Magnavox 37MF321D-37 problem

[bulrich81305]

I have the Magnavox 37MF321D-37. It seems to be doing the 5 seconds to black but the power light isnt coming on at all. Ive tried the basic replacing the caps and diode on the power supply to no avail. I just wanted to see if you guys had any other input to check something I missed thanks

[tom66]

Re: Magnavox 37MF321D-37 problem

Pictures of all the boards and one of the overall chassis would help us help you.
Please use manage attachments to include them.

[bulrich81305]

Re: Magnavox 37MF321D-37 problem

Ok... Here are the pics front and back of the power and main boards and the overall chassis. please pardon the crappy pics (from my cell) if you look closely there is a zap mark on the back of the power board. I had it plugged in and bumped it and it shorted at the power socket and blew a fuse. It didn't however change the turning on issue or lack there of

[tom66]

Re: Magnavox 37MF321D-37 problem

OK, what brand and series is that blue capacitor on the power board, next to the other two that you replaced?

[bulrich81305]

Re: Magnavox 37MF321D-37 problem

it says phillips 03501 50v 1000u

[tom66]

Re: Magnavox 37MF321D-37 problem

May be low ESR but cannot be sure... if you can find another one that is low ESR could you swap it just to rule it out.

[bulrich81305]

Re: Magnavox 37MF321D-37 problem

ill have to order some i think that was my last.... gimme a couple days

[ComputerDoc4751]

Re: Magnavox 37MF321D-37 problem

Most cheap, low temp high ESR caps won't work. I've got 3 of those freakin boards, and putting the wrong caps in can cause you countless other problems! You can pull that board out and test it with it plugged in, but you have to connect loads for each of the 16V, +24v and -24v. I built a test jig to put a load on all 3 supplies, and LED's to show which are putting out voltage. Most problems that can't be fixed with just replacing caps seem to be in the 4A, 24volt line theres a power MOSFET STP45NF3LL that goes bad as well as diode 6074, an 8v 1/2w zener They're not so bad after fixing a few!