Mangavox 50ME314V/F7 "Funai junk"

[heavymachines]

Re: Mangavox 50ME314V/F7 "Funai junk"

i was afraid you were going to say that so main is messed up.

[heavymachines]

Re: Mangavox 50ME314V/F7 "Funai junk"

So are we 100% certain its the main is bad because it is tad pricey.

[budm]

Re: Mangavox 50ME314V/F7 "Funai junk"

If you can disconnect just the BL-ON wire going back to the main board first and then use 330~470 Ohms resistor between BL-ON and the 3.3V on the power supply board to force on the backlights (it may need Dim control signal forcing too), if the backlights do come on but you do not see any pictures on the screen then you have more than just bad BL-ON signal but other problem as well.

[heavymachines]

Re: Mangavox 50ME314V/F7 "Funai junk"

Well don't think that is possible as the main and power supply is linked with a ribbon and there is no pinout for it. even if there was how would i disconnect 1 pin on a ribbon?

[CapLeaker]

Re: Mangavox 50ME314V/F7 "Funai junk"

I think those boards use jumpers. So find the BLon jumper and figure out the pin on the connector for the ribbon cable. Remove one side of the BLon jumper and verify that it is not making continuity to the connector. Apply power to the other end. Done.

[heavymachines]

Re: Mangavox 50ME314V/F7 "Funai junk"

Ok update i ended up taking a razor and cutting the bl-sw trace back to main.

Then i jumped power from 3.3 to bl-sw tv came on for a second then turn off made a weird electrical arc sound over and over i think some call this a chirp. Anyhow the ic3101 gets really hot now. So i think i might need this kit from sj http://www.shopjimmy.com/magnavox-a4...14v-f7-ds1.htm


i think we have found the problem. Thanks

[CapLeaker]

Re: Mangavox 50ME314V/F7 "Funai junk"

I wonder how much more money a new main board is, compared to that kit?
Also at this point, I'd like to see the PSU run by itself and stay on with the back lights connected.

[heavymachines]

Re: Mangavox 50ME314V/F7 "Funai junk"

I wonder how much more money a new main board is, compared to that kit?
Also at this point, I'd like to see the PSU run by itself and stay on with the back lights connected.

Mains so far around 60 to 70 bucks. 20 for kit is a hefty savings and i can do it with confidence. But yeah i agree we need to get that to run P/S by itself however i just cannot find standby. Perhaps one damaged the other somehow, if so then it would be fairly catastrophic.. Power supplies 50 so far that i find rather fix it if i can.

[heavymachines]

Re: Mangavox 50ME314V/F7 "Funai junk"

Then again it gets voltages when main hooked up except backlights before chirping problem. However when forced backlights it did come on for short bit before main caused power supply to chirp and main cpu gets hot which it didn't do before forced backlights.



And i did cut the trace and no continuity to pin. So IDK.


Like i said these funai's are something else.

[aaronwt6]

Re: Mangavox 50ME314V/F7 "Funai junk"

My typical experience with nearly all of the 2011-2014 Funai crap (all screen sizes) are as follows:

If the power supply is producing any voltages but the TV doesn't turn on, main is bad.

If the TV does absolutely nothing and makes no noise when plugged in, power supply is bad.

If the TV attempts to turn on (red light flashes a few times but then goes back solid), failed LEDs on the backlights. It can sometimes be accompanied by a brief flash but many times not. A lot of the 40" and smaller ones have only one series of LEDs so if one LED is open, then no flash.

I realize that there are exceptions to everything but the above runs pretty true for most Funai based sets that utilize the two board configuration from that era.

[budm]

Re: Mangavox 50ME314V/F7 "Funai junk"

Mains so far around 60 to 70 bucks. 20 for kit is a hefty savings and i can do it with confidence. But yeah i agree we need to get that to run P/S by itself however i just cannot find standby. Perhaps one damaged the other somehow, if so then it would be fairly catastrophic.. Power supplies 50 so far that i find rather fix it if i can.

