How to find bad electrolytic capacitors in the circuit board.
1) you observe and examine the electrolytic capacitors in the circuit board,specially close to the heat sink,IC ,transistors and the unit that emits more heat, usually bad electrolytic have bulged at top of it and also had may be bulged in bottom or at sides of it,this is the sign that capacitors is bad or going to be bad very soon,you can replace it with good another one same value and rating.
2) you observe and examine the electrolytic capacitors in the circuit board. some times it leaks by itself with some gooey electrolytic chemicals in the bottom and it leaks on the circuit board or stuck on the capacitor itself, this is also quick and good sign that capacitors became weak and bad and need to be replaced immediately.
3) observe and examine the electrolytic capacitors in the circuit board ,some times it explode at the top or at the sides or some times it completely vanishes from the circuit board due to power serge , power supply spike and also from lightening , in this case you will see only two leads or part of blown capacitor some times on the circuit board ,in this case also check nearby electrolytic capacitors and another related components that might needed replacement.
4) you observe and examine the electrolytic capacitor in the circuit board ,some capacitors at the top trying to tear it aluminium case and make small cracks due to internal bulged,this capacitor needed to be replaced, because sooner or latter it might going to be dried up internally.
Shutdown? sounds like a power supply problem to me, and one of the likely causes would be the IC regulator (IC1) within it. The IC would have 3 to 5 pins on it, is probably marked as STRxxxxx (the x represents its type number), and probably has intermittent partial internal failure, causing the symptoms you describe. With the whole combo unplugged from the wall, remove the top cover, locate this little device, note its type/part number, find out cost of the part, replace it, observing its pin orientation on the PCB.
You might also like to check all of the electrolytic capacitors on this board too to be sure - and replace every one of them. Capacitors are one of the biggest troublemakers in any power circuit, especially electrolytic types located near components which emit heat (such as ICs and transformers). You may need to (carefully) remove the DVD drive to gain access to the power sub-board underneath. Once the sub-board is out, you can examine it more closely, and do as above. The IC regulators in this series were usually rated around 12V or so, and for the most part, were reliable. Caps are cheap enough - just note the values of the originals before buying new ones, perhaps uprate the working voltages of some to be safe. Electrolytics have a negative stripe on one side of the 'cylinder' or 'can' - so observe their polarity when replacing - the positive (+) of the cap must match the (+) point on the board.
The good news is that this may not be a really expensive repair for an otherwise functioning DVD recorder, and at this stage, is confined to one circuit. However, this is just advice from my experience. Your best option is to order the correct part number for the IC due to its voltage rating and the internal components in it. The part cost will depend on who you deal with. Don't forget to check the power sub-board for dry soldering, cracks, burn marks around components, etc. Worth saving.
Capacitors used on a motherboard, and in a computer Power Supply, are Radial Aluminum Electrolytic Capacitors. (In regards to an eMachine. Some motherboards used in PC's are Solid Capacitors)
What if the problem IS an Electrolytic Capacitor in a Power Supply? Replace the Power Supply. Do NOT open it even unplugged from power.
Electrolytic Capacitors are designed to slowly build a charge, then release it all at once. This can be seen in a type of camera flash. These types of camera's use Electrolytic Capacitors in their flash unit.
[Think of a large swimming pool being filled slowly by a garden hose, then one wall of the pool is taken down all at once ]
An Electrolytic Capacitor can hold a charge for weeks, months, sometimes over a year.
If your finger/s touch the terminals on the bottom of an Electrolytic Capacitor, the charge can be released to YOU!
If your finger/s touch a circuit an Electrolytic Capacitor is in, or more than one capacitor, the charge could be released to YOU!
The shock can be Bad to Fatal.
Computer on a table, computer Unplugged from power, computer case open. Observe Anti-Static Precautions.
Check the capacitors on the motherboard out. Observe inside the Power Supply through the ventilation holes with a flashlight.
Need guidance in replacing the Power Supply, and/or recommendations for a Power Supply, please state in a Comment. Need the Model Number of the eMachines. Would appreciate hearing back from you.
Specifically, Electrolytic Capacitors used on the motherboard. (Radial Aluminum Electrolytic Capacitor), in the Voltage Regulator Circuit.
Part of what the motherboard Voltage Regulator Circuit does, is to provide steady, 'clean' voltage to the Processor, and within a certain tolerance range.
If a Processor does not receive voltage within a certain tight tolerance range, it turns off. (BIOS turns it off)
Check for visual signs of bad capacitors. (Computer off, unplugged from power, Anti-Static Precautions observed. Your inspection may also require using a flashlight)
Suggest you change the power supply unit. 'Sounds' like a faulty power supply. Suggest Electrolytic Capacitors have gone bad, in the power supply unit. Check the link below, to see what Electrolytic Capacitors look like, and what they look like when they have failed. These capacitors don't Always show the visual signs when they fail, but most of the time they do.
I do not suggest you open the power supply unit chassis to observe closer though, as the capacitors can hold a charge for a L-O-N-G time. Sometimes weeks, or months. (Sometimes up to a year) These capacitors are designed to slowly build a charge, then release it all at once. Should your fingers contact the terminals, of any of the larger capacitors, they could discharge their charge to You! These could result in a bad shock or worse. (Even if your fingers contact a circuit that the capacitors are in, if your fingers complete the circuit, you'll be the recipient of the released charge)
Power supply unit unplugged from power, you can take a flashlight, and look through the ventilation holes, or slots. See if you do observe any bulging, or leaking capacitors. When they leak, there is a yellowish, or brownish ooze that comes out. It may come out of the top, or bottom of the capacitor.
At the top of the capacitor is an X, or this -> lK. It this is split open, you have a bad capacitor.
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