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Old 08-22-2013, 02:32 PM   #1
Pentium4
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Default Magnavox 32MF301B/F7 board swap

This Magnavox TV doesn't power on at all. It was very obvious why right when I opened it, the fuse is blown. And it looks like an extremely low quality power board. I'm guessing there are some shorted diodes somewhere and that the fuse would just blow again if replaced. The customer wants the TV back ASAP, so I was just going to do a board swap and replace the 85C caps.

The stock board is a BA17F8F0102 2 and the one I'm looking at online is a BA17F1F0102 5. It looks to be the same type of board with a smaller caps and a nichicon primary instead of HEC... Should it work correctly?
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Old 08-22-2013, 02:34 PM   #2
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Default Re: Magnavox 32MF301B/F7 board swap

I can't see why it wouldn't work.
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Old 08-22-2013, 02:43 PM   #3
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Default Re: Magnavox 32MF301B/F7 board swap

Just wanted to make sure, not a TV expert haha. I'm surprised Magnavox would use such a cheap board. Or is this just a rebranded "Funai" set?
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Old 08-22-2013, 02:47 PM   #4
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Default Re: Magnavox 32MF301B/F7 board swap

I would at least try the fuse. I had two of these exact boards that were indeed bad but did not have a blown fuse. The one I did get in with a blown fuse had been through a lightning power surge and it was indeed just the fuse. Pretty quick fix.

Both of the boards I replace had very obvious heat damage on them which yours does not have.

Anyway, based on my experience I'd sacrifice one.
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Old 08-22-2013, 02:48 PM   #5
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Default Re: Magnavox 32MF301B/F7 board swap

Quote:
Originally Posted by Pentium4 View Post
Just wanted to make sure, not a TV expert haha. I'm surprised Magnavox would use such a cheap board. Or is this just a rebranded "Funai" set?
Rebranded. There is a Phillips, Magnavox, and Emerson model that are all exactly the same set. I've had one of each unfortunately.

Heck if nothing else, jump the fuse temporarily to see if it powers up. What's the worst that can happen, smoke?

J/K of course

In all seriousness though try the fuse.

Last edited by aaronwt6; 08-22-2013 at 03:21 PM..
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Old 08-22-2013, 03:00 PM   #6
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Default Re: Magnavox 32MF301B/F7 board swap

Don't jumper the fuse. You can replace it with a new one, but DON'T jumper it!
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Old 08-22-2013, 03:08 PM   #7
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Default Re: Magnavox 32MF301B/F7 board swap

Haha alright thanks I'll look around my pile of scrap to see if I can find a suitable fuse
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Old 08-22-2013, 03:13 PM   #8
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Default Re: Magnavox 32MF301B/F7 board swap

One of those that blow out the power MOSFET and related conponents around it, look for shorted Diode in the secondary side or the load which more likely to cause this simple two-transistor switching power supply to fail.
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Old 08-22-2013, 03:20 PM   #9
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Default Re: Magnavox 32MF301B/F7 board swap

Quote:
Originally Posted by tom66 View Post
Don't jumper the fuse. You can replace it with a new one, but DON'T jumper it!
I really should have changed that completely. I was trying to joke around. Bad idea.
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