You seem to be in all threads. Thanks for your help
There is an on/off switch in the case, try that to rule out the front panel/flex cable. Often, the failure will be obvious on the power supply board, on occasion the large caps off the mains will fail, or one of the large clamping devices in the same area. Look for leaking electrolytic on the board. Same power supply as the TDS520/540/520A/540A/544A and 620/640/620A/640A/644A.
Replace ALL smd electrolytics prior to powering it on…
Yes, the ON/OFF switch is OK. And when you connect the plug, there is the usual spark noise so the primary side seems OK.
I have removed the PS cover and there is nothing evidently damaged. In fact, the unit looks very clean
, with just some slight dust.
About replacing all SMDs, I know it is a must once I get the PS doing something but, is it so important to do that BEFORE even getting the PS to work?. I mean, may be that the problem for non-start?. Visually the SMD caps look OK (well, I have had no time to check in great detail yet, but there was no obvious damage as I have seen in other Tek units, as the 2465B or 2430A). I will replace them, for sure, but I guess fixing the PS has higher priority. Am I completely wrong?
So, one question... are there some test points on the PS I could use?. I guess there is no detailed info / schematics of the PS, right?