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EX120-2 burnt Resistor PVC

auy_tong2 ยท 2011-02-10 02:51

what causes this? on the PVC

Replies20
  1. #1KenAl2011-02-10 07:21

    What I have seen is the Pump Angle sensor gets hot and shorts internally. This causes the 1 amp PVC fuse to pop. Then someone runs out of 1 amp fuses and puts in a bigger one. The resistor then burns. I have also seen where any of the sensors or wiring for the sensors have a short to ground, this will burn the resistor.

  2. #2rgl7262011-02-10 07:38

    i can provide you a brand new pvc.

  3. #3fast_st2011-02-10 10:15

    That looks pretty ugly! would check the transistor at the upper left for damage as well, if you overload a transistor sometimes they melt wide open and start cranking current through them. Likely at least replace the diode and resistor and that amplifier/switcher.

  4. #4spitzair2011-02-10 13:56

    My EX200-2 had all kinds of shorts in the wiring harness under the engine on it's way to the pumps... Caused the same problem, except it didn't look quite as bad... I fixed all the wires that I could find broken (took me almost 10 days), tested all the sensors for correct resistance and replaced the resistor but the computer still didn't work, pops the fuse immediately. I bit the bullet and bought a new computer, but haven't been home since it arrived to put it in and test it... Hope you can find a used one for a good price somewhere, they're pretty spendy little items...

  5. #5KenAl2011-02-10 19:00

    I would try to change the resistor. I would not plug it in though until you find out why it blew. I have done this many times in the field and have been lucky with just changing the resistor although some have had additional problems. I used to carry one with me. I cannot remember the wattage or resistance. The wiring harness for these types of machines are the life blood of the machine and must be in good condition.

  6. #6auy_tong22011-02-11 01:53

    wattage and resistance of the resistor please...

  7. #7fast_st2011-02-11 12:23

    KenAl might have it, I can't seem to find a resistor with four smoke colored rings and a black tolerance band. Guessing says it looks like a 2 watt maybe 1k resistor. The computer might be good but getting the right parts. Having a good working unit to compare to would be great. Might be cheap to replace the unit.

  8. #8JeremiahSr2011-02-11 14:31

    I think that is for the swing brake circuit? Maybe bad solenoid or wires?

  9. #9spitzair2011-02-11 15:36

    If I remember right it's a 10 ohm 4 Watt resistor... Hope that helps.

  10. #10auy_tong22011-02-11 22:44

    your right its a 10ohms 4watt:notworthy

  11. #11auy_tong22011-02-11 22:50

    what pins to bench test the pvc if it will power up??

  12. #12auy_tong22011-02-12 03:36

    we don't have 4watts here only 5 watts..

  13. #13Ingvar2014-07-03 01:47

    Hello I have the same resistor (R1) looking burnt on my circuit board. Also, the Zener Diode slightly above it, ZD1, is damaged from heat. It may only be exteriorly damaged, but I wish to replace it. My resistor actually still measures 10 ohm, and the zener is measuring 0.5 volts one way, and I can't measure the zener voltage. Did you have any luck changing your resistor out? Does anyone know what the zener diode is? Voltage and amps? ZD1 and ZD2 seem to have different numbers written on them. ZD1 is partially fried on my board, though. Thanks

  14. #14dbs703012015-10-20 20:24

    I have a ex120-2 with the same problem .I've replaced the pvc and is not blowing the 1 amp fuse any longer, its now burning the resistor instead . Im in the process of looking for wiring problems . I cannot find a 10 ohm 4 watt resistor . Anyone have a picture the resistor or a place to buy ? Thanks in advance .

  15. #15jaytech2015-10-20 21:23

    its ok to use a higher wattage resistor as long as you have room to install it. also its normal for a 4watt resistor to generate heat you should double check your fuse to insure it is 1 amp if its a small resistor with colored bands painted on it I would suspect it is a 1/4 watt not a 4 watt how about a picture of your board?

  16. #16rgl7262015-10-20 23:31

    if the resistor is always burning your angle sensor is the problem. replace the angle sensor.

  17. #17dbs703012015-10-21 20:14

    I dont have the box on hand to take a picture of it but the resister is about 1/4" in diameter and 3/4" long .

  18. #18jaytech2015-10-21 23:03

    yeah I guess that sounds more like a 4 watt ceramic

  19. #19danaocity2015-10-22 08:46

    Auy_tong2 If u don't mind can I have your email address. I'm also in CDO. Heres my email add just in case [email protected] Thanks

  20. #20dbs703012015-10-22 13:57

    Dont want to hijack anyone's thread so Ive started another with pics. HeavyEquipmentForums