magnavox 37mf321d/37 burned power supply

[Agent24]

Re: magnavox 37mf321d/37 burned power supply

You could get the datasheet for it and then try to find something with matching specifications...

http://www.st.com/web/en/catalog/sen...chtype=keyword

[whiz62]

Re: magnavox 37mf321d/37 burned power supply

Thanks for the reply Agent24. The only thing I could find online was alternate from Digikey for 2,000 units for $1,324.00 or ebay from China, two for about 8 bucks. So I will go for cheap. The TV is old and not worth it. Just can't give up and it will make a good garage TV, if not I am not out that much. Will update post when I get the part. Just hoping someone found something compatible.

[Agent24]

Re: magnavox 37mf321d/37 burned power supply

Ones from China will likely be OK if the seller is good. Otherwise you may risk fakes. Read feedback carefully. Search for previous sales of the same part if you can. http://www.feedbackselector.com/ works well unless the seller has been using 'private' listings.

[whiz62]

Re: magnavox 37mf321d/37 burned power supply

Thanks for the info Agent24. Will check it out.

[whiz62]

Re: magnavox 37mf321d/37 burned power supply

I found a two pack on the mosfet at location 7071 from ebay part# p45nf3ll and also got an axial diode and resistor and scraped past the burn spot and soldered on and now have steady power led on front panel. But I don't have backlights but do have the 24 volts going to inverter board and fuses are good.

Looks like there is a slave inverter? got another two wire connector going to other side of panel and disappears under shell. Looks like a complete dis assembly. oh boy! These older tv's gotta lot of honking metal and screws!

Think I will let this rest a day or two. Thanks all for the help

[budm]

Re: magnavox 37mf321d/37 burned power supply

I found a two pack on the mosfet at location 7071 from ebay part# p45nf3ll and also got an axial diode and resistor and scraped past the burn spot and soldered on and now have steady power led on front panel. But I don't have backlights but do have the 24 volts going to inverter board and fuses are good.

Looks like there is a slave inverter? got another two wire connector going to other side of panel and disappears under shell. Looks like a complete dis assembly. oh boy! These older tv's gotta lot of honking metal and screws!

Think I will let this rest a day or two. Thanks all for the help

OK do you have BL-ON and DIM control signals to the Inveter also?

[whiz62]

Re: magnavox 37mf321d/37 burned power supply

Only other two connectors with wires are pin 12 bl-on= 0.02 volts and pin 13 e_pwm=3.2 volts. Looks like I still got a problem else where. Thanks all other info appreciated.

[budm]

Re: magnavox 37mf321d/37 burned power supply

Only other two connectors with wires are pin 12 bl-on= 0.02 volts and pin 13 e_pwm=3.2 volts. Looks like I still got a problem else where. Thanks all other info appreciated.

Main board is not sending out the BL-ON, you can force it on to see if you can get normal pictures on the screen using 1K between BL-ON and the 5VSTBY, BUT YOU MUST remove or cut the BL-ON wire going back to the main board FIRST!

[whiz62]

Re: magnavox 37mf321d/37 burned power supply

Thanks budm! Will try that in the morning and post results.

[whiz62]

Re: magnavox 37mf321d/37 burned power supply

Well, I dug into this and and found pin #9 on connector 1089 is where the 5vsbt is supposed to be but it isn't there. I was mistaken before and got in a hurry. Went to budm school for awhile today and that has helped. So I assume this is why I don't have back light.

here are readings on connector with all plugged but tcon:

1. 16v..reads w/ pwr button not on=18.50v..w/ pwr button on=18.50

2. 16v..reads w/ pwr button not on=18.50v..w/ pwr button on=18.50

3. bright adj.=0v&0v

4. inverter on/off w/ pwr button off= .05v.. w/ power on= 3.24V

5. F027 w/pwr button off=4.25v..w/pwr on= 4.77v

6. 0

7. 0

8. 0

9. standby..w/pwr button off=.01v..w/pwr on=1.24

10. 0

With main disconnected, only difference is pin 4 I get 3.06v and pin 9 is 0.
Still trying to figure this out. Thanks

[budm]

Re: magnavox 37mf321d/37 burned power supply

"4. inverter on/off w/ pwr button off= .05v.. w/ power on= 3.24V" That is good, you do have bl-on signal.

"9. standby..w/pwr button off=.01v..w/pwr on=1.24" Since you do have 24VDC for the inverter, then this ps-on is OK.

"3. bright adj.=0v&0v" This one is bad, try removing this wire and see if you will get backlights.

[whiz62]

Re: magnavox 37mf321d/37 burned power supply

Will do! Thanks so much.

[whiz62]

Re: magnavox 37mf321d/37 burned power supply

just disabled pin 3 wire and no backlight and no power led on front of tv when button pushed.

[budm]

Re: magnavox 37mf321d/37 burned power supply

That is the dimming control signal only so it should not affect anything else.
Do you still have standby Voltage?

[whiz62]

Re: magnavox 37mf321d/37 burned power supply

standby is 0.10 with or without power button.

[budm]

Re: magnavox 37mf321d/37 burned power supply

So now you also lost the PS-ON signal.
Is the standby power supply still working?

[whiz62]

Re: magnavox 37mf321d/37 burned power supply

still have pins 1&2 volts of 18.5v and 4.25v to pin 5, but nothing to inverter board. gonna give it a rest till tomorrow. Thanks budm!