Badcaps.net Forum
Go Back   Badcaps Forums > Electronics Theory and Troubleshooting > Troubleshooting TVs and Video Sources
Register FAQ Members List Social Groups Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 08-12-2012, 11:58 PM   #1
sfdskins
New Member
 
Join Date: Jul 2012
City & State: north carolina
My Country: usa
I'm a: Knowledge Seeker
Posts: 8
Thumbs up 42" rca 42pa30rq no picture but sounds working

Hello everybody.
Got a problem with my rca plasma. came in the room with the tv on and found the picture was dead on the tv. sound was still working. with some help(service manuals) from Tom66 . thought i would try and fix it myself.
First off, when you plug the power into the tv, when it was working and i hit the power swich and you would hear one click from the power relay and the picture would come up. Now when i turn the power on, its one click, the several clicks on & off.
I checked for operating voltages at connector(cn804, to the y-main board) but no voltage present except the 15 volt.
I can pull this plug and it goes back to one click from the power relay, not sure if this means anything or not was going by the troubleshooting guide.

I did manage to find a component on the y-buffer board that appeared to be burnt,

im at a stand still now any help would be appriciated.
Thank you in advance.
sfdskins is offline   Reply With Quote
Old 08-13-2012, 01:44 AM   #2
tom66
Badcaps Veteran
 
Join Date: Apr 2011
City & State: Leeds (University)
My Country: UK
Line Voltage: 230Vac 50Hz
I'm a: Student Tech
Posts: 26,708
Default Re: 42" rca 42pa30rq no picture but sounds working

Can you show a picture of the burnt component? This plasma is essentially a Samsung re-badge.
__________________
Please do not PM me for help and support. Questions belong on the public forum.

68 LED/LCD TVs, 5 monitors, 26 plasma TVs, and 2 AVR 6.1 amplifiers saved from the dump!
Totally free service manuals database: http://www.toms-service-manuals.com/ (Contact me for requests or contributions.)

I have successfully fixed (from best --> worst build quality):
1 Pioneer KURO 9G, 10 Panasonic LCD/Plasma, 1 Sony LCD, 1 NEC Plasma, 2 Yamaha HTS, 4 Sharp LCDs, 5 Toshiba LCDs, 7 Philips Plasma/LCD, 1 Hitachi Plasma, 10 LG LCD/Plasma, 15 Samsung LED/LCD/Plasma, 1 Thomson Plasma, 1 Atec LCD, 1 Hanspree LCD, 1 Xerox LCD, 1 Harwa LCD, 2 Proview LCD, 2 Hyundai LCD, 1 "Onn" LCD, 1 Grundig LCD, 1 Dell LCD, 1 iiyama LCD, 1 Acer LED, 1 Logik LCD, 1 Baird (China) LCD, 6 Bush LCDs, 19 Vestel LCDs
tom66 is online now   Reply With Quote
Old 08-13-2012, 07:27 PM   #3
sfdskins
New Member
 
Join Date: Jul 2012
City & State: north carolina
My Country: usa
I'm a: Knowledge Seeker
Posts: 8
Default Re: 42" rca 42pa30rq no picture but sounds working

here is a pic of the component, it was under some silicon so i noticed the black spot and cut away the silicon to inpect it. its on the y buffer board.

thanks
Attached Images
File Type: jpg 2012-08-12 23.47.08.jpg (1.50 MB, 261 views)
File Type: jpg 2012-08-12 23.44.02.jpg (1.52 MB, 209 views)
File Type: jpg 2012-08-12 23.49.57.jpg (1.50 MB, 185 views)
sfdskins is offline   Reply With Quote
Old 08-14-2012, 12:50 AM   #4
tom66
Badcaps Veteran
 
Join Date: Apr 2011
City & State: Leeds (University)
My Country: UK
Line Voltage: 230Vac 50Hz
I'm a: Student Tech
Posts: 26,708
Default Re: 42" rca 42pa30rq no picture but sounds working

Test across those caps, deos it appear short circuit on ohms? (With power off.)
tom66 is online now   Reply With Quote
Old 08-14-2012, 04:03 PM   #5
sfdskins
New Member
 
Join Date: Jul 2012
City & State: north carolina
My Country: usa
I'm a: Knowledge Seeker
Posts: 8
Default Re: 42" rca 42pa30rq no picture but sounds working

it wasnt a dead short but did read about 10 ohms,
sfdskins is offline   Reply With Quote
Old 08-14-2012, 04:08 PM   #6
tom66
Badcaps Veteran
 
