Re: Need help troubleshooting a sylvania LC420SS8 power supply
Was there any success with the troubleshooting?
Was there any success with the troubleshooting?
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Re: Need help troubleshooting a sylvania LC420SS8 power supply
It was short smt and tht diodes with mine... replaced - works like charm!Comment
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Re: Need help troubleshooting a sylvania LC420SS8 power supply
I need help with my sylvania LC420SS8 lcd tv and the problem I am having is that everytime that i turn the tv on the green power light just blinks for bout 10-15 seconds than goes back to standby to the red light? I have been looking all over the web for now 2-3 days and so far i think it is maybe the F501 fuse or resistor or something but ant quite sure why it's not powering up . I hope y'all can help me with this and if i been to i can take some pictures of the power boards and everything and post them on here so everyone can see it.Comment
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Re: Need help troubleshooting a sylvania LC420SS8 power supply
Hi, I am trying to repair one of these TV's, and was hoping someone could point me in the right direction to finding the fault on the board. I notice OP never said whether he fixed this TV or not, not encouraging...
When I got the TV, it was filthy inside - cleaned all that. Found that the main fuse was blown. Replaced it with the proper type of fuse. When I plugged in the TV, the lights in the room dimmed for a moment, which tells me that the slow blow fuse as doing it's job and not blowing right away, yet, there must be a dead short somewhere on the board; because the fuse blew again.
I'm trying to figure out what I should test on the board to find what's shorted, because nothing shows visible damage like I had hoped.
Thanks in advance!Comment
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Re: Need help troubleshooting a sylvania LC420SS8 power supply
Its alot cheaper and less time to just order a new board for 20 to 40 bucksComment
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Re: Need help troubleshooting a sylvania LC420SS8 power supply
Done. Found a used board for $38 shipped on eBay. If the replacement board fails as well in the future (seems likely given the design), then I have a board to scavenge for parts.
It seems like the first thing to check is all the large diodes around the transformer.Comment
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Re: Need help troubleshooting a sylvania LC420SS8 power supply
Two components on my old board are scorched, BC508 and BC509. Schematic has them labeled "Bead". What actually are these components? I can't read any markings on them.Comment
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Re: Need help troubleshooting a sylvania LC420SS8 power supply
It is highly unlikely it's going to be smt or tht or any such BS as that. The technology on this set is VERY antiquated and HARD to obtain. I had to get an ic for this set from Japan, and it took 3 tries...they kept sending the same part, in a smaller "package".
I detest someone trying to use abbreviations for technology they don't understand. If you narrow it down to a board, it's much easier and cheaper to replace the board itself.
....or get at least a newer model to work on. For this one, you need a scope, a good dc power supply with a variac and an ac supply with an amp meter, an isolation transformer and a variac to adjust up or down the operating voltage to keep from destroying parts and getting electrocuted.
.....JMHO
Joe
Joe's TV and ElectronicsLast edited by geronimoejoe; 09-29-2017, 03:18 PM.Comment
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I have wanting to do this project for quite sometime now and I finally found a switching power supply that will work on this desoldering gun station ZD-915 that the original switching power supply took a shit and just was not worth trying to fix it because this switching power is not quite big enough to handle the heater element and the vacuum pump
One note when I tested the switching power supply and the voltage control board I noticed that this desoldering gun heat up much faster than the original switching power supply which I was really surprised by to the point that I might buy... -
Hi all, I just need to know that, can i use SMPS type power supply to test and short circuit detection on a laptop motherboard?
I saw 95% of repair guys are using only Linear bench power supply. linear bench power supply is pricy, thats why i planned to get one SMPS supply.
i know that in linear power supply the noise will be very low comparing to SMPS supply.... -
Hi, this is for troubleshooting and, hopefully, repairing a Delta Power psu
that is still quite new, as it worked OK for some months until it failed.
At the time I was not into power supply electronics; it was put
aside and a new power supply installed inside the computer. Also at the time
power supplies were half the price of today's.
On the PCB there are a D339 and 7500B chips.
I have found that schematics with these 2 chips (see included file).
Does it represent the actual circuit of the MAX-500ATX, I cannot tell.
Some measurements,... -
The sub developed a constant popping every couple seconds from woofer and power LED flickering with nothing but wall AC connected. Connecting an audio cable didn't change anything. It doesn't play but a second or two of audio in between the pops.
Opened it up and discovered the power supply is making a faint clicking or ticking sound.
I measured the amp's output to the woofer and it pulses up to 50mv DC to be driver. The pulses coincide with the power supply ticking/clicking.
I measured the power supply output going to the amp board and it too has this pulsing. Voltage cycles... -
Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming...
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