Entertainment Center: TVs, Stereos, VCRs and DVDs - samsung CRT projection tv smells hot, won't come on

Hello,

I was given a samsung HC-P5252W 52" rear projection TV. The folks that had it said it was 3 years old. They said it just quit and they went out and bought another. I took it home and opened it up. I plugged it in and it wouldn't come on, but I could hear something power up (the flyback?) with a high tension whine. I heard the speakers click, but nothing else. I left it on for a while and started smelling something. I noticed the convergence IC chips were getting hot, and looked like one was maybe starting to smoke a bit. This was all with the power off? Anyway, I checked the board with the IC chips and heatsinks and saw 4 resistors that looked like they were getting a little hot too. RZ125, 126, 127, and 128. I have no manual or schematic for this tv. I'm not an electronics repairman, but I have a small amount of basic experience with electronics. Does anyone here have any experience with this problem, or suggestions?

I don't have access to the service manual on this set.The main power supply on these sets is running all the time in a ready state to give an instant on.I would pull the convergence ics out of the circuit and then see if the power supply scream stops.If it does the set may even power up but will have a bad picture.
Let me know what happens.:)

Thanks for the reply,

Let me clarify...the "whine" I described is not constant, it's just a power-up whine (for lack of a better description). It's the normal little high pitched noise you hear when you turn on any regular TV set. You hear the click of the relay, the short, faint, high pitched noise, then some static sounding crackle as the picture comes on. (but in my case, the picture doesn't come on...hitting the power button does nothing). That's the high pitched noise I'm hearing.

Based on this, do you still think I need to pull the ICs? If so, I'll plan to do that this evening.

I would go ahead and pull the ics.They are the most common failure on projection sets.

Ok, I pulled the ICs and still have the same symptoms, other than the smelly hot IC symptom. The light by the power button is on (which according to the owners manual, the light should be on when the set is off). When I hit the pwoer button, nothing happens. I jumpered the power button to eliminate the button as suspect, but with no difference.

What would you look at next? And thanks for the advice so far.

Well without diagrams luck is on your side.
Check this out: Part Number: BP94-01266A
Division: TV
Description: PCB-PWR DEF/INCL. FLYBACK/CONV AMP ICS
Stock Availability: Item usually ships in 3-5 business days.
Price: $189.15

You can get the whole module and at a reasonable price!

Great! Thanks for looking that up!

Are you pretty confident this will solve the problem? Does it matter where I buy it as far as quality? I mean, there are several places that sell them from $139.00 to over $200.00...all of them have the same part #s. Are they all the same?

Some may be "brand new" some may be "rebuilt".If it's brand new the cheaper the better.:) If it's rebuilt it depends on the company that rebuilt it.Check the warranty.90 days is usually a good one.:thumbup:
That should fix any power problem the set has.Not bad for a 3 year old freebie.

Ok, i got a new one for $148.00 and it should be here friday. I'll report back when I get it in. Hopefully all will be well. Thanks for the help!

Ok, got the new board in and it works!! Thank you very much!! I noticed the ICs are smaller and a different brand than the old ones. Maybe they have corrected the problem and installed updated ICs.

I have no sound now for some reason. We had it, but we walked away from it and came back and there was no sound coming from the speakers. We checked the obvious stuff, but no dice. I guess it's not a terribly big issue, since the sound will be coming from a receiver anyway, but it should come from the speakers when they are turned on.

I plan to get an original remote for it, and a copy of the owners manual.
Thanks again for helping me get this set working!

Ok, after watching for a while, the sides of the picture are a bit on the greenish side, and they aren't focused as well. You can mainly tell this when there is text, especially in the corners of the screen. I noticed the coolant for the CRTs is empty. We are getting some. Is this a symptom of the coolant being empty? Is there any procedure for refilling it, or do you just put it in and turn it on?

I know you don't want to hear this ,but it sounds like the replacement module is bad.May not have caught the problem in QA because it took awhile to show up.

Well, I wanted to update this thread.

I got the CRT coolant in the mail, so I opened the set back up and began to investigate further. As it turns out, the CRTs weren't empty. They were full, but the coolant in the blue CRT was dirty, and the CRT and lens had crud all over them on the inside. I removed the CRT and disassembled it, drained it, and cleaned out the crud. It was so nasty that the blue CRT looked yellow. I refilled it, resealed it, and reinstalled it. This made the set nice and bright again, the green haze was gone, and the images were much nicer. There was a blue ghost image next to a lot of the images on the screen now, since I disturbed the setting of the CRT. So, I got a service manual and entered the convergence mode and set the convergence. WOW! Now I have bright white instead of the faded sepia/sickly looking yellow-white I did have. The other colors are much richer and sharper, the text is crisp and in focus, and the set looks like new. In fact, I didn't know such detail and crispness was obtainable on a rear projection big screen tv. The 1080i HD really shows.

