Update for this manner, positive also, as one came alive! It was alive before, but now signal is not distorted at all, and all i did was take cover off and turn it on. Funny thing is, that one resistor was loose inside case, rattlin' around, so would it be wise to locate it's place? or is it necessary as it works well now....
As it's in working condition, should i sell this or my previous, there is only one thing better in my older scope, and that is biggest volts/div setting. Older has 10v/div, and this new one has 5v/div. Also bandwidth is much diferent, older has 10mhz, and new one has 140mhz. Both are 2-channel. older also has adjustable triggering, whereas newer adjusts it via time/div knob. I simply dont have need for this many scopes, i already have 2 extra 4-channel scopes at shelf....
But back to topic, the scope that gives smoke, has something weird in PSU section, heat haze/smell/smoke comes from there, and the picture shows lm317, which gets pretty hot pretty fast, as does transformer, which is alarming sign, i mean that transformer is too hot touch!.
The other scope, which has distorted signal, has fuzzy signal no matter what are knob's settings, see from photos gnd-settings on both channel. it does swing and change amplitude in x-axis when frequency knob is turned, but only one sweep, sometimes not even that, sweep stays at the left corner. Quite hard to take picture..... And i did find one burnt-looking resistor, hopefully you'll see is from pictures. There seems to be other symmetrical portion, where all are same on pcb, but of course resistor isn't burned looking. If i recall right from amplifier troubleshooting, oscillation can kill resistors/transistors, but what do you think about these two(three) faulty scopes now, as there is some info in hand?