Troubleshooting electronics...

[paulof]

Other than capacitors what are common components that usually die off ?
Are resistors ever likely to go bad ?
Is there other common signs to look for bad components other than capacitors ?

[medamotcha]

Re: Troubleshooting electronics...

Other than capacitors what are common components that usually die off ?
Are resistors ever likely to go bad ?
Is there other common signs to look for bad components other than capacitors ?

look for burns in the board ..is the most common....and look for cracks in the dieodes...the resisers you have to check the resistance or omes to see if bad.but im not a super tech...i know the basics...smell the board see if and were if burn't

[barefoot]

Re: Troubleshooting electronics...

I agree, First look for blow fuses. Then look for or smell for anything that shows damage. This can be a bubble on a transistor or computer chip or faint discoloration to blown caps. Also look for tail tail signs of oil under caps. Many repairs are just the one bad component. If it is not obvious check for bad solder joints with plenty of light and a magnifying glass. I things are not obvious, then obtain and trouble shoot with the schematic. Good luck.

[chipper]

Re: Troubleshooting electronics...

Other than capacitors what are common components that usually die off ?
Are resistors ever likely to go bad ?
Is there other common signs to look for bad components other than capacitors ?

While there are many tests that can be performed by a technician , the first really good tool to have is a multimeter to test the numerous parts of course , but looking can't always solve anything.

More times than not , there are no tell-tale signs of damage in electronics , as miniturized circuits are hidden from any magnification level. Serious problems should be looked at , if there are NO SIGNS , by someone who knows the particular component that you have. While dealing with the manufacturer can be the best thing , it is not always going to reveal the response that is usually expected or sought.

Resistors do go bad but are usually coupled with some very obvious circuit overload damage. Burning. From experience I have learned that "mixed" component parts are one tell-tale sign that the unit in question was not actually built by any company in particular IE : Sony , Toshiba , Hitachi , and others , if you see more than 2 manufacturers names on the small main chipsets , chances are the entire board is racked with compatibility problems which were accelarated by 1 failure or another.

These can be the most costly and difficult repairs due to a lack of reliance upon any 1 manufacturer specifications. If the circuit board in question is more than 5 yrs. old , it falls into this category. While subsequent units of the same type , have no names that can be quoted or sought. Like the Hitachi symbol on a Sony VCR unit. It already has 2 right there. Further looking will definately reveal many more , but the chipsets are the factor which I find unbelievable to expect to be working together.

On the contrary , if you only see 1 major brand name on chipsets , chances are the unit is of quality and not a mixed up compilation of circuits that has failed due to any sort of incompatibility. If these different chipsets are soldered together on 1 or 2 boards , it seems that nothing resolves the unit's problems and is usually called a lemon. Especially if someone has improvised with obviously differing brand names or parts on circuit boards. Their datasheets can explain some things but are complicated and not much help to those who do not understand schematics.

One of the worst signs you can come across is the fact that the main power supply is not working , does not heat up , or seems dead. That could mean someone has made that particular unit work before when it broke down , somewhere along the line. Refurbishing since 2000 has become a common practice and may have only been a temporary fix. These can lead to power supply failures because the integrated circuits are not rated to allow any tampering beyond their original specifications. Killing the power supply eventually. Don't forget that when a system of any kind runs on an overheating power supply as a result of problems it ages much faster and could have multiple problems internally. Fixing 1 thing will lead to another failure in alot of cases. Base your decisions on the condition of the power supply , as the wrong fuse is a good sign that the unit has had problems and is poofed.

Replacing a power supply can sometimes make the existing problem come to light , and burn out the supply in a month or so. It's a good guideline to look for similar parts all over the board and the unit. Hope this helps.