Samsung PN60E550D1FXZA Won't power on

[MagicSmoke]

Re: Samsung PN60E550D1FXZA Won't power on

PS-on volts read 4.2v connected or disconnected when AC volts applied.

Going out for dinner will check back in a couple hours. Thank you for taking time to point me in the right direction.

[tom66]

Re: Samsung PN60E550D1FXZA Won't power on

VS ON or PS ON...?

[MagicSmoke]

Re: Samsung PN60E550D1FXZA Won't power on

PS-on pin on main board connector reads 4.2v when AC volts applied. This was when I had it out of chassis and no jumpers connected.

Sorry VS-on reads 5.2v when AC volts applied with no jumper. Mis-read first time.

[tom66]

Re: Samsung PN60E550D1FXZA Won't power on

Ok, you need to have PS ON jumpered to get Vs/Va, sorry for not making that clear.

[MagicSmoke]

Re: Samsung PN60E550D1FXZA Won't power on

Ok re tested w/ X & Y mains disconnected from PSU and other boards as indicated in post 19. PSU connected to main board and jumpered ps-on to ground.

VS on = 0v

VS-con =2.96v

VS = 6v

VA =0v

Bad PSU??

[MagicSmoke]

Re: Samsung PN60E550D1FXZA Won't power on

Main board or PSU?? If I test w/ ground probe on - leg of main filter caps I get 57v on all pins except ground. I think PSU is toast.

[tom66]

Re: Samsung PN60E550D1FXZA Won't power on

VS ON is not present, which is odd, can you try connecting VS ON to 5V with a wire? on the same connector as PS ON.

Your 57V on -ve leg is OK.

[MagicSmoke]

Re: Samsung PN60E550D1FXZA Won't power on

Will do, I am at work right now so it will be 2-3hrs before I can get back to it.

[MagicSmoke]

Re: Samsung PN60E550D1FXZA Won't power on

Ok re-tested w/ VS-on jumpered to 5.3v and get

VS=247v should be 211v but I suppose it's high from no load?

VA=56v close should be 57v

Noticed that light inside optical output on main board is now lit when I tested for voltage.

[MagicSmoke]

Re: Samsung PN60E550D1FXZA Won't power on

Been doing more testing, specifically the function joystick. Page 5 of the Fast track troubleshooting guide says should have 3.3v on pin 3 of connector. I have 6v which drops to 0v when switch is pressed. 6v returns after release. This is in standby mode w/ no jumpers hooked up.

I am thinking main board is faulty now considering I get VS & VA volts when VS-on is jumpered. Am I thinking correctly? Thanks.

[tom66]

Re: Samsung PN60E550D1FXZA Won't power on

Can you try turning the Vs adjustment point because that is quite high for Vs... Otherwise it seems like your main board OR control board is bad, it is hard to be certain.

[MagicSmoke]

Re: Samsung PN60E550D1FXZA Won't power on

Will try to adjust Vs, I am about to go to work so it will be a little while before I can post results.

I found a main board for 28$US and a logic for 30$ matching my P/N's so I ordered them. As I am only into this at 158$ for a 1500$ tv, I figured what the heck.

Thanks for your help Tom. Will post results when parts arrive.

[MagicSmoke]

Re: Samsung PN60E550D1FXZA Won't power on

Got the replacement main and logic boards installed, and am making progress. Unit will now turn on and off with button and remote, can hear beeps when pressing volume up or down, but still no display.

LED on logic board flashes slowly when all boards connected, still has problems. VS and VA come up when powered on but then instantly start to fall. Unplugging LVDS cable and power to Y main gets the LED flashing like it's supposed to.

Pulled Y main and upper and lower buffers to check for shorts as shown on Youtube, but my boards don't have the same connectors like the ones being tested.

Main test points SVC YOUT, Vscan, SVC_VS, are not shorted to chassis ground or SVC_GND. None of the Power or LVDS connector pins show any shorts to GND except the GND pins which are supposed to. Not sure what to test next.

Will post pics of Buffers and Y_Main in a few min as my camera is charging now. Any idea's about what to test next?

Can the Panel be shorted causing the fault? Thanks in advance.

[tom66]

Re: Samsung PN60E550D1FXZA Won't power on

You can test from SVC_OUTL to the ribbon connectors. It is possible for the panel to be bad due to micro fracture.

[MagicSmoke]

Re: Samsung PN60E550D1FXZA Won't power on

Just checked all of Y buffer ribbons on panel for shorts to chassis and got no tone on any of them.

Is it possible to test the individual Y buffer ribbons on the panel for shorts? None look cut or rubbed.

Checked both buffers from SVC_OUTL pad to each side of all connectors and got no tone on any of them. And no tone between SVC_OUTH and SVC_OUTL.

Hoping its something on YMAIN. Can I power up YMAIN without buffers installed to check Vscan and VE on XMAIN without blowing either one?

[tom66]

Re: Samsung PN60E550D1FXZA Won't power on

Just checked all of Y buffer ribbons on panel for shorts to chassis and got no tone on any of them.

Is it possible to test the individual Y buffer ribbons on the panel for shorts? None look cut or rubbed.

I have never been able to do this successfully, however I have found that the modern panels will almost always blow the buffers when the panel is smashed.

Hoping its something on YMAIN. Can I power up YMAIN without buffers installed to check Vscan and VE on XMAIN without blowing either one?

Yes, you can do this with no harm.

[MagicSmoke]

Re: Samsung PN60E550D1FXZA Won't power on

This is with Y main disconnected and no buffers installed.

Might be on X main. VE test point shows only 15v when powered on, should be 98v. X main connected to buffer during test.

SVT_VS on X main test point shows 207v.

SMPS VS test point has 212v stable and VA 56v stable while TV powered on. Label shows VS 211v and VA 57v.

They stay stable until powered off with remote. LED on logic board blinks normal when on.

If Y main is connected to LVDS cable and power, VS and VA shut down instantly. LED blinks slow when on. No buffers connected to Y main at test time.

Got the same results as with buffers connected to Y main as in earlier test.

Pulled out X main checked for shorts to GND on all pins and test points, none found. Have not removed X buffer board yet to check.

Will remove X buffer as soon as I figure out the removal process for the ribbon cables. Thanks.

[MagicSmoke]

Re: Samsung PN60E550D1FXZA Won't power on

Got X buffer out, no shorts found.

[MagicSmoke]

Re: Samsung PN60E550D1FXZA Won't power on

More testing on X main, VE test point shows 16v (should be 98v) but VE out to Y main only shows 3v at connector going to Y main.

No caps look bad, (no bulging) I do not have an ESR meter. No other components show any signs of heat or physical damage.

SVT_VS on X main still shows 207v. X main connected of course to PSU and to LVDS cable. This test was with Y main disconnected from both.

So it looks like X main is not making the right voltage to turn on Y main when it is connected. Am I correct in thinking this?

[MagicSmoke]

Re: Samsung PN60E550D1FXZA Won't power on

More testing, Y main connected to X main power but not to LVDS. X still connected to LVDS.

PSU stays on w stable VS at 211v, VA at 57v. Logic led blinks normally.

SVC_VS test point on Y main shows 211v. No buffers connected to Y main.

SVC_YOUT shows -44v.

Vscan shows -58v fluctuating to -44v. Should be -198v.

VE on X main came up to 19-20v. Should be 98v

Bad X main or Y main or both?? Cannot see any components damaged or obviously blown. Anybody got any ideas? Thanks.