reviving vizio power supply

[rubicondsrv]

I got a vizio 32"lcd with a bad power supply for $20

initialy unit failed to do anything when plugged in.

found a resistor blown, and replaced it, now yellow light on front flashes, and 5 volt lines read 4.2 and 2.3 volts.

also found a transistor with signs of arcing corisponding with arcing marks on the metal housing of the tv.

put arced transistor on my multimeter, it read 0

i assume that is bad


transistor is a1273, capacitors are "elite" brand, should i replace those at the same time as the transistor or not?

[retiredcaps]

Re: reviving vizio power supply

transistor is a1273, capacitors are "elite" brand, should i replace those at the same time as the transistor or not?

I would order new caps and replace the transistor. I would replace the transistor first and retest (to verify or find root cause). If it works, I would still replace them with some high quality low ESR caps.

[rubicondsrv]

Re: reviving vizio power supply

I looked up the elite caps, and am replacing the big ones with panasonic FM's

however the small ones are listed as "low impedance high ripple" what is sutibale for that?

also another cap is an elite EA cap wich isnt listed

[retiredcaps]

Re: reviving vizio power supply

however the small ones are listed as "low impedance high ripple" what is sutibale for that?

also another cap is an elite EA cap wich isnt listed

Sometimes the datasheets for caps are not available, so I just generally go with Panasonic FR, FM, and FC (in that order).

[rubicondsrv]

Re: reviving vizio power supply

I also need a equivalent transistor to A1273

[Th3_uN1Qu3]

Re: reviving vizio power supply

For jap/kor transistors you need to add 2S in front of the product code. So it's 2SA1273... nothing special. PNP -30V -2A 1W 120MHz. If you can't find an equivalent on your own please state your location so that we can point you to a parts distributor in your area.

[retiredcaps]

Re: reviving vizio power supply

findchips.com or ebay.com

There is one auction on ebay for $1 + $6 USD shipping.

[rubicondsrv]

Re: reviving vizio power supply

thanks, got the transistor from electronix

any reason to order a new primary cap?

[Krankshaft]

Re: reviving vizio power supply

Not unless it gives you warm fuzzies line caps even crap ones rarely fail and can be left alone.

[rubicondsrv]

Re: reviving vizio power supply

replaced the blown transistor, now both +5v lines read 4.2v when hooked up to the main board/led.

when tested without load they read 5v, but clearly dont have the power to drive the board.

still waiting on caps from digikey, will recap, then try again.

[mbates14]

Re: reviving vizio power supply

that component doesnt appear to be a resistor. it appears to be a FUSE.

[rubicondsrv]

Re: reviving vizio power supply

that component doesnt appear to be a resistor. it appears to be a FUSE.

the red bloby thing?

that is a .1ohm resistor that replaced a blue .1ohm resistor with a hole in the side.

[mbates14]

Re: reviving vizio power supply

ah, ok, so its a fusible resistor.

[rubicondsrv]

Re: reviving vizio power supply

ah, ok, so its a fusible resistor.

mabey, I just got it from a local shop, not sure what its specs are apart from being .1ohm and rated for 3 watts.