I recently replaced the convergence IC's in my 51MP392H/17, clearly marked all ribbon cables and wires before disassembly. Now, after replacement, TV will try to power (no picture), and turn itself back off with a "blurp" from speaker. Then will try to start again, only to turn off again about every 15 seconds, with no picture, and cycle that wait continuously, never powering up. Unit did work (despite convergence issue) before removing board. I checked resisters and all give same reading and seem to be fine. I even desoldered, and resoldered in the old IC's, only to have the same problem. Any help would be grealty appreciated! Thanks, -Drew
check for open circuit protectors in power supply or fuses.look for open resistors as well
I have checked continuity between all resistors and found none bad or open. Is there another way to test them? Also, fuses on power board are all okay too. I just dont get it, it did work before, despite convergence problem. I even put old one back in...???
if you got replacment ics that are cheap they sometimes are no good right from the start. if they were no good they can cause damage to power supply. im assuming the ics are stk-392-110 check for pico fuses they look like resistors. you may have to lift one leg to check them. also if this set has ssb take out and reset it in socket. this bd. stands vertical.
I did get Ic's that are cheap, $6.99 each. They are STK392-120's. Where would I find those pico fuses? Why do I need to lift one leg to check the resistors, and what are you refereing to as "ssb", and "bd"? Sorry for the exhaustive questions, I really do appreciate your help.
you dont have to lift the resistors you might have to lift one leg on the pico fuses.the ssb is the small signal bd.if your set has one it will stand vertical small bd rectangular towards the back of the set.sometimes when you change the ics it may come loose.if your tv dosent have this bd. then thats not the problem.also did you hear a pop when you turned it on after replacing the ics.you should replace the ics with stk392-180 same ics but stronger verison.the pico fuses should be found on the large signal panel as well as around the ics.
also is the power light on the front of the set blinking. if it is count the blinks.
Okay, I dont recognize the item you are describing, however, I took some photos that perhaps can help you help me ;-) My power light does not blink when attempting to turn on, it clicks and acts as if it is powering up, emits that hiss noise like old tv tubes do , and then just "blurps" and sound from the speakers and shuts off after about 5 sec.. Stays off for around 5 seconds, then tries to power itself back up again and if I do nothing, it will just cycle that way on and off till I unplug it. I have only let it do that 5-6 times by itself and just realized it wasnt going to happen.
This is the pic of my board after soldering in the new ICS...
I checked continuity on all of these resistors and all are good......
And here is a pic of the board re-installed, along with the other two board in the set, minus a couple inches of the board on the right which is where the power comes in.
I really appreciate the help here, if a new pic or pic from different angle will help, let know. Thnaks a bunch for taking a look!! -Drew
Also, what I meant by "hiss", is that normal noise that a tubed tv makes when starting, nothing abnormal sounding.
Forgot to mention a reply to your question, heard no popping or anything abnormal sounding when I powered up first time, nothing different than what its doing now. Also, this might be worth mentioning, if I turn off with remote when the set is trying to start for that 5 sec, it will show snow on the screen for about 3 sec and then go blank. However, that is the only time it will show anything on the screen, and will only do that if I power off with remote, I cant get it to do that if I hit the power button on the set itself.
thanks for the pics. ive worked on many of these type sets. the small signal bd. is directy behind the tuner. i know when these sets act the way you are describing this can be your problem. if you disturbed the socket conn. it may not be seated properly.if you lift the plastic bracket that holds it in place push it to the right of the set and then lift out then reset it in. this bd is basiclly the brains of the set controlling logic functions.if set still acts up then all i can say is make sure you did not bridge any conn. when you solderd. also the fuses in this set are black and round and they have there value stamped on top. to check them you have to get to the bottom side of bd. check them on the power supply/sweep bd.as well. thats the big bd to the right of the bd. you replaced the ics on. the small signal bd. is inside metal case supported by plastic bracket. be carefull removing it...
couple more things. make sure you did not crack the bd. when you took it out also double check all connectors you undid when you took bd out. this chassis has a tremoundous amount of connectors. i know you said you marked them just recheck them. if set still does not come on re replace convergence ics. but replace them with stk 392-180. you can get a good set of these at www.tritronics .com i belive there about $15.00 each.
I really do appreciate the help! However, I still cannot seem to get this freakin' set to do anything. I oredered new IC's from the site you recommended and will see if that remedies the issue. I just cant think of what else it could be. I'll check back in a few days and give an update to let you know how it goes. Perhaps the cheap chips are the problem, thats all I can figure for now. If after replacing the IC's it still does not power up, its probably off to the repairman. After all, the set was free in the first place. Thanks again, I will check back to update.
*UPDATE*
Received new original Sanyo IC's yesterday, put them in, and set fired right up without a problem. I hope this thread reachs anyone who, in the future, attempts this repair on thier own. USE ORIGINAL PARTS on this set!!! Cheap knock offs will not only cost you more in the long run, but give you a headache you'll never forget.
Good luck to all and thanks again to the excellent help that I received here at Techlore ;-)
-Drew
Dear meggabad:
I have exactly the same symptoms with my 51mp392H/17 as you described. They started when I turned off the TV and tried to turn it on very quickly again...( about the time I Hit the power button to turn off, I heard something interesting and tried to turn it back on) That's when the problem started. Just like you described, the only way to shut it off is to pull the plug, the TV keeps trying to restart then shuts down and tries to restart immeadieatly.
OK: I'm not an electrical Engineer, (Industrial Engineer) or a electronics wizard: From what you described I think you have solved my problem. If you think this repair might be easy enough to tackle on my own, I would appreciate if you could describe what needs to be done such that a novice might have a chance...Otherwise,,if you think attempting the repair might lead to more frustration and cost than it is worth, I would appreciate that insight as well... so you might just say..."Your in over your head, call the repair man" And I guess that's what I'll do...
Thanks for any insight
Jeff
Your set has the Philips 300 series chassis. The service and training manuals are in the Techlore Resources download section, but start by searching Techlore Articles for "tv safety" and reading those articles.
Common faults can be bad solder joints, the convergence ic's and their related resistors. You will need a magnifying loupe, a multimeter, and soldering supplies to get started.
If you do replace convergence ic's heed the warnings to use Sanyo brand chips and use heat sink compound.
also see this whole thread:
http://www.techlore.com/forum/thread/16736/Magnavox-51MP392H-17-51-quot-...
and see this link on replacing convergence ic's for the same chassis:
http://www.techghetto.com/tv-repair/
I had somewhat of the same problem, I had a bad portion of the board where I had to build a new copper routing with circuit wire, the copper burned off when the resistor failed, you may need to do a little Frankenstein work on your board as a last resort... remember use a low 15 watt soldering pencil, use leaded solder, and USE flux!
HOWEVER:
I expect you have a "cold solder point" thatÂ’s where the solder and the board didnÂ’t fuse, cleaning off the solder with a de-solder wick then USE FLUX, and heat the board then touch the solder to the point should take 3 secs, make sure the iron is good and hot, plug it in relax and be patient...
Good luck, I attached some reference below
51MP392H/17
Actually I have this TV and you need 2 Convergence IC's STK392-120's (120's and 150's will work) of course order 2 of the same type I'm using replacement 150's they allow for a little higher heat and were cheaper ALSO you need to replace the 12 resistors with 6.8 ohm metal film resistors, make sure they are metal film! donÂ’t skimp out here I did and then they blew and fried my IC's and I had to replace everything again!
Great reference link that I posted pictures on, check out page 3
http://www.techlore.com/forum/thread/16736/Magnavox-51MP392H-17-51-quot-...
Where I got all my parts that worked:
Suburban Electronics http://www.suburban-elect.com/
Manual Library you should find all you need here:
http://www.techlore.com/group/2/list_downloads
What you need:
(2) STK392-120 OR STK392-150 IC chips
(12) 6.8 Ohm Metal Film resistors
set of star screw drivers
15 watt pencil solder pencil, DO NOT use a high watt iron you will fry the surface mounted item.
good leaded solder, and flux
BTW if you donÂ’t plan on trying this and are going to throw out the TV, I still need a IC convergence board for a 51MP392H/17 TV I'm fixing, I'm willing to pay S/H and buy your IC board thatÂ’s not been tampered with. [email protected]
If anyone is interested, I am parting out a 51MP392H/17... I have a complete and tested "convergence" board with BRAND NEW Sanyo 392-120's in it.
I also have the main power supply board, all 3 CRT's, the fresnel screen, button panel, the screen frame, and the the mirror.
I do have the fresnel screen as well, but it has a small 1.5 inch crack in the center - not noticable when the tv is on, just not the greatest cosmetically.
I have Tested both the power supply and convergence board in a working unit and they function perfectly.
If you need parts, email me at [email protected] and we can set something up.
If anyone is interested, I am parting out a 51MP392H/17... I have a complete and tested "convergence" board with BRAND NEW Sanyo 392-120's in it.
I also have the main power supply board, all 3 CRT's, the fresnel screen, button panel, the screen frame, and the the mirror.
I do have the fresnel screen as well, but it has a small 1.5 inch crack in the center - not noticable when the tv is on, just not the greatest cosmetically.
I have Tested both the power supply and convergence board in a working unit and they function perfectly.
If you need parts, email me at [email protected] and we can set something up.
Anybody have an HV board, I am told that the flyback transformer is dead. The tv will not turn on and only chips (coming from the back left of the tv. Any help would be great I am trying to fix this for my parents. Please let me know how much for the board and shipping.
Thanks
I have a parts Philips Magnavox 51MP392H TV, everything is working I used the convergence board from it but have all the other parts including the remote. if you send me pictures of what you need we can work somthing out... I got to much spam before so I dont post my Email, however you can contact me thru my website at www.CFISTORE.com just go to the contact me section and write me an email it will automatically send the message. I'll reply and you'll be able to attach pictures to my reply...
Just want to say thanks to everyone that contributed to this thread. A few months ago I did this repair on a 51MP392H/17 for the convergence problem. Replacing both IC's with genuine Sanyo IC's. The repair seemed to work. I tested the unit before putting the back cover on and it worked fine. Then put the back cover on and secured all the screws. When I plugged in the unit I heard a pop and then no power. I believe the front power button flashed but I didn't note the how many flashes. I took the cover back off and reseated all the connections to the board. The system worked again. I put the back cover back on and the system continued to work. Well it seamed to work fine for about 2 months. now if the system is left unplugged from AC and then plugged in and turned on it will work for about 5-10 min. Then it powers turns off and you hear some noise from the audio circuit. Then the system will turn back on by it self and you get picture for about 10 seconds and then the cycle repeats until you pull the plug. Anybody have a suggestion where to start troubleshooting? Or seen this issue before after a repair? The next time I go into the set I will try re seating the connections again to see if that helps but I thought I would ask the pro's. Thanks in advance for your help
my power light is flashing 9 times what does this mean I just replace the ic"s and now it will not come on it clicks like it i s coming on but nothing happens and then turns off light starts flashing, I need help on this!!!!!!!!!!!!!!!
I just came home and powered up my set, heard a second click as it powered up and now I dont have a picture. I have sound through my stereo but no hint of picture. I also have a high pitched chirp at half second intervals coming from the main power supply?? Any help would be greatly appreciated. checked both fuses good.
I have a Magnavox 51” rear projection TV. Model number 51MP392H/17. I have recently preformed a coolant change on all three CRT’s. Things went real well with that. No leaks and reel clean. The set also had a convergence problem. I replaced the convergence IC’s Sanyo STK-120’s and all 12 of the 6.8ohm resistors in the circuit. I made sure to replace the IC’s with original Sanyo IC’s.
I reassembled and powered the set up. The red power button would light up, it sounded like the set was going to turn on then it would turn it self off with a popping sound coming from the speakers. This cycle would continue until set was unplugged. I could not get it to stop other wise. There was never any picture or audio during this.
I took the back off again and removed the convergence/input board again. I double check for any kind of shorts around the STK ICÂ’s and resistors I had replaced. As this problem seemed to me like a short of some kind turning the set on and off. All looked fine. I reassembled and reseated all connectors and plug in boards to the main board. I did not button up completely before turning the set back on.
When I did power it up this time the set seem to slowly come back to life. First the audio came back then the blue CRT then the green CRT then red. So what I thought was when I first reassembled the entire set I applied fresh silicone to secure the circuit boards that plug onto the bottom of the CRTÂ’s. I had to remove the original silicone to remove the CRTÂ’s to clean and refill the coolant. So what I thought was the silicone was still wet and it actually looked like some had dripped down on the board and maybe shorted out the board. So I figured when the silicone finally set up the short went away and the set started working. So I was a happy camper. I total reassembled the set. I took great care to take a lot of pictures when I disassembled it to make sure to get everything back the way it was. Paying close attention to all the wiring to make sure it was tied up and out of the way of anything hot. Again I referred to my pre disassembly pictures for this. So trust me this set went back together the way it came apart.
When I was done I fired it up preformed a factory reset on the convergence and preformed a manual convergence in the user mode. Things looked great. The set looked like new. I moved it in my bedroom hooked up all my electronics to it. DVD, DVR things like that. The set worked great for 4 days. Just today my girlfriend went to turn it on and itÂ’s back to the on off thing. It will try to start up the red light comes on then it turns of with a popping sound from the speakers. Very frustrating. Do you have any idea what this could be? I am going home in a few mins to try and reseat the plug in boards again on the convergence/input board but I am not very confident this will work for me again. Please help! I have spent a lot of time on this set and I am just about done.
Thanks in advance!
I had a very similar problem. Except the set worked for a few weeks. then it would work few a few hours at a time and then go out. What fixed it was one by one reseating all the connections. I think the one connection that really did it was the HD Component board (probably not the right name, but the board that you plug dvd players into for Higher definition). Actually I would try with that board first. Just take off the back reseat the HD Board. and then try to fire it up.
