i had the problem of the inductors having cold joints. i fixed that and upon hooking it back up and powering it on, i heard a small pop and yes it was the fuse on the board. i soldered in a new one and attached everything and it would power up and make a low noise buzz from the zsus board and then shut off. i pinned down exactly where the buzz noise was coming from and it was one of the mosfets...? under the black heat sink. also the fuse i put in is not blowing.
SO, i took a small phillips head srcew driver and unscrewed all these mosfets/regulators from the back heatsink. then i proceeded to heat up the pins for the heatsink carefully removing it one side at a time. then after it was off, i desoldered each mosfet/voltage regulator that was under the heatsink.
Here is where i need help...
I am no electrical technician, but i set my ammeter to continuity/diode mode (maybe these are diodes that i desoldered?) and i put the positive lead to the center pin and checked the pins on each side (3 pins on each diode/mosfet/voltage regulator). all of them passed the test except one. how can i tell for sure if this modfet is indeed bad?
just need some wisdom from someone more skilled than me
thanks and god bless
EDIT:
I watched a youtube video of someone testing one of these from a samsung tv, he set the ammeter to diode mode, set positive on the center pin and checked the pins on each side. the bad one showed shorted (had continuity through it). is this the same with what i am doing? do i need to post pictures or part numbers? thanks in advance
EDIT 2: because i do not have a camera i will post a link to a thread from this forum that has the exact board i am working on. i will borrow a cell phone from my father when he gets back and take pics and upload them.
link to thread with the same board i am working on:
https://www.badcaps.net/forum/showthread.php?t=52379
also here is a link to the exact part: http://www.mouser.com/ds/2/149/FGPF4633-244016.pdf
seems this thing is called an IGBT. and it is attached to the black heatsink with a phillips head screw, after testing all of them (out of circuit) only one seems to be shorted.
SO, i took a small phillips head srcew driver and unscrewed all these mosfets/regulators from the back heatsink. then i proceeded to heat up the pins for the heatsink carefully removing it one side at a time. then after it was off, i desoldered each mosfet/voltage regulator that was under the heatsink.
Here is where i need help...
I am no electrical technician, but i set my ammeter to continuity/diode mode (maybe these are diodes that i desoldered?) and i put the positive lead to the center pin and checked the pins on each side (3 pins on each diode/mosfet/voltage regulator). all of them passed the test except one. how can i tell for sure if this modfet is indeed bad?
just need some wisdom from someone more skilled than me
thanks and god blessEDIT:
I watched a youtube video of someone testing one of these from a samsung tv, he set the ammeter to diode mode, set positive on the center pin and checked the pins on each side. the bad one showed shorted (had continuity through it). is this the same with what i am doing? do i need to post pictures or part numbers? thanks in advance
EDIT 2: because i do not have a camera i will post a link to a thread from this forum that has the exact board i am working on. i will borrow a cell phone from my father when he gets back and take pics and upload them.
link to thread with the same board i am working on:
https://www.badcaps.net/forum/showthread.php?t=52379
also here is a link to the exact part: http://www.mouser.com/ds/2/149/FGPF4633-244016.pdf
seems this thing is called an IGBT. and it is attached to the black heatsink with a phillips head screw, after testing all of them (out of circuit) only one seems to be shorted.
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