Dragged this out of the dumpster at the BB next door (thanks Geek Squad guy!). At first I thought it was going to be OK - appeared to try and power up and I heard the startup chime, but it didn't get there and eventually the standby lamp started a slow, steady blink.
Opened her up and checked for standby voltage per shop manual (5v on pin 27 of CN100 on main board), which checked out OK. Then I checked for voltage elsewhere on CN100 and there was nothing.
Then I disconnected the cable between the power supply board and the main board and shorted between pin 3 "Standby" and pin 1 "Power On/Off" to see if I could find voltage present at any of the other pins on CMN802 (the connector on the PS board that partners with CN100 on the main board). Nothing.
Then I disconnected the two cables going to the back-light driver board, just to make sure it wasn't dragging the PS cold circuit down (so at this point the PS board was disconnected from everything else). No change.
From the stuff I checked on the hot side of the PS board, everything appears good there from a voltage standpoint, but I can't find voltage anywhere on the cold side of the board except for the 5V for standby.
Nothing appears untoward on the board except the 3 transformers look a little funky to my untrained eye - scorched/melted, or at least like they've been working pretty hard.
I'm a bit of a newb when it comes to troubleshooting down to the component level (it's sometimes quicker just to change out a suspect board) but I'm willing to learn if you guys have suggestions as to what I might check.
Opened her up and checked for standby voltage per shop manual (5v on pin 27 of CN100 on main board), which checked out OK. Then I checked for voltage elsewhere on CN100 and there was nothing.
Then I disconnected the cable between the power supply board and the main board and shorted between pin 3 "Standby" and pin 1 "Power On/Off" to see if I could find voltage present at any of the other pins on CMN802 (the connector on the PS board that partners with CN100 on the main board). Nothing.
Then I disconnected the two cables going to the back-light driver board, just to make sure it wasn't dragging the PS cold circuit down (so at this point the PS board was disconnected from everything else). No change.
From the stuff I checked on the hot side of the PS board, everything appears good there from a voltage standpoint, but I can't find voltage anywhere on the cold side of the board except for the 5V for standby.
Nothing appears untoward on the board except the 3 transformers look a little funky to my untrained eye - scorched/melted, or at least like they've been working pretty hard.
I'm a bit of a newb when it comes to troubleshooting down to the component level (it's sometimes quicker just to change out a suspect board) but I'm willing to learn if you guys have suggestions as to what I might check.
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