Re: Samsung HPS4273
Same question in fewer words: Is the problem in the panel? or one of the controller boards?
jdmillard
Member
Last Activity: 07-09-2014, 08:03 PM
Joined: 03-19-2014
Location: Mesa, AZ
-
Samsung HPS4273
Manufactured in 2006. Yes, that means it's really old especially for a plasma. Here's the story:
My in-laws saw smoke coming out of the back of their ancient visa-reward-point-purchased dinosaur of a TV. They knew that I had fixed this stuff before so they gave it to me because I don't have a TV (I haven't had a TV for 6 years, because I simply don't want one).
Fixing the smoking was easy. For a few bucks, I swapped out the cap that caused the smoke then ran the TV under load for a few hours without problems. I double-checked all the solder joints on the power board...Last edited by jdmillard; 07-06-2014, 11:16 PM. -
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
Got it. Excellent.Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
Do want a lower power dissipation so it doesn't heat as much?
or
Do we want a higher power dissipation because it's rated higher and can withstand higher loads if necessary? (I'm guessing it's this one but I really don't know).Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
From what I understand: If Zener diodes are [I]regulators[/I], their goal would be to make sure that an output is a specific voltage. [B]They would be more fine-tuned with tighter tolerances because they would be [U]actively[/U] responsible for maintaining the right voltage[/B]. If TVS diodes are [I]suppressors[/I], they would aim to take care of things in case stuff gets crazy (like a psu failure or simple transient response). [B]They would not need to be exact, rather they would need to activate at an arbitrary voltage higher...Last edited by jdmillard; 03-21-2014, 07:36 PM.Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
Okay, so in my quest to find a good zener diode to replace the one that got charred to medium-well I've done some research. At first I thought that zener diodes and TVS diodes were basically the same thing but according to one source:
"TVS diodes are designed and characterized for transient voltage [I]suppression[/I], while Zener diodes are designed and specified for voltage [I]regulation[/I]."
But from what I can tell, either should get the job done for my purposes right? The charts of current...Last edited by jdmillard; 03-21-2014, 01:55 PM.Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
So my search for specific part numbers was futile. So I tried using the search options for TVS diodes. I'm not at 100% with understanding the specs so correct me if I'm wrong.
What we care about is:
-Operating voltage close to 7.5V
-Breakoff and Clamping voltages close to the ones in the pdf you sent me (under the assumption that the pdf does indeed define a component very similar to mine... which is a pretty good assumption).
-Max peak pulse surge current needs to be able to withstand at...Last edited by jdmillard; 03-21-2014, 12:24 AM.Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
Man, I tried my best to get good pics. It's tough when the only time I have available is at night (bad lighting) and the best digital camera in the house is the one in my phone. lol. You did great with them.
I'm looking into those part numbers of the voltage suppressors. Digikey and Mouser are both out of stock. Any suggestions? I could search their inventory for products of the same dimensions and specs...Last edited by jdmillard; 03-20-2014, 11:41 PM.Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
Success! I plugged it all in, fired it all up, added it as an extended screen to my laptop and it performed flawlessly.
Bud - If you didn't live 11 hours away, I'd buy you lunch my friend. You are an excellent troubleshooter and you explain things well. This has been a great experience for me. The monitor is outdated, but the things I learned certainly are not!Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
I'm getting a constant 5V. But that is without a load. I'm gonna plug the rest in and see how it goes.Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
So I test to rule out any other component failures. If everything looks good, then I'm clear to order and replace the necessary diode and put everything back together. Right?Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
So what is the worst-case-scenario if I just leave it (the Zener diode) out?Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
Well well. I just tested and got 7.66V. I come back to refresh page and you're two steps ahead of me. So does the 75B have anything to do with the 7.5? or was that just a coincidence?
EDIT: Also, it fell apart when I took it off the board. I didn't even pull very hard. That thing really was dead. And the click only happened one time (I'm guessing you expected that that).Last edited by jdmillard; 03-20-2014, 10:22 PM.Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
Sorry to flood you with pictures, I'm trying to get you some better lighting. I adjusted some things and snapped a bunch more. There's some glare, but it's on another part of the board.
EDIT: Nevermind
...
Last edited by jdmillard; 03-20-2014, 09:58 PM.Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
It's just a bridge (I guess you say the technical term is a jumper wire). The two spots below it are full components, but the one you circled is just a jumper. It jumps directly to the right ("due East")...Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
I have no issue with swapping out the burnt diode. And since I'll already be paying shipping (the majority of the cost), I can swap out the startup cap and those 2 transistors I already pulled out just for good measure.
I'm wondering if there will still be overvoltage or some other problem that will just burn it out again. Would it be possible to get another diode with better specs? or will that just cause problems?Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
So what caused it to burn? Was it the endless "mileage" on worn out caps? Or was it simply just too old to carry on and would have had a super nova regardless of the other parts?Last edited by jdmillard; 03-20-2014, 09:30 PM.Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
Here is a question:
What is that black thing? (more detail in the image)
EDIT: the resistance across it is zero. I don't know if that is significant, but there you go.
EDIT: there are 2 similar-looking ones on the other side of the board. I don't know if they do the same thing, but they both had solid resistance across them.
The number printed on it is impossible to see in the image, but it's
[B]75B[/B]
[B]46[/B] (the six may be an 8 or a B... difficult to tell. doubt it's a...Last edited by jdmillard; 03-20-2014, 09:26 PM.Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
Here is a better view of the burn. I was having trouble getting a crisp image of the back without getting glare from the flash. I even went to a different room with better lighting and tried without the flash. So i just uploaded a bunch of them. The corner that is shown is the "top-right" corner. So I flipped the board as though it were a page from a book. The burn mark would be right below where you see the IN, OUT, ADJ
EDIT: In the first image, is that thing to the left of the voltage regulator supposed...Last edited by jdmillard; 03-20-2014, 09:07 PM.Leave a comment:
-
Re: HP Pavilion vf15 (15" Flat Panel LCD Monitor)
Nope. I got it from my parents a long time ago and I seriously doubt that they would ever have it worked on... ever. They would just buy a new one.Leave a comment:
No activity results to display
Leave a comment: