I've got an Emerson ( ~ Sangean) ATS803 that has started to mistune.
Example:
Basic commercial FM band tune in 99.1MHz and get intermittent shift in recieved signal as high as 99.9, with no alteration in displayed frequency (reads 99.1).
This gradually worsens (by frequency pull) until the 99.9MHz signal is continuous. To get 99.1MHz signal out then I have to tune displayed frequency to ~ 98.4MHz. This is just a notable example - smaller shifts have been seen (AIR). I've had to retune the display downwards in increments to keep the 99.1MHz reception.
It is physically dependent on something. With the case open, pressure on front display can induce it, though all ribbon cables have a fibre insulator installed to prevent pentration of sharp component leads.
With RF board lifted, there seems no predictable or repeated movement of anything simple that can induce it, but movements of the entire rf board will: This can occur with RF board close or distant. No assembly pressure on cables is required.
Tapping/wiggling cables and connectors doesn't aggravate or repair it. Tapping/rotating the digital tuning assembly doesn't affect the intermitency.
Finger placement/force on RF board doesn't change anything.
It's sitting on the bench open and behaving, but I can induce problem with mech RF board movement or by reassembly at any time.
Ack.
RL