Riddled TV Repair Forum

tray2100 · Joined: 10 Jan 2010 Posts: 14 Location: Toronto

Hey,

My beloved RCA D61130 won't turn on. I did some research online and came across some thomsen docs which have kinda helped me narrow the problem down to the run power supply.

When I press the power button on the TV, pin 4 on the U13101 micro goes low and I can hear a click as the tv tries to start up but the tv doesn't start, the system repeats this two more times before it gives up.

Since I have the correct voltages at the micro based on what i've gathered from google searches and measured with my multi meter, I can fairly confidently say that the stand by power supply is okay.

Any suggestions on how to diagnose the issue with the run power supply? schematics for it and\or troubleshooting tips\guide are practically non-existent online.

Any suggestions would be MOST appreciated! I love this TV

Google

JTS1957 · Joined: 21 Jan 2009 Posts: 1330 Location: Far, Far Away

http://www.eserviceinfo.com/download.php?fileid=38032

tray2100 · Joined: 10 Jan 2010 Posts: 14 Location: Toronto

Hey,

Thanks for the reply!

I already have that download. Those docs help me trace the problem to the "run power supply". There is a flow chart for diagnosing the stand by power supply system for the CTC211 chassis in those docs but not the run power supply. Bundled with those docs is a power supply doc (which seems to outline the main power supply) but its for the MM101 chassis and the pdf file is formatted differently from the pdfs for the CTC211 chassis so I know they're not from the same book.

Are the MM101 and CTC211 similar (or the same)? Can I use the points in that MM101 pdf to diagnose the run power supply issue?

The next point is that the pdf for the MM101 is more of a functional guideline rather than an troubleshooting guide. Any suggestions on common things to check with regards to a "run power supply"?

JTS1957 · Joined: 21 Jan 2009 Posts: 1330 Location: Far, Far Away

"Unlike the standby power supply, the run supply has a switched raw B+ that is controlled by the SysCon. Like the other ZVS power supplies, Q100 is the switch and functions the same as Q601 in the standby power supply. Feedback comes from the +68Vr and controls the on/off cycle of Q100."

tray2100 · Joined: 10 Jan 2010 Posts: 14 Location: Toronto

Alright just as a quick update, I tested Q14601 and Q14100 and i'm getting 165 on the G D and -165 on the S D of both transistors.

I'm not a novice at electronics (i'm in my undergrad in computer engineering) but I've never attempted a repair like this before. Suggestions?

Is there a pinout for the transformer? or a schematic of that area I can use to verify connections, voltages, etc...

I'm assuming that theres a shorted component somewhere but I'm not certain on how I should proceed further.

Google

kuhurdler · Joined: 28 Dec 2006 Posts: 2571 Location: Overland Park, KS

As an engineer myself, let me give you a little tip I have learned over the years:

When you're talking to non-engineers, don't try to qualify yourself by saying you're an engineer. It doesn't buy you anything, and it often rubs people the wrong way. Some even take it as arrogance.

I blame it on paper-mill colleges/universities giving any idiot an engineering diploma. Colleges would rather take their money for 4+ years than flunk the worthless students that deserve it.

Just ask intelligent questions with humility and respect. Your good questions will qualify your expertise.

tray2100 · Joined: 10 Jan 2010 Posts: 14 Location: Toronto

Hey,

I truly didn't mean to rub anyone the wrong way. I said that only to provide a point of understanding of my experience level. This is why I concluded the sentence by saying that I've never done anything like this before.

I take and appreciate your advice!

So now like a novice, I believe I shorted something while I was probing voltages around Q14100 and now the AC Fuse keeps blowing. Without a schematic, I'm not certain where to begin my search.

Any suggestions?

Jesse Mack · Joined: 22 May 2008 Posts: 600 Location: The Last Frontier

Does the AC line fuse blow on plug in or when you turn the set on?

Jesse

tray2100 · Joined: 10 Jan 2010 Posts: 14 Location: Toronto

On plug in ....

Jesse Mack · Joined: 22 May 2008 Posts: 600 Location: The Last Frontier

Check CR14202 Bridge and Q14601 and by testing I do not mean checking to see if there is voltage on them. Check for shorts.

Jesse