Join Date: Apr 2011
City & State: Leeds (University)
My Country: UK
Line Voltage: 230Vac 50Hz
I'm a: Student Tech
Posts: 26,708
Default Re: 42" rca 42pa30rq no picture but sounds working

I would advise replacement of the buffers - they are generally quite cheap because this model is ubiquitous, I believe they are also used in PS42B450 and PN42B450 if that helps.
tom66 is online now   Reply With Quote
Old 08-14-2012, 04:15 PM   #7
sfdskins
New Member
 
Join Date: Jul 2012
City & State: north carolina
My Country: usa
I'm a: Knowledge Seeker
Posts: 8
Default Re: 42" rca 42pa30rq no picture but sounds working

I was thinking about replacing the buffer board and the y main board but ill try the buffer board first, I believe i can get it for about 15 bucks, shouldnt be too bad
Thanks Tom
sfdskins is offline   Reply With Quote
Old 08-19-2012, 07:54 PM   #8
sfdskins
New Member
 
Join Date: Jul 2012
City & State: north carolina
My Country: usa
I'm a: Knowledge Seeker
Posts: 8
Default Re: 42" rca 42pa30rq no picture but sounds working

i replaced the y-buffer board (along with the logic board & the x-main sus board, got them for a good price)
still has the same problem black (dead) screen no picture, but sounds still working.

What im noticing is i cant read any voltages when i first power the tv and when i hit the power button, it the relays on the power supply board will click a couple times normally it was one click when tv was working. It does go to 15 volts dc but once the clicking stops it steadily goes down to 0. no other voltages present at any time.
Could it be a y-sus or power supply problem?
i can pull the power plug to the y-main board and the relays act normal just one click.
Thanks
sfdskins is offline   Reply With Quote
Old 08-20-2012, 02:33 AM   #9
tom66
Badcaps Veteran
 
Join Date: Apr 2011
City & State: Leeds (University)
My Country: UK
Line Voltage: 230Vac 50Hz
I'm a: Student Tech
Posts: 26,708
Default Re: 42" rca 42pa30rq no picture but sounds working

Sounds to me like the buffers damaged the Y-main; do you want to board swap or try and find the failed component?
tom66 is online now   Reply With Quote
Old 08-20-2012, 07:58 AM   #10
sfdskins
New Member
 
Join Date: Jul 2012
City & State: north carolina
My Country: usa
I'm a: Knowledge Seeker
Posts: 8
Default Re: 42" rca 42pa30rq no picture but sounds working

i wouldnt mind finding the bad component in case it does it again, but i will probably order a Y MAIN and try that to get it going, there is no physical damamge on the y board. i dont have a scope although i have access to some at work, getting to use them is another matter all together.

Do you think there is any need to get a power supply board when i order the y board?

Thanks
sfdskins is offline   Reply With Quote
Old 08-20-2012, 08:13 AM   #11
tom66
Badcaps Veteran
 
Join Date: Apr 2011
City & State: Leeds (University)
My Country: UK
Line Voltage: 230Vac 50Hz
I'm a: Student Tech
Posts: 26,708
Default Re: 42" rca 42pa30rq no picture but sounds working

Unplug Y-main and check Vs voltage; if it's stable around 190-210V, PSU is probably good.
tom66 is online now   Reply With Quote
Old 08-21-2012, 05:32 PM   #12
sfdskins
New Member
 
Join Date: Jul 2012
City & State: north carolina
My Country: usa
I'm a: Knowledge Seeker
Posts: 8
Default Re: 42" rca 42pa30rq no picture but sounds working

Tom,
i upluged the y-main power plug and checked the voltages, The excess clicking from the relay stops when unplug it by the way ,sonds like normal operation, When i cut the switch on, Vs voltage goes to a steady 207vdc and Va goes to 54vdc also steady, but after about 5 seconds the voltage starts to drop out or dissapate slowly to 0, this maybe be normal because where it doesnt see the y-main board? not sure.
sfdskins is offline   Reply With Quote
Old 08-22-2012, 10:26 PM   #13
sfdskins
New Member
 
Join Date: Jul 2012
City & State: north carolina
My Country: usa
I'm a: Knowledge Seeker
Posts: 8
Default Re: 42" rca 42pa30rq no picture but sounds working

