Magnavox 37MF321D/37 - Green light on steady

[b4ugobye]

My 37MF321D/37 TV is having an issue which isn't consistent with others. As soon as I plug it in, the green light is on (as opposed to standby) and it is steady. I opened it up and looked on the power board and the video to look for bulging or leaking caps, but see nothing wrong visually. Nothing occurs when hitting the power button, but when i try the remote, the green light flickers as if it is trying to do something, but besides the green light, there is really no sign of life. Every post I have read, people have a blinking light... where I have a steady light, so any ideas would be very appreciated.

[TechShui]

Re: Magnavox 37MF321D/37 - Green light on steady

Consistent or not, it is still likely a scaler board issue.

These models all seem to have the same scaler board:

32MF321D
37MF321D
42MF321D

The power boards are also a common problem as the capacitors tend to blow after 2 years or so.

I would suggest check the voltages on the power board.

Are you getting 24V and 16V on the plug from the power board to the scaler board?
How about the 12-pin plug opposite that? 24V should be there too.

At least that way you rule out the power board.

EDIT: Keep in mind the caps can fail without bulging. I think this model has a lone 25V 2200uf which is usually the first to blow. However, it's still better to replace all three, to avoid future problems

[shelby5041]

Re: Magnavox 37MF321D/37 - Green light on steady

hi on my magnavox tv same model....when i plug tv in tv does not power on and i get no light on front........but the backlight flickers continuosly

i get 16v and 24v voltage going to scaler but i dont get 24v going to inverter..i get fluctuating voltages from low to high....as backlight flickers the voltages go up and down.........

i do not have a power light at all no blue or red on front.....

any ideas?

[aaronwt6]

Re: Magnavox 37MF321D/37 - Green light on steady

Which TV do you actually have? In the other thread you started you've stated it's the 32". The 37" power supply is much more prone to diode failures. Diodes ZD902, ZD906, and ZD908 are very common failures in the 37" version. Please post pictures of your supply and verify the TV model.

[aaronwt6]

Re: Magnavox 37MF321D/37 - Green light on steady

If you do have the 37" version, here are the part numbers for those Diodes. I'd recommend replacing all of them at the same time.

ZD902 - P6KE120A
ZD904 - P6KE120A
ZD906 - 4KE250A-E3
ZD908 - BZX79-B18

I just repaired several of these myself by replacing the capacitors and diodes with 100% success. Also, what capacitors did you use?

[shelby5041]

Re: Magnavox 37MF321D/37 - Green light on steady

32mf231d/37

[shelby5041]

Re: Magnavox 37MF321D/37 - Green light on steady

right now trying to pinpoint if ps or main issue

[shelby5041]

Re: Magnavox 37MF321D/37 - Green light on steady

i replaced caps with panasonic from digikey...........

[shelby5041]

Re: Magnavox 37MF321D/37 - Green light on steady

should this tv have standby voltage?......mine has 1.2v

[shelby5041]

Re: Magnavox 37MF321D/37 - Green light on steady




here is a photo

[aaronwt6]

Re: Magnavox 37MF321D/37 - Green light on steady

Yes, in fact I believe this power supply outputs 12V to the main at all times. The main has regulators on it that are always active. Not very efficient but the TV is older.

You'll have to wait for someone else to chime in on the problem. I've never had this particular supply with anything other than bad capacitors. The 37" version is typically more problematic.

[shelby5041]

Re: Magnavox 37MF321D/37 - Green light on steady

well thanks....i ordered a ps today for 22.95 shipped.....if it doesnt fix issue then i guess i assume its a mainboartd issue ,,,,,was hoping to find someone who repaired one of these and what they did

[shelby5041]

Re: Magnavox 37MF321D/37 - Green light on steady

yes it seems everyone who has repaired these just replaces the 3 caps and fixed....not mine though.......replaced the 3 caps and still wont power on just backlights flicker and thats it

[shelby5041]

Re: Magnavox 37MF321D/37 - Green light on steady

although i did order a ps today im going to make a guess and say the main board is bad because i do have 16 and 24 volts coimg out of ps to main board....

so i would say ps is probably good but since a ps is only 22.00 i will try that and if it doesnt fix issue i will resell the ps on ebay and buy a mainbaord for about 50.00 and hopefully will have a fixed tv.....

any input would be appreciated

thanks