25cu french door Lg LFC25770SW, no water dispenser, ice maker never hooked up. bought new about 8 years ago, kept clean.

noticed fridge not as cold as normal a week ago, but ice still solid until yesterday, now ice melting and fridge pushing 50f.

no error codes on temp display, but test mode (from main board) doesn't seem to do what I would expect and it doesn't seem to want to go into mode '3', jumps from mode '2' back to normal operation.

compressor operates for short periods of time, but feels rather hot. lines in and out of compressor at room temp. cond fan running. I feel air flow inside so I assume evap fan runs as well (only with doors closed).

how does one check the state of the r134a in case of leaks? I own automotive gauges but can't find a hook up.

it acts as if defrost timer had failed, but I can't find any info to suggest this even has one.

no ice forming anywhere inside or out. coils clean. doors seal.

volt meter handy, spare parts store close by.
mother in law comes for a visit inside of a week, so......

please help.

small update: I did notice that the compressor will run for about 20 seconds every 10 minutes or so. not sure if this is meaningful info or not.