Great, another y-scan-only-to-fix!
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Viz
Member
Last Activity: 11-20-2014, 02:00 PM
Joined: 10-20-2014
Location: Saratoga NY
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Re: RCA 42PA30RQ Sound but no picture
Great, another y-scan-only-to-fix!...
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Re: RCA 42PA30RQ Sound but no picture
Y-scan board [ The above video calls it a Y-buffer board ]...Last edited by Viz; 11-11-2014, 09:56 AM.Leave a comment:
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Re: RCA 42PA30RQ Sound but no picture
[B][COLOR="DarkGreen"]tom66[/COLOR][/B],
[U]Multiple thanks for the help[/U]. Got the new board, checked the pins (as per video), and installed. Works fine now.
[B]unboltedoak[/B],
I am not an expert but followed various posts on this forum. Noticed a number of multiple clicking posts. My set just has a double-click at the start (too much Microsoft Windows perhaps ...) which is normal for it.
[B]1st[/B], visually inspect for any blown/burnt components and/or...Last edited by Viz; 11-06-2014, 07:54 AM.Leave a comment:
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Re: RCA 42PA30RQ Sound but no picture
Well, since didn't have a way to remove the chip, used a razor blade to cut and scrap off the pins. Now have a TV with 2/3 a picture - but who needs to see the sub-titles anyway.
Too bad I didn't have the tools to replace that sort of chip. Will order a replacement board for ~$30 and it should work ... then time to celebrate
Still I pose the question: [B][U]Are there things that can go wrong with the panel itself that can cause this sort of failure[/U][/B]? (beside having a Wii thrown at it) Seems they just...Last edited by Viz; 10-31-2014, 08:58 AM.Leave a comment:
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Re: RCA 42PA30RQ Sound but no picture
That makes sense. Now to figure out how to remove the chip cleanly ... my iron may be too small but my torch for HVAC brazing is too hot
Is there a possibility the panel itself caused the chip to blow? Is there a way to test panel lines (or are do they just go safely blank?)Leave a comment:
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Re: RCA 42PA30RQ Sound but no picture
Sorry, seem to be getting the wrong terminology.
Removed Y scan drive board [ LJ92-01739A ]. Set meter on ohms. Black lead on board ground. Then test each (and every) ribbon connecter pin (several hundred). About a dozen pins are < 1 ohm (shorted) -- all foils are to U5506.
Barring anything else is wrong, it is just that chip. I don't have equipment to desolder it. Would like to remove it and then test panel with the one ribbon not connected. It would demonstrate if Y-main is fine (just a big blank bar in the...Last edited by Viz; 10-30-2014, 05:36 PM.Leave a comment:
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Re: RCA 42PA30RQ Sound but no picture
My bad: Vs=207 and Va=55 for 2 seconds then fades to zero. Doesn't matter if Y+X boards are connected. PSU probably fine. Also, no shorts for Vs or Va.
Definately a bad Y sustain. While there is nothing visable to see, it fails testing. It has 8 ics (shift registers??) connected to 6 ribbon connections. The 2nd connector (and IC)from bottom has shorts to ground. The position corrosponds to the visual portion of the screen where the volume level is shown. It failed when pressing volume on remote ... so it looks like that was the...Last edited by Viz; 10-30-2014, 01:53 PM.Leave a comment:
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Re: RCA 42PA30RQ Sound but no picture
Thank you
Yes, Vs is 207 for about 1 sec then fades away. However Va is always absent - floating near zero. Since only 1 connector has these two voltages and the connector is removed, then ether Va is dead on the supply or it doesn't come alive unless told to do so (and it isn't being told).
The 'logic main' pcb has a green led that flashes on for 2 seconds then off for 1 second.
In your tutorial you mention Y and/or Z boards usually being suspect on blank screen. In a link provided [ [url]http://www.shopjimmy.com/catalogsearch/result/?q=42pa30rq[/url]...Leave a comment:
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Re: RCA 42PA30RQ Sound but no picture
Supply part # RF09231-20120517
Note: Disconnected power to Y-main. Upon startup, vs is over 200 but then drifts down to nothing.Last edited by Viz; 10-27-2014, 02:36 PM.Leave a comment:
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RCA 42PA30RQ Sound but no picture
Was watching but as soon as pressing volumn control (remote) there was a pop in the back of unit and picture disappeared. No odor. Sound is fine. Sometime there are white dots (coarse 'snow') on the left (mostly upper-left) side. No heat.
Unit starts with the usual double-click. Inside label: Samsung S42AX-YB09 manufactured May 2012
Don't see anything that looks burnt/'popped'
Power supply: 15.4, 5.2, 3.3 (vs), 0 (va) [ no video signal applied ] Not finding any high voltages.
Looks like the power supply, but hey, stranger things have... -
Re: New Members - please post your introductions here
Greetings Earthlings and others,
Am an old computer guy who started dabbling in electronics somewhere between diapers and puberty. About the time man first landed on the moon.
Much of this world is throw-away, so am glad to find this forum. Generally limit repair work to changing boards or obviously exploded components. At least I can try, get mad, and then throw it away ...
Look forward to learning how you all function on a planet filled with bad capacitors.
CraigLeave a comment:
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