Re: Samsung LN32B530P7F PSU issue
Sorry, had a couple late nights at work.
I measured from the positive side of CM881 and CM876 to the negative side of CM867 and got 1.2VDC both times.
0VDC from CM852 (pos) to CM867 (neg).
I suppose this means I should be looking at the hot side?
b4ndit
Member
Last Activity: 06-11-2014, 09:11 PM
Joined: 05-31-2014
Location: Florence, KY
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Last edited by b4ndit; 06-11-2014, 09:11 PM. -
Re: Samsung LN32B530P7F PSU issue
Thanks for your help OldTecho. I'll do some more diagnosing after work today.
I plan to check the voltages at the points you mentioned and also double check the capacitors and diodes to make sure I didn't miss anything the first time.Leave a comment:
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Re: Samsung LN32B530P7F PSU issue
Just swapped out CM808, the IC, and the two zener diodes with the new parts.
Didn't get any magic smoke or anything, but the TV still does not work. The symptoms have not changed at all, so I believe the problem is somewhere else on the PSU.
I have no idea where to look right now as I've tested most of the major components on the board and can't find anything wrong.Leave a comment:
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Re: Samsung LN32B530P7F PSU issue
OldTecho, I know my problem is the PSU because I don't even have standby voltage.
I ordered all the parts last week and the last of the parts were delivered Friday. I am planning on performing the repair today.
I ended up purchasing three zener diodes (one is a spare), two IC's (one is a spare), and enough capacitors to recap the PSU to make the shipping costs worthwhile (added one spare of each kind, filter cap not being swapped). For all these parts, I ended up spending around $22.
I plan on swapping out...Leave a comment:
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Re: Samsung LN32B530P7F PSU issue
Ok, I have another question. The capacitor CM808 on the PSU is a SamYoung 50V 22uF. However, in the schematic it says it's a 50V 47uF. I'm leaning toward trusting the rating on the cap in the PSU, but I thought I'd ask to be sure.Leave a comment:
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Re: Samsung LN32B530P7F PSU issue
Good catch, I almost forgot about CM808.Leave a comment:
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Re: Samsung LN32B530P7F PSU issue
Thanks for all your help. I'll look at the different offerings from B+K and Fluke to see if I find a good meter I want to buy.
My plan is to order that IC (I'll probably get two, just in case) and those two zener diodes (also will probably buy a couple extra) sometime today. I started looking around the web last night and it seems that digikey only sells the IC in bulk. So it looks like my best bet is ebay.Leave a comment:
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Re: Samsung LN32B530P7F PSU issue
In my previous post, I posed the question of whether a reading of 241 is OK. I watched a few youtube videos on how to test different components and it seems that the reading I got is perfectly fine.
I've been testing different components on the board and I haven't found anything wrong yet. I retested each of the diodes (mostly for practice and to get used to this cheap meter) and they all seem fine. I checked continuity on the TM801S transformer and everything checked out fine as per the schematic. I'll keep testing things as I think...Leave a comment:
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Re: Samsung LN32B530P7F PSU issue
Unfortunately, the Fluke 114 does not have a diode test mode. It's not a multimeter made for electronics, but it has worked well for what I've used it for in the past. However, I may be in the market for one that's made specific for electronics. Would you have any multimeter recommendations?
I retested DM802 and DM803. They both show OL and -OL. However, when I put the meter into audible continuity mode, it briefly beeps when I switch the leads on the meter back and forth on the leads of the diode. Because of this and the fact that...Leave a comment:
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Re: Samsung LN32B530P7F PSU issue
I had to Google how to measure the three prong diodes as I have never done it before and didn't know how to check it. I learned that the important bit is to measure from the center pin to the outside pins to ensure they don't have a short. I also measured the outside pins just to be thorough.
DM857 - Measured 18 M ohms with positive center and outside ground. -0.7 M ohms with ground center, positive outside. Outside to outside measured 0 ohms, but this should be OK (if I understand everything correctly).
DM852 - Meter registered...Last edited by b4ndit; 06-01-2014, 05:47 PM.Leave a comment:
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Re: Samsung LN32B530P7F PSU issue
ZD803 and ZD804 both register 2.5 M ohms in one direction and OL (none) in the other. I would assume this would be fine (not a short).
I assumes this means I should look to replace UM801S and CM808, correct?Leave a comment:
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Re: Samsung LN32B530P7F PSU issue
The fuse FM802S measures 0 ohms when I take it out and check continuity, so it seems fine to me. I also checked voltage from both sides of the fuse to the negative lead on the filter cap and it read 167VDC both times. If you know of a better way to test it, let me know.
CM808 measures between a range of 9 and 15 VDC. It seems to fluctuate pretty rapidly.
CM804 measures about 0.6 VDC.Leave a comment:
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Re: Samsung LN32B530P7F PSU issue
I'm showing 168VDC on the yellow filter cap. Hitting the power button on the side of the TV does not seem to do anything and I still measure 168V on the filter cap.
When I've searched for similar problems, it seems that most of the time they indicate that their TV's red power LED is lit in some fashion. That is not the case here as the red LED is completely off.
EDIT: I checked the ribbon cable connecting from the PSU to the main TV circuit board. I used the GND at the far end of the ribbon cable (opposite of the power...Last edited by b4ndit; 06-01-2014, 10:53 AM.Leave a comment:
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Samsung LN32B530P7F PSU issue
A coworker gave me a Samsung LN32B530P7F television for free because it would not power on. I suspected bad caps, but they all appear fine and none of them were shorted when I checked their continuity. I looked over the entire PSU and could not find any obvious problems.
[B]Symptoms: No power on, no lights, no noise, nothing.[/B]
I got out my Fluke 114 multimeter and tried to help trace down the problem. I grounded the meter to one of the screws on the border of the PSU board (LUG4). I then used the other lead to check the AC side of the board. I'm showing ~67.5 volts... -
Re: New Members - please post your introductions here
I am a college student that enjoys tinkering with computers, networking, and occasionally electronics. I realized that my electronics skills were lacking, so I decided to join the forum in the hopes of learning something new and maybe fixing some broken electronics along the way.Leave a comment:
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