Jooman07

I was wondering if someone would be able to post a picture of the circuit board inside of their RKE key fob. I dropped mine the other day and it stopped working. I looked at it and it is missing a surface mount component next to the power pad on the one side. I can tell it broke off because the pads where the component used to be still have solder on them and you can tell something broke off of it. I'm trying to see what component went there so I can replace it. I can get parts where I work, (Electrical Engineer). I can't seem to find a schematic for it either along with a picture of the correct side. It has to either be a resistor or a capacitor that's missing. More likely a capacitor since it is close to the power input. I know some of you were or are currently Jeep techs so maybe someone has this bit of info laying around somewhere. Thanks!

Ralph77

Best I can do picture wise. From an '00 XJ. Has numbers on it.

315
349 With a line between the 2 like a fraction. Numbers are read right when you have the hook that attaches to your key ring at the top.

Jooman07

Is there any way you can see if there are numbers on the part that I circled on your picture? That's the part that is missing. I think the numbers you see are on the white chip that is below it? The very small black part is a resistor. That's what I need. The number on the part gives the resistance value.

Ralph77

I am sorry. I was all confused and looking at the wrong thing. Forget the fraction number. Eyesight leaves a lot to be desired but looks like 472. Again sorry.

Jooman07

That one looks a little different than mine as well. There are a couple of different parts beside the micro that mine doesn't have. Mine is a 2000 as well but the RKE is one from a 99. I thought that the 97-01 RKEs would be the same since they interchange. It's always worked until I dropped it and it came apart and that part broke off.

Jooman07

No worries. That would be a 4.7k ohm resistor.

A buddy has a WJ and I looked at his and it was a 470 ohm (471 marking) and when I tried it it didn't work still. I will try a 4.7K ohm and try it again. Thanks!

moparado

The 3-digit code for a 471 SM resistor should be 470 Ohms.

For industry standard 3 digit codes:
The third digit is a times 10 multiplier.
For example if it was:
472, that would be 47 X 10 X 10 = 4700 Ohms = 4.7K Ohms
473, that would be 47 X 10 X 10 X 10 = 47000 Ohms = 47K Ohms

There are also a couple different codes depending on the resistor mfg'er.
And some resistor mfg'ers use their own custom codes.

If in doubt, best to measure the resistor out of the circuit with an accurate digital Ohmmeter.

Jooman07

The one that was on my friends WJ remote was a 470 ohm. The one on the 2000 XJ remote is a 4.7k ohm according to them. I've tried both and neither work still so I'm still seeing if there was anything different between the 1999 and 2000 fobs since the one I'm using is a 1999.

I deal with surface mount components everyday, (electrical engineer). If I could find a schematic somewhere of the fob circuit board itself it would make troubleshooting it a lot easier.

moparado

AHH OK!
Same here but retired early.
I hated repairing SM boards. Big jittery hands and too much coffee! LOL
Yeah then you're right a schematic would be ideal or an identical fob.

Only other thing i can think of short of a schematic, did you try using a magnifying glass or scope to see if a hair line crack developed at one of the traces where the resistor fell off?

Jooman07

I did some continuity tests of the traces but they all seem to be fine. If I can't repair this one I'll just end up finding one from a part out maybe and replacing it all together.

moparado

I haven't used my remote fobs for years now but still have them around somewhere.
See if i can find them and post tomorrow.
Hopefully its the same as yours.

moparado

Jooman07, if you're still out there, my remote appears to be similar to yours. Sorry about the blurry pic.
The missing resistor is a 471 on my remote.
Maybe another component popped off?
If you need a clearer pic let me know, ill try to find my Nikon.

Jooman07

Thanks.

The first one I tried was a 470 ohm resistor and it still didn't work. I think at this point there's something else going on with it and I may need to just replace the setup all together.

moparado

Other than another component that popped off, maybe the crystal got trashed from the drop impact.

The reason i don't use mine is because it works once in a great while when it wants to. Even with new batteries, cleaning the contacts, etc. but its still intermittent as hell.
Good Luck.