Owon TDS8204/PeakTech 1300 repair

[ra-ma]

Hello, I got a PeakTech 1300 aka Owon TDS8204 oscilloscope from my father in law. Issue description is "stuck in boot screen".

To check if it's potentially the power supply, I connected the main board directly to my lab power supply, skipping the internal power supply: The board takes 3 amps at 5 volts. It starts, shows the PeakTech logo but nothing more. So exactly same behavious as with the internal power supply.

In the input area of channel 2 I found a burnt 50 Ohms resistor (see picture) which I already swapped with a new one, but no change.

I was checking around that area for issues, but can't find anything:
- NEC relays are fine as far I can tell (measuring resistance between pins 1 and 8, unsoldering the one close to the burnt resistor, applying 4.5 volts, it's closing/opening).
- The battery (MS621FE) only has 2.5 Volts. I added another one in addition with 3.1 volts but no difference.

Any ideas where to look? Could it be more a soft- or hardware issue? Unfortunaltely I can't find helpful material online, doesn't seem to be a well selling oscilloscope...

I don't know the boot sequence of the Owon. My Rigol does some relais clicking at the end of the boot sequence, the Owon does a click (sound like several relais are switching) at the moment it gets power. Afterwards nothing happens anymore...

Looking forward for any tips and ideas.

[m k]

Maybe battery voltage was too low, settings disappeared and the machine doesn't know how to boot.