Thanks for your help tom,
I got the y-main board in tonight, and that was the problem. My thinking on it is the y buffer board cap that was burnt, shorted out and took out something on the main board. what do you think? i had to reseat some connections to the ribbon cable on the buffer board because when the screen first came up had some black bars in line with the connections, was able to get that out and picture looks great now.
Might would like to look into it more and find the bad coponent on that board at some point but not ready to do that just yet,
Again thanks for you help on this, i learned alot about how thew tv works and feel cofident i can fix it again if i have another problem. Couldnt have done it without your help and the service manuals you got for me.
sfdskins is offline   Reply With Quote
Old 11-15-2013, 11:55 PM   #14
ezm420
New Member
 
Join Date: Nov 2013
City & State: Columbus NE
My Country: America
I'm a: Knowledge Seeker
Posts: 1
Default Re: 42" rca 42pa30rq no picture but sounds working

Hi sfdskins I have the same TV and same problem. Could you please tell me were you purchased your new boards? And think you for your posts they helped a lot.
ezm420 is offline   Reply With Quote
Old 11-16-2013, 02:26 AM   #15
capkid
Badcaps Veteran
 
Join Date: Oct 2010
City & State: Federal Way,WA
My Country: United States
Line Voltage: 120VAC 60Hz
I'm a: Hobbyist Tech
Posts: 1,204
Default Re: 42" rca 42pa30rq no picture but sounds working

Shopjimmy.com is your best bet. Their boards come with a 6-month warranty: http://www.shopjimmy.com/catalogsear...lt/?q=42pa30rq
capkid is offline   Reply With Quote
Old 11-26-2013, 02:19 AM   #16
dwdurko
New Member
 
Join Date: Nov 2013
City & State: Columbus NE
My Country: USA
I'm a: Knowledge Seeker
Posts: 1
Default Re: 42" rca 42pa30rq no picture but sounds working

Can you advise where to obtain a service manual for this model 42pa30rq
dwdurko is offline   Reply With Quote
Old 11-26-2013, 03:15 AM   #17
tom66
Badcaps Veteran
 
Join Date: Apr 2011
City & State: Leeds (University)
My Country: UK
Line Voltage: 230Vac 50Hz
I'm a: Student Tech
Posts: 26,708
Default Re: 42" rca 42pa30rq no picture but sounds working

No direct SM available, but the PN42B450 is a similar model and the service manual should be OK for that.
tom66 is online now   Reply With Quote
Old 11-26-2013, 06:02 PM   #18
Louis82
New Member
 
Join Date: Feb 2012
Posts: 14
Default Re: 42" rca 42pa30rq no picture but sounds working

Hello, I have a samsung pn42c450b1 that has no picture, no sound, it only clicks. Based on all the threads that i have read here, this tv has same circuit boards as RCA 42PA30RQ. I followed what some people have done and has worked them is replacing all 3 circuit boards. Y buffer, Y main and X board and still have same problem. At beginning i found that buffer board had a dark dot on a capacitor, removed glue and of course was physically burned.

Anyhow, i replaced all 3 circuit boards and still same. Any suggestion guys ? Is it possible that paylesscomponents.com sold me a defective board or is this a panel problem.

Thank you for your time and help.
Louis82 is offline   Reply With Quote
Old 11-28-2013, 04:09 PM   #19
capkid
Badcaps Veteran
 
Join Date: Oct 2010
City & State: Federal Way,WA
My Country: United States
Line Voltage: 120VAC 60Hz
I'm a: Hobbyist Tech
Posts: 1,204
Default Re: 42" rca 42pa30rq no picture but sounds working

Quote:
Originally Posted by Louis82 View Post
Hello, I have a samsung pn42c450b1 that has no picture, no sound, it only clicks. Based on all the threads that i have read here, this tv has same circuit boards as RCA 42PA30RQ. I followed what some people have done and has worked them is replacing all 3 circuit boards. Y buffer, Y main and X board and still have same problem. At beginning i found that buffer board had a dark dot on a capacitor, removed glue and of course was physically burned.

Anyhow, i replaced all 3 circuit boards and still same. Any suggestion guys ? Is it possible that paylesscomponents.com sold me a defective board or is this a panel problem.

Thank you for your time and help.
When you installed your replacement boards, did you install them all at once?
capkid is offline   Reply With Quote
Old 11-29-2013, 07:00 PM   #20
Louis82
New Member
 
Join Date: Feb 2012
Posts: 14
Default Re: 42" rca 42pa30rq no picture but sounds working

Quote:
Originally Posted by capkid View Post
When you installed your replacement boards, did you install them all at once?

Yes i did. Thank you
Louis82 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 04:09 PM.


Badcaps.net Technical Forums 2003 - 2014
Powered by vBulletin ®
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.

Did you find this forum helpful?