pcb components for dei brains?
Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=119835
Printed Date: April 25, 2024 at 3:17 AM
Topic: pcb components for dei brains?
Posted By: bruno molly
Subject: pcb components for dei brains?
Date Posted: February 02, 2010 at 1:32 PM
Does DEI sell Circuit board components for there Alarm/keyless entry Brains? I have 3 with smoked resistors on the Trunk Release output. Either 10 ohms or 9.5 ohms is what a good one reads. I am getting no (-) output on the output side (terminal), but I do get an output on the good side of the resistor. [100]is printed on the component, a SMD tiny resistor. Anyone ever encounter this? I can get the part from Digikey if I had the specs. Not sure if they will release that information. Emailed them yesterday but haven't gotten a reply.
Thanks
-=Molly
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The Sky is not the limit....The Ground is!
Replies:
Posted By: Ween
Date Posted: February 02, 2010 at 2:49 PM
what model is the unit? maybe someone here has the same piece that they could peek inside and take a look. post a pic of the board in the area of the burned up part? m
Posted By: KPierson
Date Posted: February 02, 2010 at 3:35 PM
Chances are the actual value of the resistor isn't all that critical (or you wouldn't have three burnt up ones). Kidding aside, I would see if you can trace out the circuit - if it is trunk output it most likely goes from the processor, through the burnt resistor, then to a darlington transistor array. The resistor is probably there to protect the transistor it drives (by limiting the current in you limit the current out). I would guess you would have no luck at all with DEI in getting components, especially since they have lifetime warranties on most of their brains. ------------- Kevin Pierson
Posted By: bruno molly
Date Posted: February 02, 2010 at 4:00 PM
Python model 881XP
The Resistor to the left circled in Green is the part that is Identical to the smoked one that I need. [100].
I measure 9.5 ohms on all of them without removing them.
The Smoked one now measure 200K ohms.
I can get a good reading on the signal presentation side, but no signal thru the smoked resistor.
Anyone have any Fried Brains or cannibalized units
that you may want to get rid of let me know. Or, knowing the
true Value, Size, Material its made of (Thin Film is my guess) Wattage, Case style, we can see its a Surface Mounted Device (SMD) and tolerance (+ - 5% 10% etc)of this resistor would
be helpful to know.
Thanks for your help!
-=Molly ------------- The Sky is not the limit....The Ground is!
Posted By: bruno molly
Date Posted: February 02, 2010 at 4:11 PM
What happened was this... The guy who was testing these out, used a TAPED up DEI Harness, and some Knuckle head had Soldered the RED / White wire (Trunk Release which is a (-) output), To the RED wire next to it, the Constant +12V. So when he activated the Trunk relase with our Test rig, the bulb we used to test the output didn't light up, and we smelled the Inevitable! This is how we got 3 Toasted Brains on this output. Bypassing the Resistor it works like a charm.
The 2nd unit is a Viper 791xv, and the 3rd unit is an Avital 3300.
I Really on need 3 resistors but I always like to have extras.
-=Molly
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The Sky is not the limit....The Ground is!
Posted By: KPierson
Date Posted: February 02, 2010 at 4:59 PM
ok, I was wrong with what I said above, the resistor is on the collector side of the transistor, used to limit current on the output (to roughly 1.41A). What voltage were you testing at? I would get on digikey and order several 10 ohm surface mount resistors and see what fits. You figure 10 ohms at 15vdc will allow 1.5A to flow through it. 1.5 * 15 = 22 watts. Something doesn't sound right there (which is why you have burnt up resistors). It almost seems like they are using the resistors more as fuses then resistors. I believe the output is rated at 200mA. .2 * 15 = 3 watts. That is still high, but much more believable. If you want to try to get more precise mic the resistor and then find the correct footprint in the datasheet. ------------- Kevin Pierson
Posted By: t&t tech
Date Posted: February 02, 2010 at 6:11 PM
That output is rated at 200ma!
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COMMIT YOUR WAY TO JEHOVAH AND HE WILL ACT IN YOUR BEHALF.
PSALMS 37:5
Posted By: jeffwhiteman
Date Posted: February 03, 2010 at 1:56 PM
surface mount resistors are marked with a 3 digit code. (100) the first 2 numbers are the value and the third number is the power of ten (number of zeros) so 100= 10 ohms and 101= 100 ohms.
If you dont want to wait for an order you could remove the burnt resistor , solder some leads to the board, then attach a standard radioshack resistor(tape off the exposed leads and stuff it in the box.)
I do however suspect something caused excessive current to flow through them though, but its worth a try.
Posted By: bruno molly
Date Posted: February 03, 2010 at 8:52 PM
Ok...Thanks for that informative explanation!! I was wondering. Resistors have come a long way from those color bands. I bought some from RS today.
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The Sky is not the limit....The Ground is!
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