Help Please : GE Monogram ZISS420DRISS freezer stuck at 54 degrees

[Andyx222]

Model Number

ZISS420DRISS

Brand

GE

Age

More than 10 years

Hello All,

First time poster here. I have a GE Monogram ZISS420DRISS manufactured in 2006.

One day I noticed everything in the freezer melted. I set the freezer to 0 and FF to 40 but current temperature readings on the display are 54/54. Occasionally, it seems like the conpressor turns on but only for a few minutes. Air coming into the freezer doesn’t feel cold enough.

Things I’ve tried already:
- Entered into Diagnostics mode to test thermistors (all are ok according to the display)

- Entered Diagnostics mode to reset the system

- Cleaned out all the dust built up on the back of the condenser.

- Unplugged the unit for 15+ minutes and then back on. Temperature still stuck on 54 and 54

- Condenser pump doesn’t feel warm to the touch, turns on but only for a few minutes.

- I have pending sales for a new motherboard and a new inverter board, hoping that’s it.

Any ideas or direction? Your advice is appreciated! Thank you in advance!

 

[Jake]

Hi,

Did you go by all the testing from this thread: FIXED Monogram ZISS420 will not cool

Here's the main motherboard for your model:
Main Control Board WR55X10560

The inverter receives commands from the main control board. The main control board will send a PWM run signal from the J15 connector of between 4-6 VDC effective voltage to the inverter (all wires must be connected). The inverter will select compressor speed (voltage output) based on this signal.

The main control board will only send a run signal to the inverter when the compressor should be on.

Note: When measuring signal voltage (from the main control board) at the inverter, a reading of 4-6 VDC will be measured with all wires connected.
The inverter will monitor compressor operation and if the compressor fails to start or excessive current draw (4 amps maximum) is detected, the inverter will briefly stop voltage output. The inverter will then make 12 consecutive compressor start attempts (once every 12 seconds). After 12 attempts, if the compressor has not started, an 8-minute count will initiate. After the 8-minute count, the inverter will attempt to start the compressor again. If the compressor starts, normal operation will resume. If the compressor fails to start, this process will be repeated. Removing power to the unit will reset the inverter count. When power is restored, the inverter will attempt to start the compressor within 8 seconds.

Here's the inverter board for your model:
WR49X10283 Inverter W/jumpers Kit