Tip & How-To about Computers & Internet

Troubleshooting Motherboard Problems.

First,use your nose;often you can smell a fried component.next look for burned,discolored,or open components.next,remove the board and inspect both sides for broken traces,missing parts,etc.Use an ohmeter to check open or shorted diodes,resistors,caps,etc.Replace board and turn the unit on.If you don't own a "scope",buy a logic probe to use the half-split method(start at the center of the circuit.If signal is there,move toward speakers;ie find the signal).If no output at the auduo chip,change the chip.

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electrical burning smell coming from control panel on westinghouse dishwasher

Had the same issue with a 903sa. Strong burning smell. Continued to run for a while then just died. Opened the control panel (4 screws holding the plastic part at the top of the door on - open the door to access).

Mains feed into the controller was totally fried. Case was all melted. Very nasty. There was nothing obvious on the Board other than a mains resistor that looked like it had been pretty hot at some stage. The three pin mains connector (at least I think it was 3 pins) was just a big, charred bit of goop.

Feb 09, 2014 | Westinghouse Dishwashers

1 Answer

Power supply board not the problem- need further input please

Typically if one inspects the boards in question you may find evidence of heating and damage. Sometimes with newer solder having no lead, hot spots tend to leave cracks around the joints of parts heating and cooling and once they arc they fry components. One can usually smell a burnt component altho hard to describe the smell. I would look for burnt fuses on the power board where the power first enters the back of the tv, and some fuses are covered with a plastic sheath and looks like another type of component. A tester comes in handy... I suggest that you look more at the board that gives the high voltage to the TV screen, as there are step up transformers (square blocks) that give a lot of trouble and the transistors surrounding those blocks, usually 4 transformers. I would test for continuity around these areas but the transformers should be pulled from the board for a more accurate test. Inspect transistors (black with three prongs) usually has an aluminum heat - sink attached to it for cooling, anything more than 3 prongs is probably an IC or integrated circuit chip. These are more difficult to test. A diode will allow power one way but not the other so reversing the polarity tester tips will give you a voltage or nothing in reverse. Transistors are similar to a diode in that you can test it one way but it shouldn't be a reading the other to try to keep things simple. Typically when a transistor goes it will burn a hole in the face or on top. A capacitor looks like a mini soup can and swelling on top a hole on top or liquid stain under it is an indicator that it's bad. Typically the top is swelled and the plastic coating bares most of the top of the capacitor. If one inspects other capacitors in that area you can notice the difference even though indicators are slight at times. I would at very worse put the screen part away until you found a suitable tv model with a broken screen perhaps on kijiji. Typically it is a capacitor that has blown but may only lead to a partial solution to the problem if several parts are gone which is usually the case, a capacitor or two as well as a transformer or a transistor; and one must also inspect and test other components in that same area for success and to inspect the circuits for cracking around components especially where the hot areas are and one can usually see these hot areas due to the discoloration of the board in these areas. These hot areas are usually the problem. One overall solution is to build a big fan into these tv's lol and put surge protector bars on all your expensive electronic components.

Dec 05, 2013 | JVC LT-37X688 37 in. LCD HDTV

1 Answer

my tv smells like it's burning

Remove the back cover and look for discolored components(most likely coil or transfo),also unplug teh set after it has warmed up and touch components lightly to feel for overheating.i had burned coil in a similar set,around the pincushion circuit. good luck

Oct 27, 2009 | Sony FD Trinitron WEGA KV-36XBR800 36" TV

1 Answer

Stoped heating and had a smell like somthing electrical was burning? Fix it or buy a new one?

HI, normally, when you smell the burning electrical wires and board components, this will confirm a major capacitor malfunction. in this case, all electronic component will be fried or destroyed. these parts are the running diode,magnetron tube,cut-off fuse,noise filter and control board as well. all these parts will be costly to replaced, and it will be more cost effective to just cut your loss and purchase a new unit. the newer unit will be cheaper than the actual repair bill in this case.

Aug 06, 2009 | GE Spacemaker JVM1640SJ Microwave Oven

1 Answer

Blurry, purple cast to picture.

check the crt cap that is connected to your picture tube...it may be greenish inside...try to change the crt...and adjust the focus...

Sep 03, 2008 | Zenith Z25X22S 25" TV

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