electronics buffs in here please to identify this
- Thread starter Kanifee
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It's in an epoxy encapsulation so not a resistor or ceramic capacitor. There appears to be a white band at one end (crappy pic though) so it's polarised. Could possibly be a tantalum capacitor, but 390 is not a preferred value so unlikely I think.
Best guess would be a diode, possibly a 3.9v zener. Easy to tell if it's a diode, check the resistance with a multimeter (preferably analog) with the lead connected both ways. One way will measure a higher resistance than the other if it's a working diode. Checking if it's a zener will be more complex, you will need a voltage source (e.g. 9v battery) and a current limiting resistor (1k-4k7 should be fine). Connect battery, resistor and diode all in series. With the diode in one polarity you will read about 0.6v (standard silicon junction forward voltage), with the other polarity you will get the zener voltage (if it's a zener diode). If not you will get the full battery voltage.
Best guess would be a diode, possibly a 3.9v zener. Easy to tell if it's a diode, check the resistance with a multimeter (preferably analog) with the lead connected both ways. One way will measure a higher resistance than the other if it's a working diode. Checking if it's a zener will be more complex, you will need a voltage source (e.g. 9v battery) and a current limiting resistor (1k-4k7 should be fine). Connect battery, resistor and diode all in series. With the diode in one polarity you will read about 0.6v (standard silicon junction forward voltage), with the other polarity you will get the zener voltage (if it's a zener diode). If not you will get the full battery voltage.
mod is a media box, sorry for being a little vague, the components were populated right next to the cpu, they have designations of c9012,9013 and 9014. I had presumed they were some type of smd poly capacitor with the c designation but i dont want to solder caps to point if im not sure, there is a positive and negative polarity to the orientation on the board but thats about all i have.
Just a note, i solderd the wire on, i have ha dto move them to fit a custom cooling solution as they were slightly too raised, the legs that folded under though were too delicate!
Just a note, i solderd the wire on, i have ha dto move them to fit a custom cooling solution as they were slightly too raised, the legs that folded under though were too delicate!
Ok ive just got some eesults off of a number from a identical devise located somewere else on the board, slightly differant in numbers, this is a 330 not a 390 but it is called a Parallel voltage controlled resistance elements
Does this help determine value?
Does this help determine value?
if the silk screen says its C901? then i would say its a TANT, Judging by the size a tant-c what voltage i have no idea.
It's a 390uF 2v Polymer Aluminium capacitor. (assuming the partially obscured letter next to the polarity band is a lower case 'd').
Farnell show just one type at a rather eye watering £2.37 each (+vat) plus a hefty delivery charge. RS have a 470us part that would almost certainly be fine, but it's even more expensive at £3.39. Can't find any other UK suppliers that you can buy small quantities from. An expensive mistake...
Note that soldering these kind of high frequency decoupling caps onto bits of wire almost completely ruins their performance due to the extra inductance the wire adds, not a good idea.
Farnell show just one type at a rather eye watering £2.37 each (+vat) plus a hefty delivery charge. RS have a 470us part that would almost certainly be fine, but it's even more expensive at £3.39. Can't find any other UK suppliers that you can buy small quantities from. An expensive mistake...
Note that soldering these kind of high frequency decoupling caps onto bits of wire almost completely ruins their performance due to the extra inductance the wire adds, not a good idea.
Soldato
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Oh man, I hate soldering SMD's, good luck! 
well done identifying the cap... this thread proves that you should not be modding laptops if you are not really qualified to be taking one apart, its a whole different level to messing with desktops. I assume op slipped with screwdriver and knocked surface mount components off motherboard ?
looking at way you have attempted to solder a wire to it I would recommend you find a friend who knows how to solder as it needs someone who really knows there stuff to replace them without trashing the lappy mobo totally.
sorry to sound abit of a &^%$, but i worked in electronics for almost 10years and now through IT job fix several laptops a month and still struggle with them, they are a real nightmare!. (though usually involves just resoldering power sockets not other components)
good luck in getting it working again, fingers crossed you havn't ripped any track off the board, then things are gonna get scary
ps: as with any laptop you will have spare screws at end of job lolol
looking at way you have attempted to solder a wire to it I would recommend you find a friend who knows how to solder as it needs someone who really knows there stuff to replace them without trashing the lappy mobo totally.
sorry to sound abit of a &^%$, but i worked in electronics for almost 10years and now through IT job fix several laptops a month and still struggle with them, they are a real nightmare!. (though usually involves just resoldering power sockets not other components)
good luck in getting it working again, fingers crossed you havn't ripped any track off the board, then things are gonna get scary
ps: as with any laptop you will have spare screws at end of job lolol
Soldato
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I laugh at this becuase it's so true
, laptops are a real pain to repair sometimes, I hate them, I often find with a lot of laptops the hardest part is actually dissembling them and putting them back together properly, a real head ache sometimes.Thanks a lot for the help, id removed the caps on purpuse to make room for a cooler mod, larger heatsink but looking back it wasnt the smartest idea.
The soldering job isnt to clever but thats more to do with the fact the small leg had managed to come away from the boddy of the cap, i had dremeled away some of the body to try and expose more metal material but it didnt work so i just tryed copius amounts of solder.
Ive solderd smd parts before so shouldnt be too much of a hassle, just means i will have to place them back on the board and find an alternate method i suppose.
And yes i have a rarther worryingly large tub of screws from previous laptops ive had to pieces, funnily enough 90% for the power socket. i really ont understand why people find so hard to not snap it form the board or snap the center pin away completely!
The soldering job isnt to clever but thats more to do with the fact the small leg had managed to come away from the boddy of the cap, i had dremeled away some of the body to try and expose more metal material but it didnt work so i just tryed copius amounts of solder.
Ive solderd smd parts before so shouldnt be too much of a hassle, just means i will have to place them back on the board and find an alternate method i suppose.
And yes i have a rarther worryingly large tub of screws from previous laptops ive had to pieces, funnily enough 90% for the power socket. i really ont understand why people find so hard to not snap it form the board or snap the center pin away completely!
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