RCA DLP m50wh72s

[Wizard]

Re: RCA DLP m50wh72s

Now that I"m home and with decent 19" LCD I can see more clearly (at my work aged 17" CRT samsung 2004 era). That area is buck regulator. It whined if there is poor capacitor. Ask them to check the capacitors there while changing out the incorrect capacitors. And my comment, HELLO? THIS IS SMPS board that needs correct capacitors STILL!

Cheers, Wizard

[mitchkramez]

Re: RCA DLP m50wh72s

hey guys, i just remembered i took this picture of the old caps before they were replaced... they're not of the greatest quality, but maybe someone can tell what they were?

[Krankshaft]

Re: RCA DLP m50wh72s

Those were Nichicons hope they were HN or HM series. There were bad batches in those series years ago.

[Wizard]

Re: RCA DLP m50wh72s

Just in, M50WH72SYX1 two of them needs bulbs and our supplier price is such that we have to sell at 700 EACH. Also it has 200 dollars core price!!

That's little extreme and seemly gold plated piece of POS lamp. Where compititors like Samsung have them out door for 300. Or you can find exact replacement bare bulbs for 1/2 that. Other than that, I do NOT like to have LCD panels, DLP with HID lamp (LED DLP is fine), and plasma is mercury reasons and cost of parts, especially DLP with HID lamp as it has life-limited lamp and color wheel as major issue, also LCD rear proj using HID lamp.

Be advised to look everywhere else for Osram lamp and swap lamp into your original lamp housing. My advice: BE GINGERLY. The heat and age on these 2006 housings made them incredibliy brittle as RITZ crackers. Best thing to do is take soldering iron and carefully heat one screw hot and unscrew it while hot.

Reassemble and don't tighten any further.

BTW, this is very old chassis and getting parts for it is rather bad.

Cheers, Wizard

[mitchkramez]

Re: RCA DLP m50wh72s

Wizard,
I think DM has the lamps for this TV for $109...

http://www.discount-merchant.com/Sea...earch=m50wh72s

Looks to be the same to me and their philips bulbs so they're better than OSRAM from my understanding...

[Wizard]

Re: RCA DLP m50wh72s

Issue is location. We're in canada and we have to keep paperwork and other things so we prefer to buy within canada.

Cheers, Wizard

[mitchkramez]

Re: RCA DLP m50wh72s

ah - makes sense, i hear customs can be a real bear when shipping from the states...

[mitchkramez]

Re: RCA DLP m50wh72s

well, i got the tv back, fm caps didn't help, still hisses, apparently that coil is bad, they resoldered it and siliconed it to the board, but apparently they can't get the part form rca anymore, or the power supply -- does anyone here have this power supply laying around they'd like to sell, or have a link to one? The part number (i think) is 270341R

[Krankshaft]

Re: RCA DLP m50wh72s

It may have resonated like that from the factory since the cap didn't cure it. I wouldn't waste the time unless the part was cheap or you know for a fact another working set doesn't hiss.

My many APC Backups UPSs inverter transformers hiss when they're running off the battery it's not a cause for concern but a normal occurrence.

It all has to do with the transformers design and the operating frequency of the switching circuit.

[Stang8URMPRT]

Re: RCA DLP m50wh72s

I am having the same problem with my M5OWH2S RCA, sometimes it will turn on. But sometimes it will click several times, and then the power light will flash. Eventually it will stop clicking and I have to turn the tv off and the back on for it to start clicking again... eventually it will come on. (meaning sound and picture comes on) I have had the TV on for over 2 months straight now in fear it won't turn back on. I just got my 55'' LCD today, so the RCA finally got turned off and now it's time to fix it. I have been thinking it was the ballast, and have read other places this could be the case... But have also read about the caps in the PS being bad. I can tell just by looking if they are bad? They basically just look swollen, right? Thanks for the help!


Nick

[mitchkramez]

Re: RCA DLP m50wh72s

Nick,
Yeah, most of the time you can tell if they're bad, the top will be puffy, if they're really bad you'll see stuff leaking out of the bottom on the caps. Here's a picture showing which caps were bad on my board, these are the most common ones to go:



They're highlighted in the red squares there. I had all four replaced even though only 2 of them looked puffy. I can't remember the numbers on the caps, but I think they were CP624, CP639, CP641, CP647.

Mine's been working great for 2 months since i had the caps replaced. My bulb has about 5000 hours on it at this point thought, so it won't belong before i need to pick up another one!

[Wizard]

Re: RCA DLP m50wh72s

Good!