I did the coolant change and cleaning of the blue CRT only. The green showed little to no sign of crud buildup inside, and the red looked perfect. I'd suggest to anyone who is experiencing loss of color and true white on their RPTV, to change the coolant and clean the insides of the crt lens assemby(s).

Thank you craftsman_50 for helping me get the set going again! I got the set for free, the OEM remote for $20, the IC board for $191 w/shipping, the coolant for $14 w/shipping, a tube of silicone sealant for $3.50, and the service manual for $36. That's a HD 52" big screen that looks and works like new for $250! (well, $250 and a bit of work and research). It pays to DIY!

Thanks for replying back.

I usually always tell people to replace the glycol if they are opening up the unit. I had a 55" Philips and the HD picture was beautiful. It was hard convincing my wife for me to get a LCD, but I told her I would pass the projection to her father, which he now enjoys.

Thanks for posting the update, cheese. Very nicely done!

New 52-inch HDTVs are selling for upwards of $1,500. You made yourself a screamin' deal!

(Kudos to Craftsman_50, too!)

Thanks! I am happy with the deal, and even more, I am proud to have done it myself.

Yesterday I went and bought some 7ply red oak veneer plywood and some solid boards and made a unit for underneath the set to hold all my stereo equipment, Xbox, and cable box. I like the tv sitting a little higher, and needed a place to put the equipment anyway, since my old entertainment center isn't compatable with this tv. I put a rope light up behind a small trim strip just back from the top edge of the box to gently illuminate the electronics, some "moving men" sliders under it to make it easy to pull out to deal with connections in the back, and set it all in place. I spent around $110 on that including the finish stuff like stain, sandpaper, and lacquer. Now I'm done....for the moment anyway, lol.

My wife is putting in for me to cut back the dimensions of the stereo speakers now...ugh. Anyone know what the recommended air space is for a 15" 175 watt woofer? They are Sansui S-71U speakers...older but still awesome, and I haven't found a substitute for size when it comes to impressive sound, so they still sit in the living room.

The easiest way to determine proper cabinet dimensions for a woofer is to measure the existing cabinet and determine its volume in cubic feet. Also measure the port opening (if it has one) and depth of the port.

The tweeter and midrange (if it has one) aren't so picky, but if they are in separately sealed boxes in the cabinet, match those as well. Midrange and tweeters also like to be at ear level and they should physically line up with the woofer. IOW, try to keep them in the same relative positions when you build the new cabinets.

Judging by the mail I'm getting, this must be a popular thread to have come up in a search engine about this subject. Instead of answering individual messages about how I did this, I thought I'd post the procedure right here.

Let me begin by stating I am not a TV repairman, electronics expert, and I do not know if I performed the procedure the "orthodox" way, but I saw what needed to be done and figured out how to do it, and did it with success. Anyone messing around in the back of a TV set should be careful of high voltages and I'd recommend doing some more research than just this so you can do the job more safely/properly.

Here it is in a nutshell:

The repair was pretty straight forward. Go ahead and order 2 bottles of coolant and have them on hand before going into the set. Go ahead and do the green while you're in there because when I got rid of the blue haze, there was some green that wasn't noticeable/visible before. This will save some trouble because every time you remove a crt, you'll have to reset the convergence. (you'll need to access the service mode of the tv for this). It wouldn't hurt to get a service manual for your set. I got mine online in a pdf download.

Make sure the set is unplugged, open the TV, make sure the high tension leads are discharged at each individual end at each crt. Remove the board from the back of the crt and disconnect any wires, noting where they go. Remove the CRT from the set and be careful to not bump any of the control rings on the crt or things will be out of whack more than you can fix. I recommend doing only one crt at a time. Set the crt on a bench in a way that the coolant expansion chamber is pointed up. Remove the expansion chamber (be careful to not spill any coolant, it is corrosive and conductive and can ruin electronics that it comes in contact with from what I read). I used the rubber hose from the expansion chamber on the end of a marinating syringe to suck the old coolant out of the chamber. I then removed the outer lens and cleaned the crud off the crt lens. I put silicone (use 100% pure silicone) on the rubber lens seal and put it back on and filled the crt with coolant again, reinstalled the expansion chamber, and put it all back together. Then you'll have to set the convergence (start with the green and match red and blue up to the green grid). Watch to be sure the coolant does not leak onto the electronics under it. If all does well, put the back on and enjoy! Hope that helps!