[hamid_1]

For future reference, it might be worth looking out for the Mk.1 version of the KV-1320UB (serial number below 100,000). This has a linear power supply using a heavy mains transformer which also isolates the rest of the set for added safety. The linear power supply is much less likely to suffer catastrophic failure, unlike the Mk.II which in your case seems to have self-destructed.

The Mk.I can still go wrong, though. I have one in which some of the small signal transistors have started to corrode, their pins turning black, eventually causing component failure. Luckily, substitute replacements are available for most of the small signal transistors.