LG 42PT250 - TA not turn on

[maxvalutech]

Usual problem so checked power board over and all looked OK fuses diodes etc. Voltage on main caps good at 345v. Standby OK but little else. Checked voltages for turn on with meter connected and signals from main aok. No Vs at all and feed is via X so disconnected lead to Y and switched on - voila 201v sot on. Y sus is E52483 and covered in the gooey gunk from manufacturer. Question 1 can I test sus with buffer removed without damage. 2 any known bad components on this board in your experiences. Thanks in advance.

[maxvalutech]

Re: LG 42PT250 - TA not turn on

Can anyone assist here?

[ReeceyBurger123]

Re: LG 42PT250 - TA not turn on

If you did some research youd find the answer out lol

[maxvalutech]

Re: LG 42PT250 - TA not turn on

Well given a number of recent posts someone on here needs to search for an article on how to keep your mouth shut if nothing worthwhile to say. I have found the search on this site to return too many non relevant posts but do recall one some time ago that suggested ysus could be damaged if buffer not attached. Also seeking any help re this board from people with far more experience of LG plasma model.

[maxvalutech]

Re: LG 42PT250 - TA not turn on

Pic attached

[dskall]

Re: LG 42PT250 - TA not turn on

Have you checked buffer for shorts?

[maxvalutech]

Re: LG 42PT250 - TA not turn on

Will have to research test method and get back. Did try for VS with buffers removed but no go although protection may then have kicked in.

[maxvalutech]

Re: LG 42PT250 - TA not turn on

I did do test on buffer by probe on a ysus input connector pin and other pro e run along all the screen output pins - no reaction from mm. Not worked on LG plasma before but have done several Samsung and recall their buffers had test points but nothing marked as such on this buffer. Ysus board in short supply it seems.

[Andrew F. Ali]

Re: LG 42PT250 - TA not turn on

You could disconnect the Y-sus Bd from the PSU and connect a 230Vac light bulb as a load to the PSU connector supplying the Vs voltage to the Y-sus Bd and apply power the light bulb should glow bright, if the PSU is good. You could measure Va to confirm a working PSU.

[maxvalutech]

Re: LG 42PT250 - TA not turn on

Andrew F post prompted me to check Va as I didn't do that when it seemed obvious the problem was with Y side board/s. So I disconnect lead X (Z) to Y and test Vs and Va. Surprise now I get nothing with set clicking on off. In frustration I disconnect lead from power board to X and both Vs and Va come up stable at power board connector albeit my meter shows them a few volts over Vs 201 reads 209 and Va 55 reads 58. Back to the drawing board!

[Kamranali]

Re: LG 42PT250 - TA not turn on

Hi Maxvalutech
I have same board problem burn some parts and cannot see the number also
I saw your picture att post here may i know the parts number Ey706 and Ey704 please reply thanks

[Kamranali]

Re: LG 42PT250 - TA not turn on

Please send me the tow transistors number coz my transistors burn and cannot ready the number

[maxvalutech]

Re: LG 42PT250 - TA not turn on

Luckily still have this and both appear to be....
IRG7IC28U P106D and on bottom line 53 V8
Also note a video is on YouTube about replacing these in another model LG