Our supplier finally have a source of bare bulbs stock so we can now fix DLP sets quicker and within reason of price for customers. They are geniune bulbs.

Cheers, Wizard

[mitchkramez]

Re: RCA DLP m50wh72s

Wizard,
Do you recommend the Philips or the OSRAM bulbs?

[Stang8URMPRT]

Re: RCA DLP m50wh72s

Nick,
Yeah, most of the time you can tell if they're bad, the top will be puffy, if they're really bad you'll see stuff leaking out of the bottom on the caps. Here's a picture showing which caps were bad on my board, these are the most common ones to go:



They're highlighted in the red squares there. I had all four replaced even though only 2 of them looked puffy. I can't remember the numbers on the caps, but I think they were CP624, CP639, CP641, CP647.

Mine's been working great for 2 months since i had the caps replaced. My bulb has about 5000 hours on it at this point thought, so it won't belong before i need to pick up another one!

My board looks a lot different then that one, but I can tell it's basically the same thing... I have the TV apart now, and looking over it. I do not see any puffy caps or leaking caps... I did read to test the power wires to the ballast, and if it is less then 320V, then there is something wrong with the power supply. I tested mine (the two largest wires off the PS board with the tag stating "ballast") and it only reads 158ish volts. Any ideas? TV seems to be working ok the past day... It did give me two hick ups... I turned it on, and after about 10 secs, the power light blinked 5 times... then the screen lit up like normal. This happened twice.

I also noticed there is a small white "thingy" on the ballast, which lights up like a lightning storm seemingly when the ballast is firing to turn the bulb on. Is this just there to indicate the ballast attempting to fire?

Thanks!
Nick

[Wizard]

Re: RCA DLP m50wh72s

Always do exact replacement. Philips for philips or osram or osram unless the maker says it is ok to do so which is rare.

HID technology is very exacting design that it needs specific current when running and specific striking voltage, warm up time etc. Even two same 120W HID bulbs from philips and osram can be different to require different Lamp ballast.

Oh yes, run TV on low if it has option, this extend the life of HID lamp or change vivid or dynamic to standard or custom setting and adjust the brightness or light brightness down several clicks to just enough that it is still comfortable viewing even in daylight.

Cheers, Wizard

[mitchkramez]

Re: RCA DLP m50wh72s

nick, that small white thingy is supposed to spark like you're seeing. no worries. every tv is different, but you might want to see if Wizard has the correct voltage readings that should be going to the ballast - 158 seems low to me, but it's completely possible that that's normal - Wizard is the tv tech - not me... i just googled alot

[Stang8URMPRT]

Re: RCA DLP m50wh72s

nick, that small white thingy is supposed to spark like you're seeing. no worries. every tv is different, but you might want to see if Wizard has the correct voltage readings that should be going to the ballast - 158 seems low to me, but it's completely possible that that's normal - Wizard is the tv tech - not me... i just googled alot

Ok... Hey Wizard... Does it sound right? lol

[Stang8URMPRT]

Re: RCA DLP m50wh72s

I was measuring incorrectly. I have 335 volts at start up to the ballast. Everything else seems to work fine. When the ballast does decide not to kick the bulb on the first try, the power button blinks 5 times... then retrys (as indicated by the white "thingy" that lights up... then the bulb turns on.... So I believe with the correct start up voltage... my problem lies in the ballast... I will let you all know if the TV fails all together to start and what the fix is (if there is one).

Nick

[kc8adu]

Re: RCA DLP m50wh72s

lamp may be eol.they often do not strike reliably when worn out.
just did a panasonic i got free.it took 12 tries at startup to go.lamp looked fine so i did the ballast upgrade kit.better but still bad.
new lamp strikes on the first tick of the ballast.

[Wizard]

Re: RCA DLP m50wh72s

Correct, When you don't know the hours on the lamp, advise to test it with a new lamp.
Lamp can be sold to someone else if cannot fix a TV within reason (not wish to invest too much so to say).

Yes the small white cylinder with metal endcaps should flash/arc few times as lamp begins to strike. This thing is called spark gap.

DLP TVs will not strike the lamp (no sparking noise) if color wheel is not sensed. (stuck or not up to correct rpm).

We had a DLP TV that had lamp strike (warm glow for a 2 second) then goes out. Tried lamp and ballast, carefully checked the color wheel. We will not know the fix because this is on estimate and we feel it will be turned down since the DMD board swap required is costly because this unit is 4 years old, soon 5.

Cheers, Wizard