Frigidaire FFHB2750TS9 Compressor Not Running

[Howard Duncel]

My daughter's Frigidaire FFHB2750TS9 stopped cooling yesterday.  I discovered the Condenser Fan had come off the fan motor, so I put it back on.  After reassembly the fan motor was turning, but the condenser coils were not warm and the compressor wasn't running.  Checking the windings on the compressor yielded ~18 Ohms across all pins.  The inverter module is receiving 120VAC, but the plastic housing had yellowed and was brittle and cracked when pulled away from the compressor.  My thoughts are the fan wasn't cooling and the excess heat simply caused the Inverter to fail.

Ian anyone advise of additional troubleshooting needed, common causes, etc?  Thanks in advance!

Howard

[ServiceTech_Daniel]

this inverter has two inputs . it has its own 120 power supply as you already checked that. and a DC control signal input from the main control board 12vdc 

if you have 12vdc at the control signal input and the compressor isnt coming on, you have a bad inverter . If you dont have 12vdc. You need to go to the board and see if its outputting the dc voltage from connector J4 pin 11 and 12 . if you have no dc output from the board then you have a main control board failure

 

Edited December 28, 2023 by ServiceTech_Daniel

[Howard Duncel]

Thanks Daniel.  The schematic I have shows the control signal as PWM.  Since I couldn't locate any documentation to indicate what the DC value should be, the info on the 12Vdc control signal is appreciated.  I'll check that next. 

[ServiceTech_Daniel]

18 hours ago, Howard Duncel said:

Since I couldn't locate any documentation to indicate what the DC value should be, the info on the 12Vdc control signal is appreciated.  I'll check that next. 

No problem , keep us updated on your progress !

 

[Howard Duncel]

The Inverter module was defective.   After replacing the module and confirming operation had returned to normal, I opened the original module and found capacitor C102 (390uF @ 200Vdc) to have gone bad ... puffed up from heat.

Thanks again for your help, it is appreciated.

 

[ServiceTech_Daniel]

Awesome to hear, glad you were able to get it fixed! 

Daniel