Not cars, any electronics advisors here?

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Gibbo2286
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Not cars, any electronics advisors here?

Post by Gibbo2286 »

I've got an HP A3 printer, it failed to start, pressing the start button just flashed the green light, I stripped it down and checked out the circuit board and found that the yellow gummy stuff that supports the various electronic components had become, with age, conductive.
I've carefully removed it with a craft knife and the thing's back in business but I don't want to leave the components unsupported so the question is what the hell is that gummy stuff called and where can I get some?

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Paul-R
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Re: Not cars, any electronics advisors here?

Post by Paul-R »

I don't know what the original stuff is but when I've had to stick components in place I've use a hot melt glue gun. Although I haven't specifically been trying to avoid the electrically conductive soldering areas I haven't tested the conductivity.

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Re: Not cars, any electronics advisors here?

Post by Gibbo2286 »

I Googled it Paul and found myself in the midst of a heated debate by some 'experts' , heated glue stick, quick cure silicone rubber, epoxy resins, etc. but no name for the stuff.

The original looks a bit like epoxy but I don't want to use that and find myself back to square one.

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Re: Not cars, any electronics advisors here?

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Paul-R
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Re: Not cars, any electronics advisors here?

Post by Paul-R »

More likely to be a conformal coating as mentioned in the Wikipedia page. Not a term I had ever heard of previously TBH.

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Re: Not cars, any electronics advisors here?

Post by Gibbo2286 »

Following James's link it seems polyurethane is likely the best and guess what, a pot of Evo-Stik wood glue on my shelf has the right formula so I'll give that a go.

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Re: Not cars, any electronics advisors here?

Post by GiveMeABreak »

Moved from the Citroen Section to the only other 'General' area we have.

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CitroJim
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Re: Not cars, any electronics advisors here?

Post by CitroJim »

Having worked extensively on HP laser printers in the past I know exactly the stuff you mean but have never encountered any problems with it...

I have two old HP lasers here in regular use... I must now check and both are 10 years old and then some now, especially my colour laser. It is so old it has a setting for printing cuneiform tablets!

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Re: Not cars, any electronics advisors here?

Post by Gibbo2286 »

This one's an ink jet a 1220C Professional Jim, the consensus on the HP forums is that this type of failure is common and that it's usually caused by a blown R13 resistor , that wasn't the case with mine but I found by pure chance that it was power leaking away though this paste, cleaning it off fixed it.

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myglaren
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Re: Not cars, any electronics advisors here?

Post by myglaren »

Factory I worked at, we would clag everything on the prototypes down with superglue or hot melt, sometimes both.

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CitroJim
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Re: Not cars, any electronics advisors here?

Post by CitroJim »

Ahh, I know those 1220Cs very well.. Good printers too..

I'd not worry unduly about supporting the components in a domestic environment. Just check they are in no danger of shorting to adjacent components or metalwork under gentle movement, especially whilst actively printing, and you’ll be OK I'm sure...

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demag
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Re: Not cars, any electronics advisors here?

Post by demag »

I remember using candle fat on pcb's we made up.

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Re: Not cars, any electronics advisors here?

Post by Paulmi16 »

Some Anti Corona Lacquer might be beneficial to prevent any further surface tracking or current leakage.

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Re: Not cars, any electronics advisors here?

Post by dnsey »

Yes, that yellow glue stuff is well known for becoming conductive in all sorts of equipment.
I'm with Jim - in a printer's typical environment, there's no real need for it. I suspect it was used primarily for transit protection (or to try to compensate for dry joints, perhaps :( ).

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CitroJim
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Re: Not cars, any electronics advisors here?

Post by CitroJim »

demag wrote:I remember using candle fat on pcb's we made up.
And for locking cores on IF transformers in radios and TVs...

Happy memories of melting a candle with a cigarette lighter flame and hoping the molten wax went into the right place!

And praying you didn't accidentally burn yourself in the process :twisted: