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Samsung HLT-5687 still cycling on/off at power-up, AFTER both power supplies replaced

3K views 6 replies 4 participants last post by  ea7 
#1 · (Edited)
If anyone here can help shed some light on the following problem, I’d be very grateful.


I have a 56-inch Samsung DLP model HLT-5687, and recently it began exhibiting a symptom where after turning it on, it would immediately "click" off and then on again, and do that numerous times before finally deciding to stay on for good. When the problem first began it would power cycle like this this once or twice, but now it’s up to a dozen or more times before it settles down.


Reports of this sort of power cycling problem are strewn all over the Internet, and my research indicated that my symptoms were most likely due to the well-known “defective capacitors on the power supply” issue—the same one Samsung used to provide free repairs for under that class-action settlement several years ago. I never had any repairs done under that settlement, because I wasn’t having any problems with my set at the time.


Now that I am having problems, Samsung is of course no longer offering to repair the issue for free, so I decided to try and fix it myself. I opened up the TV and noticed that what Samsung calls the sub-power assembly (part # BP96-01726A) had numerous leaky capacitors.Thinking this was the culprit I bought a replacement part online and installed it, only to find that it had absolutely no effect on the problem.


I had also looked at the set’s main power supply (part # BP44-01001C) which didn’t have any visible capacitor leakage, but since replacing the sub-power board didn’t fix the problem I thought maybe the main supply had some non-visible issues and replacing it would do the trick. Well, I replaced it, and it didn’t fix the problem either.

After wasting more than $120 on two different power supplies, I’m at my wits end here and at a loss as to what is making this DLP cycle on and off every time I turn it on. Actually it’s not quite EVERY time—if I turn it off and then on again a few seconds or evenminutes later it starts up without any problem, but if it’s been off for a few hours it exhibits the cycling problem every single time. I should also mention that once it finally turns on, it stays on, indefinitely without any problems. Since the issue only occurs when the set is "cold" it doesn't seem to have anything to do with heat building up (and in any event, I've verified that the fan is working).

Long story short, I can’t afford to do any more speculative repairs, but it seems like only a matter of time before the problem gets so bad that the TV won’t turn on anymore.

Does anyone have any idea as to what is causing my problem and how it can be fixed?


Thanks very much.


Joe
 
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#2 · (Edited)
Right there with you Moran. My HLT6187 SX/XAA just did the same thing, and officially died last night. Not that it matters now but I actually was able to get my ballast swapped out about a year ago under the lawsuit and I also had them replace the dlp chip because it was dropping pixels. So I feel "vested" in my unit.

I was able to play the power on game where it would blink green light 10-13 times and the go back to standby and if I pulled the plug and plugged it back in, the screen would then come on and as long as I left it on, no issues. Sometimes it would come on and then the screen would lock up, either as a still image or pixel "art" tearing images frozen, but then flicker and then come on normal. Getting progressively longer week to week to power on and now it cycles 10 green flashes and then back to standby.

The only thing I narrow down in posts here and there is the next logical thing to challenge is the LED board. apparently the symptoms we have could also be due to that board being bad or if we are lucky just one of the LED's. Once I get home tonight, I am going to do a DC volt check on the 3 LED's plugs (right where they plug in to the chassis.) I have heard that they should read around .5 for each and if one is bad it will read +10v etc... if they are all even, I guess I might assume its the LED board itself but don't hold me to that. (I'm looking for more steps to prove or challenge testing the board). I'm just hoping that one of the LED's shows its face when I get home to check it. if they all read 0 or even, I'm not quite ready to blame the whole board till I read a bit more on that.

I noticed you posted this about a month ago, any news or update on your end, or is the tv in a landfill by now? :)

Just curious if you tried reading volts on the 3 LED's ?
 
#3 ·
Hi and thanks for your reply.


My 5687 is still functioning, though it's now up to close to two dozen power cycles before it will stay on. Seriously, it takes almost 5 minutes from the time I power up until I can actually watch something.


Unfortunately I haven't done anything new or researched any further since my original post-- I just haven't had the time to fight with it, and frankly I'm a bit disgusted with the whole situation. After all the time and money I wasted replacing the two power supplies, I'm not going to try any more speculative repairs unless I can determine with certainty that the problem is part x that will cost amount y. Between the power supplies and the DLP chip which I replaced myself about 18 months ago, I'm already in for $400+ on this barely six-year-old set that I paid $1500 for. As much as I'd like to keep it running, the economics of the situation dictate that I will most likely just go out and get a brand-new smart 60-inch LED from Costco for $800 the day this set dies for good.


One thing I can say with certainty is that I will not buy another Samsung.


So did your LED voltage angle pan out and were you able to coax your set back to life? And just out of curiosity, about how long was it from the time the symptom started until your set went kaput? It's been a little over 3 months for me, and I'm just wondering how much longer I likely have...


Joe
 
#4 ·
I hear you.. But after my trip to best buy last night. My fire to get my dlp working was re-kindled. Nothing short of 4k hold a candle to our set. And if I need to replace the DMD and main board for $ 300-400 I just might. My only concern reading around is that the fault with the design of the main pwr board was a crossback voltage issue on or where AC is converted to DC. I wonder if the replacement main power board u have has Addressed that. In had chip and sub power board replaced on mine. I figure if I say #$%@# it and buy the main (processing) board and then the DMD . its worth it unless the voltage faults of the main power board are guilty of failures. That is my only holdup. So long story short.. My voltages on the DMD to the LEDs seem to pass fine. 2-3volts across wire and 14-16volts to chassis.
The way your TV is auto trying to fire again sounds like a short in a safety system which is a bit different than my issue . aka when I unplugged one of the led lights or one of the fans.. It cycled off and back on the way u describe.
 
#6 ·
I have/had the same TV. Not sure if you're still at it or have given up, but I had a similar issue, if not the same. Around the same time last year too, except my TV just died one night. I've never let it try to boot up for 5 minutes though. I also used a volt meter to check each LED. The red LED didn't register correctly. I connected the green (or blue) LED power cables to the red and it still didn't register correctly. Which is why I think it's some safely thing that's kicking in, to keep the red from over-heating.

For some good info on troubleshooting such an issue, Google "justanswer hl-67a750 quit" and click the first link. This guy swapped out almost everything. In the end, it might have been a post-back wire. I never got around to checking this on my TV though since the model is different.

Even after reading that the most common issue is 1) LED power board or 2) red LED, I didn't want replace anything without a positive way to determine what was at fault. Maybe this info will help. It sure helped my understanding.

The TV is still in my basement. Not ready to let it go.
 
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