Bought a PIC18 based LC meter some time ago,
it has a Nokia5110 display which so far, works.

Power supply is 9v jack, I soldered a 9v battery with wires.
There is a 78l05 and also AMS1117 3.3

The LCD menu works 100%, however, neither caps nor inductors can be measured at all.

Sometimes erroneous values show, sometimes it stays at zero.

I tried around a lot, but to no avail.

Is it broken maybe, or a wrongly soldered component?

 

What is the oscillator? Normally they have an external opamp or comparator oscillator?

Photos and a schematic would be a massive help here!

 

I guess the internal comperator from the PIC18 is used.

There is no schematic included, but yes, I can post a photo shortly.

Checked solder joints of course but did not find any faults.
my guess is a swapped resistor perhaps.

Why didn't they check it before shipping? I sent ebay message but no reply, typically with these chinese reseller megastores.