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Usi 3155b


TKK
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Got this combo and its making a ticking noise like it tries to start the compressor and doesnt. My hvac guy connected it directly and it worked. Something smells burnt by the front pannel where the relays are, he said everything seems good but the transformer is a bit warm. What could it be?

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If the compressor doesn't start when it tries to then the start relay is probably bad.  You can't plug those units direct to the wall because they don't have that kind of plug on them, they are wired into the machine.  The USI compressors are from Danfoss who uses cheap, crappy starting components.  Change them out for a hard start kit and that will solve the clicking-without-starting issue.  The transformer will always be warm because it's converting 110v to 24v which generates heat.  Why do you need the CB500 board?  I can send you a motor for the CB500 but why do you need the fan blade?  Email me a pic of the fan motor to ensure I know which one you have.

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Hey randy, so...

 

On the combo the hvac guy connected the compressor plug directly into a power source and it ran. Then when we put test relay 1 it runs for like 10 seconds. Then we changed it from snack to combo (maybe the machine changed to it after so many failed attempts) it cycles on then off then starts ticking. It gave the error code  67185-08 which said please call for service. 

 

For the cb500 the radiator was freesing up, the hvac guy took off the fan and it wasnt working. He then took off the blade and ran it manually and it would spin. However he put the fin back on and the screw kinda messed up or the threading on it so apperantly its lose and he couldnt tighten it well. So it runs but makes a loud golpher sound.

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This is what happens when you use a non-vending tech.  The Relay Test 1 is only to run the unit for a few seconds - it's a test and may not turn any fans on.  The "error code" you saw is just the eprom version number that shows when the logic board initializes, like when you first turn the machine on.  Call for Service may mean you have some part of the programming wrong and it's conflicting with itself.  I wouldn't pronounce it a bad board yet unless you can't get into the programming now.  See if you can do that and then follow the manual's programming instructions for setting the machine default back to the factory setting that's dictated by the eprom before you do anything else.  This is probably a SM6 logic board if it has a blue display.  Here's the manual for it: https://www.vendnetusa.com/wfdata/files/4211417e.pdf

On the CB500, your AC guy probably cross threaded the plastic nut that the fan screw goes into if the fan blade is loose, and it should not have been reinstalled in that condition.  I hope he doesn't fix air conditioners like this, but he is out of his area of expertise.  Regardless, it sounds like you need a new evaporator motor.  You have to be really careful with reinstalling that fan motor because there are about 12 screws that hold the evaporator housing in place and they are a golpher to put back in.  That might be part of the noise you hear.  If the housing isn't straight the fan blade can hit it or the cabinet bottom because that heavy fan is mounted to the housing in another brilliant design move by USI.  There are also certain screws that go into certain parts of the fan motor (it should be a square motor) and if you put one long screw in the wrong hole you will short out the motor winding and blow the motor.  Email me if you need one.

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Whats ur email randy? I do need one. I guess ill try to reprogram the machine. However i left it on and noticed it stays cold the combo, but does have problems starting, u hear a ticking like a starter is trying to start it but is to weak, then i guess it gets enough juice to run it a while

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If the compressor does eventually start then the start winding is getting weak in the compressor dome.  The only thing you can do to get more life from it is to put the hard start kit on it.  Once it stops starting and running all together is when you have to replace the compressor.  email me at rbepic4gatgmaildotcom

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