Dynex tv with model #32L200a12 turns on, but shows "please wait..." quickly...

[SCCronauer25]

I am trying to fix my Dynex tv. The PSB is new and so is the Control Board, but when I turn it on, I get "please wait..." on screen, then it quickly goes black. I have the back of it off and checking voltages shows 5v standby and 2.5v supply comes on going away/into PSB/Control Board, 24v is present on PSB (getting .4v on most, if not all, backlight lines, 5v to backlight is there also), the control board's heatsink staying hot to the touch, plus the 2.5v going away/into the PSB/Control Board, gives me the impression it is on. What else should I check for?

[nomoresonys]

post good clear straight on pictures of each board and one of the whole back as to see how everything is connected, use the go advanced to post pics.

[SCCronauer25]

Got it, will do.

[SCCronauer25]

Originally Posted by nomoresonys

post good clear straight on pictures of each board and one of the whole back as to see how everything is connected, use the go advanced to post pics.

Pics of the connections and boards. I can check specific voltages if asked to. I have also checked for the voltages I get on the top two backlight lines when I power on and it reads about 12v for each before the backlight turns off. I know that it technically works other than it saying "please wait..." before the screen just goes black with no more backlight while everything stays in the "powered on" state.

[nomoresonys]

ok start with connector x508, put your black probe on chassis ground, red probe on each pin, just probe the top to touch the metal, check each pin in standby (tv plugged in power off) take note of voltage, keep the probe where it is power tv on take note, report results, like pin 1 power-on, standby 0 volts powered on 3.3 volts, need pin label and condition in both standby and powered. Do that for each pin.

[nomoresonys]

good example of testing there: https://www.youtube.com/watch?v=XH9GfkGQX1I

[SCCronauer25]

Originally Posted by nomoresonys

ok start with connector x508, put your black probe on chassis ground, red probe on each pin, just probe the top to touch the metal, check each pin in standby (tv plugged in power off) take note of voltage, keep the probe where it is power tv on take note, report results, like pin 1 power-on, standby 0 volts powered on 3.3 volts, need pin label and condition in both standby and powered. Do that for each pin.

x508 connector voltages (powered off vs powered on) is as follows:

Standby mode plugged in and powered off:

pin 1: 0.000v
pin 2: 0.033v
pin 3: 0.033v
pin 4: 0.000v
pin 5: 0.000v
pin 6: 0.020v
pin 7: 0.002v
pin 8: 5.079v
pin 9: 0.001v
pin 10: 0.005v


Powered on mode:

pin 1: -0.005v
pin 2: 11.78v
pin 3: 11.78v
pin 4: -0.007v
pin 5: -0.007v
pin 6: 2.482v
pin 7: 5.000v
pin 8: 5.057v
pin 9: 2.535v
pin 10: 4.570v

[SCCronauer25]

Originally Posted by SCCronauer25

x508 connector voltages (powered off vs powered on) is as follows:

Standby mode plugged in and powered off:

pin 1: 0.000v
pin 2: 0.033v
pin 3: 0.033v
pin 4: 0.000v
pin 5: 0.000v
pin 6: 0.020v
pin 7: 0.002v
pin 8: 5.079v
pin 9: 0.001v
pin 10: 0.005v


Powered on mode:

pin 1: -0.005v
pin 2: 11.78v
pin 3: 11.78v
pin 4: -0.007v
pin 5: -0.007v
pin 6: 2.482v
pin 7: 5.000v
pin 8: 5.057v
pin 9: 2.535v
pin 10: 4.570v

pin 1: Labeled "GND"
pin 2: Labeled "12v"
pin 3: Labeled "12v"
pin 4: Labeled "GND"
pin 5: Labeled "GND"
pin 6: Labeled "PON"
pin 7: Labeled "5v-1"
pin 8: Labeled "5v-5"
pin 9: Labeled "PWM"
pin 10: Labeled "BON"

[CapLeaker]

So BLon is 5v but the backlights are off? That means you got bad backlights!

[SCCronauer25]

Originally Posted by CapLeaker

So BLon is 5v but the backlights are off? That means you got bad backlights!

I considered that, but, when the tv initially powers on, I see picture and backlights come on. Hence why I noted that I get the message "please wait..." then it goes black while staying on. This happens every time I power on, so, I can only assume backlight is still working.

Bad caps, possibly? ((I also noted that this is a "new-probably refurbished or taken from partly good tvs respectively" PSB and Control Board. So, I am not sure that is what the issue is. Unless there is a bad cap on another pcb behind the metal housing that everything is attached to (which I doubt, but who knows), maybe in between the metal and backlight panel where the wires go into it))

[SCCronauer25]

Originally Posted by SCCronauer25

Pics of the connections and boards. I can check specific voltages if asked to. I have also checked for the voltages I get on the top two backlight lines when I power on and it reads about 12v for each before the backlight turns off. I know that it technically works other than it saying "please wait..." before the screen just goes black with no more backlight while everything stays in the "powered on" state.

Pics of inside the backlight housing area. I will try and see tomorrow, possibly, if any of the lights do not come on. I am thinking they are ok, only because there are no noticeable dark areas of the screen when it does light at power on...

[nomoresonys]

ok, so you didn't waste any time and stripped it down, shows you're not lazy, be very careful with the panel, very easy to break them, specially on bigger sets, this 32 is much easier to manage. ok go ahead and ohm out your transformers on the inverter board, measurements on all of them should be very close to each other. meter in ohm mode, ohm testing done with tv UNPLUGGED from power, video example there, not your same tv but should give you the general idea:

https://www.youtube.com/watch?v=vNIWtrEHYsc

[SCCronauer25]

Originally Posted by nomoresonys

ok, so you didn't waste any time and stripped it down, shows you're not lazy, be very careful with the panel, very easy to break them, specially on bigger sets, this 32 is much easier to manage. ok go ahead and ohm out your transformers on the inverter board, measurements on all of them should be very close to each other. meter in ohm mode, ohm testing done with tv UNPLUGGED from power, video example there, not your same tv but should give you the general idea:

https://www.youtube.com/watch?v=vNIWtrEHYsc

Well, I guess moving it around to keep away from pets, having no rigidity, plus with my inability to keep it from twisting too much as I move it from one place to the other, has apparently taken its toll on one of the lights unfortunately, one end of the top bulb broke, right at the beginning of the blackened area of the bulb.


I still checked the coils and they seemed ok, all reading about 0.1-0.2 ohms.
However, it looks like this repair is a bust, as I don't think I will be able to find a bulb like the one that is needed. I am curious to see if the bulbs could just be replaced with LED's instead, but I am not sure if that would be a viable option, at least not without figuring out a way to drive them...

[nomoresonys]

it can be converted to led pretty cheaply, aliexpress sells kits for not much, probably ebay too.

[nomoresonys]

I meant to say ebay has them too but not as much to choose from as aliexpess.