Magnavox 50MF231D/37

[jhd2112]

Re: Magnavox 50MF231D/37

Yea that’s is what I thought, I was figuring the E-buffer board was splitting the Va
65.5v power in half so pin two was labeled 30v so at ground it would be 30 to 32.5volts it is labeled 30v. I will check all the labels on the other boards tomorrow and post what I find. I could be chasing that ghost you told me about. Thank you for the help

[jhd2112]

Re: Magnavox 50MF231D/37

If the SSB board was bad, what symptom would it produce? Just grabbing at straws! Hope to get lucky.

[ljintexas]

Re: Magnavox 50MF231D/37

I have talked to two different techs who both told me that they resolved the four blinking red light error by replacing the Small Signal Board. Evidently it has the DC to DC converter for the 3.3volts and 5 volts on it. It can shut down the SMPS board.

[jhd2112]

Re: Magnavox 50MF231D/37

Check The F and G boards and found pin 4 labeled 35 Volts. But on board E, pin 2 is labeled 30 Volts. Check a lot of stuff but only thing I know is TV screen does not Light but can use remote and enter service mode and just get a blinking Green power on light on front panel. Screen does nothing but stay black. All Boards with LED green lights seem to turn on. Main signal board has two green lights lit, power supply one green lit, logic board has three led lights, power side green and two leds on left side one lights then second lights and blinks and first one turn off. Check for broken screen none, checked power supply, checked Logic board, and check EFG boards, checked X and Y but have power and all boards are ready to light. I want to thank every one for there dedication and Help. Got any Ideals?

[jhd2112]

Re: Magnavox 50MF231D/37

I was examining the Y main board and found two Voltage adjustments caps dose anyone know how to check and adjust these voltage board # are (VR5000 or V85000) and (VR500 or V8500) have added picture too! If voltage is off 2V maybe shut down start up process?
Does any one know how to check and adjust these voltage levels? Thanks from jhd2112

[tw2005]

Re: Magnavox 50MF231D/37

I would avoid touching those as they set the waveforms and without the service data or an oscilloscope you may never get them back to being correct. If you msut touch these, get a fine nikko pen and mark the position relevant to the trimpot case.

I don't know enough with these to point in any direction other than to check the buffers for shorts, check voltages, check all transistors to see if shorted, check all fuses on the sustains including those small green picofuses

[jhd2112]

Re: Magnavox 50MF231D/37

Check all Pico-Fuses and all other Fuses all Good. Replaced SSB main board and now has red led light on and flashes code 8. I believe the SSB main board is bad on the 1.2 volt power supply. and not able to convert signal. Thank you Badcaps Veteran tw2005 for all your help. the power supply to the EFG boards is good and power on X and Y board is Good. I will get another board and try again!