How do i track down a component that is thermal sensitive?
it makes noises and oscillations how do i track this component down
because its related to heat or cold

how do i do some basic thermal troubleshooting components down?

 

What are signs of components having thermal problems?

 

Are you designing the circuit? Seems yes. Then you shall have the required information from the datasheet.

Then you can change the temp of some componets and see the effect... Never tried it myself... :|

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Bharath Bhushan Lohray.
M.Sc. Electronics.

 

If you think the component is showing it's fault when hot, use a hair dryer with a home-made nozel to heat it up. If you think the component only shows a fault when it's cold, use a can of "freeze it" to cool the component.

Brian

 

1.) fault when hot, use a hair dryer with a home-made nozel to heat it up.

2.) If you think the component only shows a fault when it's cold, use a can of "freeze it" to cool the component.

What other Basic thermal troubleshooting skills should i know to track down a component thats like this?

 

If you're getting noise and oscillation when the circuit becomes warm, then the "bad" part could very well be working perfectly. A lot of parts change drastically with different temperatures--this is why electronics simulators let you give a temp. for every part.

The best solution is to design your circuit so that it will work no matter where in the specified range each part value falls. Perhaps do a lookup on "monte carlo analysis".

With the thing already built, I'd wait until it's hot and having problems, then use a can of that freeze stuff on each part. When the right one is cooled, the problem should go away. Unless the part really is defective, however, replacing it will not fix anything.

 

I don't know where these guys are buying their hair driers from, but the store manager probably appreciates their business. I've never seen a hair dryer yet that doesn't depend upon unimpeded air flow to keep the heating element at a safe temperature. Impede that flow and you'll either melt the housing, trip the internal self-resetting thermal cutout or blow the "emergency" thermal cutout that must be replaced at a cost higher than the dryer's worth.

An Unger heat gun, although expensive, is designed for this kind of abuse, although prolonged use with some of its more restrictive air stream attachments can melt the end of the gun as the tip heats up.

If a hair dryer is all you have for heating, then don't impede the air flow. Instead, heat up an area until the problem appears (or disappears) and then use a more selective freeze spray to cool small areas.

And good luck. Thermal problems are some of the most difficult intermittents to find.

Dean

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Dean Huster, Electronics Curmudgeon
Contributing Editor emeritus, "Q & A", of the former "Poptronics" magazine (formerly "Popular Electronics" and "Electronics Now" magazines).

R.I.P.

 

Well some hair-dryers come with attachments as standard which allow you to direct air flow don't they. Personally I did a DIY job and made one of my own. I appreciate that as soon as you impede air flow it's going to put a massive amount of stress on the device, but I don't really care about this. I don't use the hair-dryer for drying my hair, it's specifically for trouble-shooting thermal problems. It's a cheap one and, if I ruin it - oh well I'll get a new one. The advantage of hair dryers is they're cheap and easy to find.

I agree with your suggestion that you can heat the general area until the problem shows up and then use freezer spray to further eliminate surrounding components.

Brian

 

Yea noises that come from old resistors that are thermal intermittent
is really hard because they make white noise and hiss from thermal
heat have to change like every resistor one by one to track it down

 

Freeze-It is awesome stuff. BTW, any can of "duster" works too if you turn it upside down. It'll pickup liquid instead of gas then.

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I thought what I'd do was I'd pretend I was one of those deaf-mutes.