Sony KP-57HW40

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LabParents
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Sony KP-57HW40

No picture. No sound.

In testing the outputs from G board (power supply) to both A and B boards are reading erratically. The readings are not as the tech manual states.

Is replacing the G board the way to go or is there a different solution?

Thanks!

Larry Dillon
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That is impossible to say

That is impossible to say without having the voltages, where you took them from and what the symptom of the set is. How many times does the light blink on the TV set?

LabParents
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When the set is turned on the

When the set is turned on the light blinks six times.  There is no picture or sound to the set but there is a clicking sound (4 clicks) when the set is turned on.

 Output to D board

+135 volts reads +15.9mV

+22 volts reads +13.26V

-22 volts reads -18.7V

+15 volts reads +83.5mV

-15 volts reads +80mV 

Larry Dillon
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There is a short in the set.

There is a short in the set. That is the power supply trying to start up and then finally shutting down. The most common things in this set to cause this symptoms are the horizontal output transistor being shorted, or the convergence IC's being shorted, or the power supply itself being bad.

LabParents
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I have tapped the power board

I have tapped the power board and have had different readings (not the ones I provided) and none of them are what they should be.  The information you provided helps me, I will look into theses options (surely will be back).  I am grateful to have this narrowed down, thank you.  Have a great week!

Larry Dillon
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what you can do is first

what you can do is first disconnect a couple of the plugs from the G board ( the power supply board) and see if the 135 and the 22 volt lines come back up. If they do then you know the problem is in the D board. if they do not, then you isolated the problem to be in the G board.

LabParents
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The first thing I did was

The first thing I did was unplug the two A boards and the D board.  My readings are as follows:

 First readings to A board:

stand by -5V read 5.60v 

Relay read -0.48v 

OCP read 033.9 mV

OVP read 033.9 mV

Second readings to A board:

- 5v Zero straight across

6v  -014.0 mV 

11v -014.9 mV

D board:

+135v  reads -000.5 mV

+22 v reads 000.5 mV

-22 v reads -000.3 mV

+15v reads -000.2 mV

-15v reads -000.2 mv

 * * *

With first output to A board plugged in, D board reads: 

 +135v  reads 000.1 mV

+22 v reads 00.1 mV

-22 v reads 00.10 mV

+15v reads Zero straight across

-15v reads -001.0 mV

 With second output to A board plugged in, D board reads:

+135v  reads 0.5 v and falling

+22 v reads 26.6v

-22 v reads -26.37 V

+15v reads 297 mV and falling

-15v reads280 mV and falling

Thanks again for all your help! 

LabParents
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Sorry, I was unclear.  The

Sorry, I was unclear.  The readings I provided were were outputs from the G board.

Larry Dillon
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If everything was

If everything was disconnected from the G board, and those were the readings you got, send the entire G board to ptscorp.com. They will overhaul it for you.

jd5449
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larry I have a kp-51hw40 it

larry I have a kp-51hw40 it blinks 5 times i have read the blink code from forum but i also have a sony schematic for my kp-57ws520 and it tells me something different  ck ic452 and ic9101,02,03 on the cr boards i erased the old codes that were in the tv and reset every thing back to factory but the problem I am having is the tv after about a min it start turning red  i believe it's the bulb but are not sure do you happen to have the schematic .    

Larry Dillon
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You do not need a schematic

You do not need a schematic to diagnose this problem. The picture tube is bad. Very very common problem. I have heard the picture tubes are no longer available and if they were it would not be worth replacing the tube, as labor and the tube would cost you about 500 bucks or so. Good Luck

jd5449
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thank you  larry.I have no

thank you  larry.I have no problem doing it my self if the part can be founded

LabParents
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Thank you for your help and

Thank you for your help and for the referral to pts.com.  As a Hoosier, it is nice to keep the work in my home state.

Larry Dillon
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Thats great your From Indiana

Thats great your From Indiana too. I was originally from Indianapolis. I now live in Northern Michigan. Good Luck

Larry Dillon
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jd, problem is though that

jd, problem is though that once you replace a picture tube on an older set, you will never be able to get the right grey scale so the colors will always be more overridding of the tube you replaced.

jd5449
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so how would i fix that  with

so how would i fix that  with the color overriding  or should i just try to find a used tube

Larry Dillon
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You maybe able to find a used

You maybe able to find a used tube. get the number and lok around on e-bay for peeps that have had other problems with their TV sets.

Bwillig
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My Sony  KP 57hw40 turns on
My Sony  KP 57hw40 turns on to a blue screen, gets dim, then goes off. The light on the front flashes 8 times. Is it fixable, or just trash it?
 

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