Diagnose my problem - HL56A650 turning on and off

[crup]

Oh Gods of the DLP forums... please help diagnose my problem. One night my HL56A650 started turning on and off and smelled of burnt electronics (actually I thought someone was BBQing at 2am.) I think I have it figured out, but I want some untainted opinions from the helpful folks on this forum. Here is a link to video showing what happens in the back of the set... you should be able to hear the noises it makes also.

http://www.theruppels.net/images/videos ... roken.html

-crup

[ChubbsTech]

Hello crup.
I just watched your video, and that sounds like bad ballast, especially when you hear two clicks then the lamp powers, but flickers. I suggest you replace the ballast as soon as possible, because if this keeps continuing it might damage the lamp due to irregular voltage.
If you have any other questions feel free to ask.

[crup]

Nightkid,
Sweet... that's what I was guessing. I ordered a new ballast and lamp (mine is 2 years old anyway) The ballast gets in on Wednesday so I'll try that with the old lamp first. Thanks!

[crup]

Friggin A.... So... I installed the new ballast and kept using the old lamp. IT worked fine for 4-5 days but just now I smelled the same smell (the big blue cap melting) and I turned it off quickly before more damage could be done.

So... What now? Could a lamp be causing this? Or the power board? Both times this has happened have been on days where the TV has been on for 8+ hours. Maybe the fan's performance has been degraded slightly so theyre not doing their job well? I'd appreciate any advice before I dump more money on the problem!

[ChubbsTech]

Hello again crup.
It looks like there are three high possibilities, 1.- A fan is malfunctioning, and is unable to cool the ballast properly. 2.- The power supply is sending irregular voltage to the ballast. 3.- both of the above.
Here is what you can do, get a house fan, turn it on, and place it near the ballast & lamp vent. If the TV doesn’t turn off the fan is malfunctioning.
You can also check the voltage input that goes from the power supply to the ballast with a multimeter. The correct read is supposed to be 320v to 380v. if the readings are off you’ll need to replace the board.

[crup]

Ok. I'll give the fan a shot. The second ballast brd is shot... I tried it again last night and it instantly turns on and off. I'm going to try to replace the suspect capacitor first to see if I can fix it cheap... Thanks for the advice... I'll be back in a little while....

[brplut40]

I hope someone can help with this thread. I have the exact same TV with the exact same problem. It is about 2 years old as well. Instead of throwing money and trying different parts, I would like to get down to the problem. crup, did you have any resolution? I understand the bulb is older and may be worth replacing, but it turns on and lights up just fine so I do not think this is the case. I have tried putting a fan behind it and it does the exact same thing. This leads me to believe that it is not overheating, plus it is on for less than 20 seconds and all the fans are functioning. I don't think the ballast is bad, as it has enough power to ignite the bulb. This leads me to where I think I have isolated the problem, the power supply. The ballast never gets over 300 volts on the input. When the lamp is lit, it gets a constant 215 volts. this to me means the power supply is not supplying enough voltage to the ballast. I am confused with this though, as the ballast and lamp are getting enough power to ignite and stay on for approximately 20 seconds. How does a bad power supply cause the TV to turn off once everything is going? The clicks that I hear on my TV are from the power supply, not the ballast. Because the video does not have a directional mic, I cannot tell if the ballast or power supply is making the clicking noise. I get no LED lights blinking on the front for diagnostics.

Are there any other test I can perform to tell if the lamp, ballast, or power supply are bad? Should I go ahead with the power supply or try something else?

[crup]

[brplut40]

I did smell something burning when it went out. Would the ballast still be bad even if it can power the bulb on? Do you know where to get a whole new ballast? discount-merchant does not seem to carry them. I may try a power supply, because as you state, you have not 100% solved the problem. I will also check the cap that you recommended. Were you just able to un-solder and re-solder a new cap on?

[crup]

[brplut40]

Did you cap look like the picture or was it worse? Seems like it could be slightly blown. I may replace the cap and power supply to make sure it doesn't happen again. If memory serves me right, I had the power supply replaced last year when I had some problems. Maybe the replacement parts are low quality also.

[crup]

Thats exactly what mine looked like...

[Jason1976]

when i had mine apart i looked at my power supply and it had lots of bad solder joints. after resoldering them i bought a replacement cap.

[brplut40]

I replaced the cap and everything appears to be working fine. Not sure how to test the power supply, but I am going with the philosophy, "if it ain't broke, don't fix it". Amazon no longer sells those capacitors, but you can get the exact same thing from Mouser electronics at Can't beat fixing your TV for less than $10. Thanks for all the help, you guys are great and saved me a ton.

One last question, the middle fan, should it blow towards the circuit board or away? I took it off to clean it and couldn't remember which way it went on.

