H & B Plasma ( Samsung guts) wont boot up

mookieo2

New Member
I removed from a customers house a 50" H & B Plasma that supposedly was broken. I brought it home, plugged it in and it worked . I checked all inputs. Everything was functioning fine. I even watched a movie on it. Once or twice it took a long time to boot up. An hourglass shows on the screen when its first turned on.

The next day and till now all I get is the hourglass really dim and then it starts clicking and eventually shuts off with an orange light on front.

First off I was an engineering tech at an aerospace company for a few years and a repair tech for a few years before while I was in school so I`ve done more than my share of soldering and troubleshooting. So I am capable of doing the repairs.

The main power supply pn I think is PS-503-D

I believe the voltage readings from the test points were
VA = 15v
VG = 0
VS = 7v
D5V = 5V before it shuts down
D3V3 = 3V before it shuts down
VSB = 5V

any help or link to schematics would be appreciated

I changed c 8072& 8073 1000uf 250v because the top was bubbled. After I replaced them I removed the black film and the aluminum underneath was flat
 
Check the ESR on ALL the electrolytics in the PSU - and replace any which are on the high side.

I poresume the replacements you've already fitted are high quality, 105 degree, low-ESR versions?.

If you don't have an ESR meter, then do a blanket swap of all electrolytics on the PSU for high quality ones.
 
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