Hey HightowerFL.
First off thanks so much for taking the time to reply to my post. Like I said yesterday I left work early to go home to work on the beast again. LOL It was real frustrating that it stopped working again. Anyway when I got home I took the back off, reseated the boards I mentioned and the one you are talking about. I also reseated the thin ribbon cable that comes off the HD module and plugs into the main board. I hope you can figure out the one I am talking about.
I button it back up and it fired right up again. So I am back in business. Do you have any idea why this would be? This is the same thing I did the first time I put it back together. Maybe itÂ’s a cracked solder pad on one of the plug in board connectors or something. Not sure but I hope it keeps working.
There was another thing I noticed before I put it back together all the way and maybe you could help me with. I notice a slight accessional crackling static noise coming from the fly-back(HV) transformer. Did not smell anything or see any sparks at all. It was very slight and sort of went away after a little bit. I could hear it every once in awhile when I turned everything down sound wise and listened real hard after I got everything back together and pushed back against the wall. I checked on it a couple of times. Could this be dangerous? Is this maybe why the TV was turning itself off? Could the fly-back transformer be going bad? Let me know if you have any insight on this. Other then that it seems to be working fine and I ran it all night long last night. I have a bad habit sleeping with the TV on. I canÂ’t sleep with out it. LOL
Thanks again!
Billman09
Why it happens? No idea. I did the convergence repair and when I first put it together ... POP! but didn't see any burn mark. Reseated everything and it worked the second time around. My experience w/ flyback transformers is usually they squeal or whine or are high pitched. They don't usually sound staticy or crackly. But I suppose anything is possible. My electronics experience is mostly in computers with a few DIY projects here and there. The static or crackle noise might be from one of the many ground wires not being fully grounded and there is some sort of static build up that isn't getting dissipated (I'm speculating)
Hightowerfl
Well Again HightowerFL thanks for your reply and input. I just did a little reading on flyback transformers. They claim that when they start to fail they start arching between the windings internally. Maybe this is what I am hearing. Debatably this is caused by dirt or dust build up over time. And let me tell you when I first started working on this set it was real dirty and dusty inside. So I would not be surprised if this did have something to do with it. I have everything cleaned up real nice right now but it was like that for awhile. What I donÂ’t understand is when I first got it back together I did not hear this sound. I might go back into it over the weekend and double check the wiring and make sure there is not a ground wire disconnected like you suggested.
It ran just fine yesterday and over night and I did not hear anything from the back so maybe it burned off some dust or something. I will double check it tonight to see if I hear anything.
It sounds like if it does fail it will take out a low voltage input transistor and or some fuses in the input power supply to the flyback. So I think it will just shut down if the flyback fails completely. So I might be in for another repair on this set in the future possibly the very near future. LOL I will just run it till it quits I guess. I have it on a serge protector as well so I would think it is pretty safe for now. If you have a difference of opinion by all means let me know. I do worry about the safety factor with this.
Oh well I love this set and as long as I can keep it going my self and not have to pay outrageous service chargers I will.
Take care HightowerFL
Billman09
Im having close to the same problem. I replaced the ICs a few months back, got rid of the convergence issue and the tv and picture are fantastic thanks to all the help i got here. But now i noticed that when i turn on the TV, it turns right back off and then back on again... really quickly...like maybe just a second or two delay. Thats not really a big deal, but every once and awhile(every few hours), a message pops up and says TV is shutting down in 60 Seconds or something to that effect. I dont even have the time set on the TV, let alone the sleep timer, so its definitely isnt the sleep timer (being set). I played around in the service menus, so maybe i set something wrong it there? i played with the setting "I am Alive" or something, but i set it back to the default, Off. Ill check error codes if there is any, but i was seeing if anyone here had any clue to this problem. Thanks!
*edit*
It would almost have to be a setting in the hidden menus, because i didnt have any of these power problems a few days ago, but i just couldnt leave well enough alone with it being fixed, so i messed with the service menus. opppps...
juggalofr33k,
Your problem sounds very similar to the one I had about a year or so ago. Did the IC repair, 2 months later turns off after about 15 min of use. Here's what fixed it. I opened the back of the unit and reseated every connection that I had to remove to do the repair. I don't know this for a fact but I believe that reseating the HD board (the one with the component connectors, not the composite connectors)is what did the trick. I think I read that from someone here in an earlier post. I don't know if your tv has been moved recently or if the tv has gotten bumped recently but my issue started after the tv got rolled across a tile floor. Since then the tv has actually been moved to a new house and it has worked fine. Either way, reseat all the the connections especially the HD board. Actually try just the HD board first, and then test it before putting it back together. It should only take a few min. I hope the reseat works for you.
HightowerFL
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