by peranders
Have you tried to "exercise" the switches? May often help. I'm very skeptical to fluids with some "oil" in. Tends to attract dirt with time and make things worse. |
Yes that helps, but I am not sure it is possible to get rid of it
entirely that way. Maybe I shoud try method harder first. I am
also sceptical to the sprays, but I thought it might be necessary
in this case. |
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| csd |
| I have used Chemtronics Pow-R-Wash for years and have never had any long-term problems at all. It is non-conductive, evaporates quickly, and has solved most (not all!) of my problems with switches and pots. |
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| mrfeedback |
Hands down, Caig Deoxit.
Eric. |
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| peranders |
| quote: | Originally posted by Christer
Yes that helps, but I am not sure it is possible to get rid of it
entirely that way. Maybe I shoud try method harder first. I am
also sceptical to the sprays, but I thought it might be necessary
in this case. |
If your oscilloscope has gold plated contacts and the gold is worn out your hope is also out. Harder (or even impossible) to make it work like before. |
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| Christer |
Per-Anders,
I'm pretty sure it is an oxide problem. Using the switches
improved things almost immediately. I havn't opened the scope
yet, though, since I wanted to buy some spray first to have
handy. I have never had to open it before either, since it always
worked well, but now it has been out of use for quite some
years. Maybe I should have a look inside before buying any
spray.
Csd,
Thanks for your reply, I might try Pow-R-wash then, it is one of
those I was considering from reading the descriptions.
Eric,
I'm sure Caig Deoxit is good if you recommend it, but I'm afraid
it may a bit difficult to find around here. I can probably find
other ones than those I listed, but that might be lesser known
brands. |
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| peranders |
| quote: | Originally posted by Christer
Per-Anders,
I'm pretty sure it is an oxide problem. Using the switches
improved things almost immediately. |
If the switches has silver plating a oxid solver may help. But my exerience with worn out gold plate contacts is not good, espcially with relays. |
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| Christer |
I don't think the contacts are worn-out, though, at least I hope
so. There were no problems when it was last in use, so it most
likely a problem due to a long period not being used, which
makes oxide a prime suspect, I think. Anyway, I'll have to open
it and check it up. It is probably in need of some calibration too,
but that is hardly something I'd dare try. |
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| mrfeedback |
Caig Deoxit has an ingredient that dissolves oxides and leaves a lubricating and protectant oil.
Nothing else comes close in my experience.
Do some hunting and you'll find it.
Ask guys into studio audio or radio broadcast.
Eric. |
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| Christer |
Thanks all for your help and comments. I opened the scope
yesterday and while some of the switches were easy to access
those causing the most trouble were not, and would be a bit
difficult to access properly with sprays. However, it seems that
it was sufficient to do some heavy exercising of the switches.
The problems seem to be gone now so my old workhorse is
once again healthy and ready for action.
It was nice to have a look inside it. Good old late 70's japanese
build. They don't do things like that nowadays, at least not in
reasonable price classes. |
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| mrfeedback |
Christer,
I modify the thin plastic spray tube that comes with the can by removing the metal tubular needle from a syringe and inserting it into the end of the plastic spray tube (I use a large gauge needle, and give it a 45* bend about 6mm from the end).
This tip will insert into small holes typically found in switches and pots, and enables you to reliably flood spray inside and into the parts that need it.
Some pots and switches are completely sealed, so in this case I closely inspect it, and then carefully drill 1 or 2, 0.5 mm holes so that I can get contact spray inside.
I find washed (solvent) and then treated controls work much better than old untreated ones, and will last longer.
Old contacts that are used and rocked back into life give trouble long term, so it is best to give them the proper treatment now.
Even just slightly bad connector, switch and pot contacts in the audio chain give a really rotten low level distortion, that is much better without.
Eric. |
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| Christer |
Eric,
I think I'd better leave my scope as it is, right now, when the
problems seem gone without chemicals. I will remeber your
trick with the syringe for the future, however. It sounds like
a clever idea. |
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| mrfeedback |
Christer,
Thanks for the compliment.
I find universally with audio gear that seems to sound ok, immediately improves and stays improved with contacts treatment.
It can be quite quite surprising the subtle sonic damage that slightly noisey contacts can cause.
Eric. |
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| peranders |
| quote: | Originally posted by Christer
It was nice to have a look inside it. Good old late 70's japanese
build. They don't do things like that nowadays, at least not in
reasonable price classes. |
No, but they are more and more digital, even the cheap ones. |
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