[crup]

Ok.. I'm back unfortunately. The replacement cap I used finally gave out. It was much more durable than the factory one though. I'm seeing the same symptoms that I mentioned in the first post again. I opened up the TV and the cap I replaced was smoking hot... and this was 5 minutes after it had already been off. It also was showing the same slight bulge with brown goop coming out. I've attached a photo.

The fan on the ballast is working fine... besides... it's not even pointing at this cap. So... I suspect something upstream is is sending too much current/voltage through the part. Does anyone have an idea of what I should check next? I measured the voltage across the cap at 207V. Thats within range of the cap minus derating... so maybe the current is too high? One other interesting note... when I used a ground on the ballast board the cap measured at 207V... when I used a ground off the ballast (screw or metal encasement) it only read at ~150V. That means that the power brd ground is quite a bit different than the ballast gnd. What do you guys think I should try next?


EDIT: After reading this whole post again, I'm beginning to think its gotta be the power board. Where would I get a new one? I can't find one in the places I usually check...

EDIT #2: Ok... I took it apart again and tried a new lamp to see if the voltage was similar. Everything looked about the same. I'm zeroing in on the fact that the ground plane of the ballast is so much different from the TV chassis gnd. 56 volts off is a little bit much :) Unless i'm missing something about the design... its gotta be the pwr board. I disconnected the power connector that goes to the ballast and measured the power output of the connector on the pwr board. The gnd was still ~55 volts off. I see a bp44-01002a on eBay I'm going to snatch up. If anyone has any insight please let me know! One FREE digital hug for someone who's willing to check the gnd plane on their ballast/power card :D

[crup]

Well... thats interesting. I installed a new power board and the measurements were different. However... not like I'd thought theyd be. Now the difference between ground on the tv chassis and ground on the ballast board is 150V. I'm not quite sure why that would be... but at least its different from my original power board. I'll report back if I see any problems. If someone else stumbles on this post having a similar problem I'd be interested in your results.....

[dlppyro]

Hi Crups!

I'm curious, how do you measure your ground plane? I'd be glad to compare notes.
where do you touch the probe to measure?

i have a HL56A650 and i think the problem is the power supply

symptoms are: when its newly plugged. i turn it on, you hear the color wheel spin up, the lamp flickers twice and dies.
then the standby (red) and lamp light (green) just blinks steadily on and on...

if you persists in trying to turn it on, it will try to for less then a second and red green blinking again.

did you ever get this symptoms?

Thanks!
CK

[dlppyro]

I figured out my problem!!!

i kept googling around for an answer and found it in a just*nswer page.

basically. my symptoms were, I turn on the TV, the lamp comes on, dies in a second. and tries again a second time and dies.
TV remains off. repeated tries to no avail. I read about the power supply and the Ballast needing replacement or the Big Capacitor but mine were all good. Then on that page. i read about the door switch or the thermostat switch might be broken.
in my case. i took out my multitester. checked the continuity of the door switch and was surprised that it was zero. :shock:
i tried several ways. i then took a paper clip, bent it so the wiring of the switch is shorted. and the TV comes on! woohoo!

I did also try replacing the power supply and did buy Japan made capacitors for the ballast. so now i have spares if in case it dies.

Thank You! Hoping sharing this helps. :D

CK

[crup]

[dlppyro]

Hi Crup!

Well after some testing, I have another problem. when the back panel was open. it lasted 30mins and could go on.
after i closed the back panel. it lasted 10 mins and started showing lines and checkering and loss of color. usually like the DMD dying. so i am going to add a fan to promote some flow. we'll see how that goes.

THanks for the Image! its a pretty good guide.

CK

[justplayin59]

Hello all. I have been reading through this and have similar problems as the rest of you. My capacitor is bulged and oozy. 1 thing i noticed no one mentioned is that when i plug my tv in it automatically starts. i disconnected the power from the ballast and the tv did not come on automatically. When my tv comes on the standby/temp light blinks green like normal then when the tv restarts the lamp light stays on red which is not in the troubleshooting image. I have already replaced the lamp and the issue remains. also with the lamp unplugged the issue remains. I am leaning towards a bad power supply. I will get my meter from work tomorrow and test. Does anyone have any new insight on this problem?

[justplayin59]

Hello all. I have been reading through this and have similar problems as the rest of you. My capacitor is bulged and oozy. 1 thing i noticed no one mentioned is that when i plug my tv in it automatically starts. i disconnected the power from the ballast and the tv did not come on automatically. When my tv comes on the standby/temp light blinks green like normal then when the tv restarts the lamp light stays on red which is not in the troubleshooting image. I have already replaced the lamp and the issue remains. also with the lamp unplugged the issue remains. I am leaning towards a bad power supply. I will get my meter from work tomorrow and test. Does anyone have any new insight on this problem?