Blown Capacitor on Samsung SV-5000W VCR
Blown capacitors are a common problem with VCRs. In this case I simply overloaded the unit, using it not just as a video player but also as a PAL to NTSC converter, since it had both input and output ports.
Symptom: unit not powering on; power light flashing red
Remove covers, being sure to label all screws. BE GENTLE when doing this - the plastic is brittle.
Scan the printed circuit board for faulty capacitors. Can you see the blown one in the picture below?
Look closer!
It's the one with the convex top. See how the other capacitors have flat tops? This one swelled and then blew right where the three lines meet - hence the holes at that point. This capacitor is now dead, and must be replaced. Fortunately our picture also tells us that it's a 1000μF unit with a maximum rated voltage of 16v. The capacitance is the most important figure.
Unless there's an electronics store nearby, you'll need to send away for the capacitor. They're easily available on eBay.
Removing this capacitor (and you WILL have to remove it) is the greatest difficulty. The only way to get at the underside of this PCB is to disassemble the entire VCR or to cut a hole through the plastic floor of the VCR. Disassembling the VCR completely is impossible, as there are too many parts, and it would take *ages*. Instead, measure the distance from the edges of the PCB to the capacitor, turn it upside down, and carefully cut a large hole over the spot where the capacitor is. Your measurements should tell you which stubs are those of the blown capacitor. Now the capacitor will be exposed both above and below.
Get your soldering iron. If you have a solder removal kit, so much the better. Firmly gripping and pulling the capacitor with one hand, use the other hand to heat the relevant stubs on the rear side of the PCB with the soldering iron. It will eventually pull free. Two holes will be left in the PCB.
Now, being sure to remember the polarity of the capacitor (do NOT install the new one backwards!), thread the new capacitor through the holes in the PCB and bend them so that the capacitor doesn't fall back through again. Turn the player upside down so that the stubby side is facing up.
That's the old capacitor at the top of the image. I just put it in for comparison. But the important thing here is the hole which I cut in the plastic case to get at the bottom of the capacitor, and the legs of the capacitor, which you can see threaded through the holes and bent away from each other.
Bend them away from each other, right at the surface of the PCB. Now VERY CAREFULLY melt a drop of solder onto each point of contact. When you're satisfied (test this process on a dead PCB first of all) very gingerly snip the feet of the capacitor so that they are no longer protruding.
Plug the unit in and test it. If it's functioning, you're done! Congratulations! If not, go through the process again; there may be another capacitor blown.
Reassemble the unit. Hopefully you remembered to label the screws!
Enjoy your old video tapes!
Symptom: unit not powering on; power light flashing red
Remove covers, being sure to label all screws. BE GENTLE when doing this - the plastic is brittle.Scan the printed circuit board for faulty capacitors. Can you see the blown one in the picture below?
Look closer!
It's the one with the convex top. See how the other capacitors have flat tops? This one swelled and then blew right where the three lines meet - hence the holes at that point. This capacitor is now dead, and must be replaced. Fortunately our picture also tells us that it's a 1000μF unit with a maximum rated voltage of 16v. The capacitance is the most important figure.Unless there's an electronics store nearby, you'll need to send away for the capacitor. They're easily available on eBay.
Removing this capacitor (and you WILL have to remove it) is the greatest difficulty. The only way to get at the underside of this PCB is to disassemble the entire VCR or to cut a hole through the plastic floor of the VCR. Disassembling the VCR completely is impossible, as there are too many parts, and it would take *ages*. Instead, measure the distance from the edges of the PCB to the capacitor, turn it upside down, and carefully cut a large hole over the spot where the capacitor is. Your measurements should tell you which stubs are those of the blown capacitor. Now the capacitor will be exposed both above and below.
Get your soldering iron. If you have a solder removal kit, so much the better. Firmly gripping and pulling the capacitor with one hand, use the other hand to heat the relevant stubs on the rear side of the PCB with the soldering iron. It will eventually pull free. Two holes will be left in the PCB.
Now, being sure to remember the polarity of the capacitor (do NOT install the new one backwards!), thread the new capacitor through the holes in the PCB and bend them so that the capacitor doesn't fall back through again. Turn the player upside down so that the stubby side is facing up.
That's the old capacitor at the top of the image. I just put it in for comparison. But the important thing here is the hole which I cut in the plastic case to get at the bottom of the capacitor, and the legs of the capacitor, which you can see threaded through the holes and bent away from each other.Bend them away from each other, right at the surface of the PCB. Now VERY CAREFULLY melt a drop of solder onto each point of contact. When you're satisfied (test this process on a dead PCB first of all) very gingerly snip the feet of the capacitor so that they are no longer protruding.
Plug the unit in and test it. If it's functioning, you're done! Congratulations! If not, go through the process again; there may be another capacitor blown.
Reassemble the unit. Hopefully you remembered to label the screws!
Enjoy your old video tapes!
Labels: Brian Ó Broin, capacitor, disassembly, electrolytic, multi-region, PCB, power, reassembly, Samsung, solder, SV-5000W, VCR
posted by sacsanua at 12:41 PM
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