I have this scope and first symptom is failed time base selftest , after few time fail synchro on screen. After unasembly all parts R52 on power supply is burned. After replace with similar value because original value is unreadable scope work only first time. Regardless of that can anyone help me at first with some good tip or scheme of this PSU or only with value of R52 and R48(I'm not sure of this value) of this PSU. My next step is replace all electrolytic and axplore the circuit to write scheme. Thanks in advance for any tips and informations.