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ANYBODY ? slow starts. Used to be instant. When warm now uses more current?

dolftb

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Its very diffucult for me to run like that. I have been able to but its all pretty micjey mouse. However, I had heated the probe and cooled it , startup delay remains. Put it in the frigde. with the diode cold and the senser not cold , same start up delay. I am thinking about disconecting the probe to mesaure resistance of the probe. But I really dont want to go there actually.
 





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Hmm. Do you have a digital multimeter capable of measuring high currents (1+A)? If so, try desoldering one of the leads from the driver to the diode and putting your DMM, in series between the disconnected lead and the driver (in current mode of course) and try measuring current output that way and observe.
 

dolftb

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From my earlier post

I took the driver out and messured 1.3 amps to the diode will pulling 2.7 out of the batteries. this is after about 30-45 secs.

The current to the diode starts at 0 amps when turned on and then ramps up to the 1.3 amps so this does take around 30 secs in total."

Is this what you were referring to ?

Thanks again....
 
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Oh. Yeah. Hmm... very interesting. So the temperature probe does not change that, the batteries don't change that. Intriguing.

I think the only possibility left is that the driver is defective at this point, or took some damage some how (or just something lost contact, whatever). Can you check for continuity with a DMM where it should be continuous?
 

dolftb

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"Can you check for continuity with a DMM where it should be continuous?" I dont understand exactly what you mean. Sorry.
 
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What I meant is use your DMM probes to check the resistance between various points on the driver to determine if everything is connected properly, i.e. the two pins on a chip that are supposed to be connected should have 0 resistance, but if they have 2 ohms of resistance, then there is a connection problem.
 

dolftb

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Oh okay. I will try that. I also tried to measure the resistance of the probe although its connected to the board, however the resistance does change from 980ohm to 915ohm between ambient temp and higher temps created with blow dryer. So it seems that the probe word not be defective then.
 
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Are you sure that the probe isn't supposed to go any lower than 915 or any higher than 980? The probe itself may be damaged and just partially functional now.
 

dolftb

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Well that is possible I know know what the probe reading s should be and still soldered to the board is not really the right way to measure. The only thing is that it seems to be doing something. If I were to get no flucation then I would assume the prob to be completly dead. Could you look and the pic of the board for me ? There is a resistor I am measuring .59 ohms on both side of the resistor with 1 DMM pen to ground. Seems odd ? I would think to have different measurements on both sides of the resistor. Can you tell the resitance btw ? I cant read the ring codes on those darn things.
 
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May I suggest that you measure the resistance between the resistor instead of one lead at GND? Like put the black lead on one end and the red lead on the other?

And if you could tell me what the colors on the band are I could answer for ya - I just can't tell the colors that well on that thing.
 

dolftb

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Okay will do, in the mean time. I am starting to doubt if the probe is not giving flase readings like you suggested ealier. im trying to find out what the ohm range should be but have no clue were to find that info.
 

dolftb

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So I ended up disconnecting the probe which makes no difference. Now sometime when switching on it may take longer and/or flicker slightly and erraticly. Once its goin its fine. Wonder about a fauiling MOSFET ???
 




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