ALL +3.3 is the Standby Voltage that should be present at all time as long as the TV is plugged into the AC outlet.

[heavymachines]

Re: Mangavox 50ME314V/F7 "Funai junk"

ALL +3.3 is the Standby Voltage that should be present at all time as long as the TV is plugged into the AC outlet.

Ok and without main it only puts out .006v so how on earth does this thing have voltages with main hooked up before the chirping problem.

[budm]

Re: Mangavox 50ME314V/F7 "Funai junk"

Are you sure that you are getting 0.006V at the jumper that has label ALL +3.3V? Not making any sense to me.
Your board uses about the same topology as in the attached PDF.

[heavymachines]

Re: Mangavox 50ME314V/F7 "Funai junk"

Are you sure that you are getting 0.006V at the jumper that has label ALL +3.3V? Not making any sense to me.
Your board uses about the same topology as in the attached PDF.

Well i checked with with 2 different dmm and checked batteries. So yeah i am pretty sure. With main hooked up before the chirp problem if i remember right it was little 3.27v volt ill recheck this forum. So i only get .006 with main disconnected. As to why i have just no idea something is overlooked it has to be.

[vinceroger69]

Re: Mangavox 50ME314V/F7 "Funai junk"

copied from your post 17
As follows
ALL 3.3V = 3.27v
PON-H2 = 1.069v
PON21V = 21.24v
PROTECT3 = .163
BL-SW (BL-ON)= .00

so maybe when you tried to force on the backlight it has now damaged the power supply ?

[heavymachines]

Re: Mangavox 50ME314V/F7 "Funai junk"

copied from your post 17
As follows
ALL 3.3V = 3.27v
PON-H2 = 1.069v
PON21V = 21.24v
PROTECT3 = .163
BL-SW (BL-ON)= .00

so possible when you tried to force on the backlight it has now damaged the power supply

No because i could never find standby with main disconnected right from the beginning. Otherwise i would say that is plausable. However possible damaged the cpu i think might be plausible but i did exactly as directed. This is why i have such a hard time understanding this alien tv and asked for help its a horrible design in my opinion.


Now on other hand we could have found a weakness in main with a preexisting problem in power supply idk

[heavymachines]

Re: Mangavox 50ME314V/F7 "Funai junk"

Are you sure that you are getting 0.006V at the jumper that has label ALL +3.3V? Not making any sense to me.
Your board uses about the same topology as in the attached PDF.

Budm if u look on first page in this schematic the p-on-h2 signal goes to a relay all +3.3v is provided by main to power supply and reset is fed back to main from power supply according to the arrow direction on the lines. indeed this is very odd design.

[budm]

Re: Mangavox 50ME314V/F7 "Funai junk"

Per block diagram page 9-10 of the schematic I provided as a refernce, the CN501 PIN 8 AL+3.3V is generated by IC651/Q657 which gets the input Voltage from the AMP+13V.
P-ON-H2 does not control the AL+3.3V supply.
BTW:
PROTECT3 = .163v, it should be around 2~3V if the LED backlights circuits are OK. But right now we need to deal with the AL+3.3V first which should be present without other board connected.

[heavymachines]

Re: Mangavox 50ME314V/F7 "Funai junk"

Ok where to start? ill start looking around. See why we don't have all +3.3v. but still think its odd i had it with main connected and don't have it without main.




is it possible to be an error in schematic?

[heavymachines]

Re: Mangavox 50ME314V/F7 "Funai junk"

Per block diagram page 9-10 of the schematic I provided as a refernce, the CN501 PIN 8 AL+3.3V is generated by IC651/Q657 which gets the input Voltage from the AMP+13V.
P-ON-H2 does not control the AL+3.3V supply.
BTW:
PROTECT3 = .163v, it should be around 2~3V if the LED backlights circuits are OK. But right now we need to deal with the AL+3.3V first which should be present without other board connected.

Something is not right. Can't find ic651 or q657 calling it quits for now. Nail back into it Monday.