Re: Echostar 680W power good 0V

Finally! One of the C945 transistors was slightly defected, and I could not determine until I pulled out from pcb... Now the computer is waiting till I press Power_on button...
Thanks for help, and sorry for my bad english...

Re: Echostar 680W power good 0V

No, not yet. Power good is now 5V and 390ms, but the computer still starts immediately after connecting 220V power.

Re: Echostar 680W power good 0V

It's almost indentical to this scheme:...

Re: Echostar 680W power good 0V

Re: Echostar 680W power good 0V

All caps replaced, and that's it! Power good 5V and 390ms. Obviously, my esr-meter not working well...

Re: Echostar 680W power good 0V


One more picture... Yes, it is for 220V, why not? 2 caps with 200V in serial connection......

Re: Echostar 680W power good 0V



Voltages:
5.13V
3.37V
12.03V
Pictures:...

Now is it really 680W as it says on the label - I would not say, rather, it is somewhere around 400-450W ... The company is "Echostar", nice "golden" cover even the quite heavy, with two fans. The interior is very simple - on the secondary side of a single LL(TL)494 and 10 TO-92 transistors plus TL431... Anyway, what happens: after applying voltage to 220V power, the computer starts up immediately, and works normally. Power supply tester shows 590ms PG and it blinks and beeps... Power good signal is 0V... Suspicious electrolytes are replaced, and replaced TL494 too... I have...

One day monitor dies. No led, no nothing. Resoldering, replacing capacitors, measuring semiconductors, no result. One big fuse ok. But, one picofuse opened in Vcc line of TL1451A. Replacing picofuse. Monitor woke up, but only white screen. LED functioning is back. Why only white screen?