Re: 60PB5600 no picture
Finally the parts arrived, and now my TV Is working again.
Thanks for your help Jeff.
Srtech
Member
Last Activity: 08-23-2023, 01:32 PM
Joined: 01-26-2017
Location: Prince Albert, sask
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Re: 60PB5600 no picture
Checking Y-sus board R559 I found it open just like yours.
So I ordered the parts that you replaced and will let you know the results.Leave a comment:
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Re: 60PB5600 no picture
Hi Jeff, thanks for your post and solution. My TV is still waiting for me to fix it, but now I may have time to follow your lead.Leave a comment:
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Re: 60PB5600 no picture
Here is an update on this TV.
I found some boards to swap and started with the buffers. I changed them both, but it made no difference.
Next I got ahold of a P/S, control board and another y-sus board. Turns out the y-sus is bad, as it doesn't produce any voltages at the buffers, and does not even prime the screen. (No white flash at power up.
The second power supply doesn't work and I noticed a fuse is missing off the board!
The second control board seems to function, as it has the same four flashes of the LED but no improvement for...Leave a comment:
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Re: 60PB5600 no picture
Could the problem be the Ctrl board?
I'll check for voltages tomorrow and inspect it for obvious faults.Leave a comment:
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Re: 60PB5600 no picture
So here is an update.
I found another meter that measures small capacitors, and C975 from the bottom buffer board measures 2nf in circuit and 1.5nf out of circuit.
The closest value I have is 16nf so I put that one in place of the blown C873.
It made no difference to the tv, it still has no picture.Leave a comment:
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Re: 60PB5600 no picture
Well these smd caps are touchy little things to play with. First they have no markings for values, then my meter doesn't measure in the nf range. Schematics are difficult to track down so identifying values will take some work.
I have some smd caps on scrap circuit boards from other devices, but not knowing the values bothers me.... What method do you find works best for soldering/desoldering these devices?
I found used driver board ERP77186101 for $40 but I really want to learn how far I can go in board level repair. Kinda testing...Last edited by Srtech; 02-11-2017, 08:54 PM.Leave a comment:
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Re: 60PB5600 no picture
So for resistance two are open (C873 & C975) and C956 measures 5k.
C873 is broken also.Leave a comment:
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Re: 60PB5600 no picture
Sounds good Hamie, thanks for spending some of your evening on this. What values should those smd caps be?Leave a comment:
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Re: 60PB5600 no picture
Yes I see three caps and measure two at 0.01uf (shorted I assume) and one at 35uf. One is blown apart also!...Leave a comment:
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Re: 60PB5600 no picture
Yes I get the flash (prime as I have learned)Leave a comment:
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Re: 60PB5600 no picture
Like this?...Leave a comment:
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Re: 60PB5600 no picture
Ok the vy voltage reads 187v DC and is the same with both buffers disconnected.Leave a comment:
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Re: 60PB5600 no picture
I am not sure where vy is accessible as I don't see a clear identification on the y-sus board.
However at GR 170 = 84.7v
And at GR250 = 271v, since they are marked as vy - and vy+ respectively, I assume vy is the difference of 187v. It is the same with the buffer disconnected.
With buffer connected vsc = 235.3v measured at P152, but with the buffer disconnected vsc = 0v at P152.Leave a comment:
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Re: 60PB5600 no picture
In addition Imchecked the following voltages at the power supply connector P813
M_on = 3.06v
RL_on = 3.1v
5.2 = 5.2v
17 = 17v
AC_on = 5v
17v_det = 2.5v
VS_on = 3.07v
vs_det = 2.5vLeave a comment:
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Re: 60PB5600 no picture
Ok, so after looking at the other messages on this tv, I did more checking.
Voltages on y-sus board at P152 connector are:
Vpp = 235.2v
Vsc = 235.2v
5vf = 90v
Sus_on = 85v
On P151 at pin 7 there is "15vf" = 100v
Va on the power supply = 54.7v and the same on the z-sus board.
I checked the four igbts Q401, Q404, Q405 and Q406 and none are shorted but test as diodes.
So should I be looking at a Main Board? I have white screen flashes at power up, and sound is...Leave a comment:
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Re: 60PB5600 no picture
Ok so here are a set of pictures.
Measurements are vsc on P152 is at 235.7 vdc, and vy on the test point is 85.4 vdc....Leave a comment:
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60PB5600 no picture
I am just learning about Plasma and LCD/LED TV's and have an LG 60PB5600 that turns on but no picture or menu. It does power up with a white screen flash. The blue indicator light on the front of the set flashes when I press the menu button, but no menu appears on the screen.
The vs and va voltages are according to the label as are all voltages on the connector to the main board. (RL_on =3v)
After reading other posts, I tried getting the test patterns but no success. I jumpered EXT_AUTO_GEN, unplugged the blue ribbon from the main board, unplugged P231 from the main... -
Re: New Members - please post your introductions here
Wow this forum has so many experienced folk. I have already gotten good information to help fix some flat screen TV's so decided to join and see what else I can learn.
Basically retired from many years in technology. I hold a very old Computer Engineering diploma, have worked on hardware ranging from broken wires, up to optical tape recorders using lasers etc. I learned a little programming in various languages but I enjoy fixing anything and lately have been looking into TV's. Now the CRT tubes are gone I'm not...Leave a comment:
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