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Electrical Wiring in the Home/Petsafe RF-125 transmitter w/ blown resistor


hat trick wrote at 2012-07-15 19:13:18
Hi.  I was hoping you could help me as well.   I too had a lighting strike.  My RF125 failed the short loop test.  I replaced the unit through Petsafe.  The new unit keeps blowing fuses.  I cleaned up a repair to the fence that I know sometimes gave the old unit trouble.  The unit now stops blowing fuses, but after I plug in my boundary wires, it begins to smoke, sizzle and the little cylinder inside (markings of 25v, 2200 mf) is bubbling.  The unit is not grounded.  any suggestions?

djc wrote at 2012-07-27 02:42:50
Exactly the same issue. Exactly the same resistor. It's a 2.7 ohms...

Side note: the value of the resistor influences the fence boundary width. A lower resistance will increase the boundary width.

Mark wrote at 2013-05-16 01:54:08
I've seen this question multiple times on various forums as I look for the answer to this question as I encountered the same issue today.   If I jump the resister entirely, the system appears to work fine.    I was lucky enough to find that the paint on the lower side of my resister is still visible.

The ring colors for the resister in the R29 slot are red, green, gold, gold.   

As best I can tell, that is a 2.5 Ohm 5% resister.  

Mark2 wrote at 2013-05-30 22:00:15
Mark, thanks for your input!  I've been looking all over for the specifications of the R29 resistor.  I've finally found it.  Although this is not the CAPACITOR (C1) that the original question was referring to, this is exactly what I need and hopefully this will help anyone else who needs to repair their Petsafe RF-125 Pet Fence Transmitter.  I found this link - - that shows a picture of the circuit board with the R29 resistor blown.  Now with your info of the R29 resistor and this picture, anyone should be able to identify the proper replacement part, should it be illegible/destroyed.

Anthony wrote at 2013-09-13 13:16:55
i Have a working unit so I measured the resistor and it is a 2.4 ohm resistor.  I think it is a 1/2W or 1/4W

Makary wrote at 2014-04-21 13:53:06
For Haven sake, WHAT is the resistor? Ohms and wattage?

This resistor blows all the time - mine just fried - what resistor do I need to replace it with?

HARPER wrote at 2014-05-19 23:42:26
Well I must be the 2nd in a million because i replaced the same resistor #29 with a 30 cent replacement and the fence is working again. sounds to me like someone at petsafe doesnt want you to know this so you have to buy a new $120 unit!

Bill wrote at 2016-05-02 21:54:00
The resistor in question is red yellow gold gold which is 2.4 not 2.5. I'm still confused about the two gold bands, but since people have tested it and it comes out 2.4 ohms I'm going with that.

Chet Seibert wrote at 2016-09-09 17:16:52
I've verified from 1 of 3 of my blown transmitters that it is a red yellow gold gold resistor. That translates into 2.4 ohm 5%. The third gold band is the multiplier(in this case 0.1). That makes it 2.4 ohm. The size is approx. 9.2 mm which makes it a 1/2 watt type.

Chet wrote at 2016-09-12 21:22:49
Just soldered in one of these 4 band resistors(red yellow gold gold - 2.4 ohm, 5%, 1/2 watt) and the transmitter is working normally.

Joe wrote at 2016-09-14 13:48:18
I do not have a resistor on my RF1010. The C1 capaitor is blown. Anyone know the value of this capasitor?

Chet Seibert wrote at 2016-09-15 15:06:13
Joe, I also have a RF 1010 blown transmitter. The capacitor in the C1 position appears to be fine. The resistor next to it(R29 position on my RF 125) is blown out. This is the same resistor as my RF 125 and in the same position. The R29 label is under the resistor so it has to be removed to see it. The RF 1010, I noticed, has a couple more differences compared to the RF 125. The RF 1010 has an internal, soldered in line fuse(F1 label. The RF 125 has a replaceable 1A/250V fuse accessable from the  back of the unit through a little door. The internal line fuse on my RF 1010 is also blown and I will need to get a solder in type to replace it along with my blown resistor. The RF 1010 also has no ground position for a grounding wire.

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Electrical Wiring in the Home

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Kevin L. Ogle


I can answer any question regarding the wiring of invisible dog fencing. I am especially skilled in the installation, repair, dog training, and maintenance regarding the system. I am not qualified to answer any questions regarding AC house wiring or installation.


I have been installing and troubleshooting invisible dog fences for the better part of 15 years. I have an Associates degree in electronic engineering, and know the system both inside and out. I personally use the fence and training products & can answer most questions regarding pet training with electronic stimulation.

AAS in Electronic Engineering, The Logistics Institute (Georgia Tech)

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