32ME402V/F7 no power on

[mcross]

I have 2 of these both have a BA21F0F0102 power supply, one is ver:1 and ver: 3 (ex BA21F0F0102 1 ) . the big transformer has a high pitched whine when you plug tv in. No stb light, tested diodes , good.
only reading i get on ps is
2.30 volts
big cap is 160v
any ideas?

Mike

[CapLeaker]

Re: 32ME402V/F7 no power on

Well... are both PSU's doing the same thing? On the top right of the PSU there is a ribbon cable with a pin out. Measure everything and post it with name and volts measured. Just by saying you got 2.3V, I have no idea where. Same thing, if would I tell you there is beer in the fridge and don't tell you in which fridge the beer is.

[mcross]

Re: 32ME402V/F7 no power on

Sorry, will get all and post, the 2.3v is stb voltage
mike

[Caleb]

Re: 32ME402V/F7 no power on

have you checked the smd diodes on the back of the power board? also check all zener diodes in the primary around the fet

[CapLeaker]

Re: 32ME402V/F7 no power on

disconnect the main board and see if the STBY voltage comes up on the PSU

[budm]

Re: 32ME402V/F7 no power on

disconnect the main board and see if the stby voltage comes up on the psu

have you checked the smd diodes on the back of the power board? Also check all zener diodes in the primary around the fet

+1.

[mcross]

Re: 32ME402V/F7 no power on

Disconnected the main , stb comes up to 3.3v (good), 12v and 24v pins are 8.94v, Checked diodes all look good. From what i have read this is common on this psu and sim versions . any other ideas. Also to make things clear, i have 2 of theses tv's both doing the same thing. as soon as they are plugged in the big transformer starts a high pitched whine, no other symptoms. I added a pic of the other ver of the board, This one has z-diodes where the other has none, 2 by the big transformer and 3 on the cold side 2 of which are by the led back light connector
Mike

[budm]

Re: 32ME402V/F7 no power on

"Disconnected the main , stb comes up to 3.3v (good), 12v and 24v pins are 8.94v"
I do not see 12V pin, I see switched 21V and 24V pins.
When the main board is not connected, there will be no PS-ON signal to turn on the switched 21V or the switched 24VDC power supply sections, so what you have error Voltage readings on the 21V, and 24V pins.
What you need to do next is to check the resistance between the STBY pin of the main board against ground to see if it shows low resistance, it can be that the main board is drawing too much current from the power supply, or the power supply STBY is too weak.
You can also do the load test on the stby with resistor to see if it can handle 0.5A or so.
CN1001, the smaller black connector for the smaller flat white ribbon cable is for the LEDs.
Pictures provided by SHOPJIMMY.
http://www.shopjimmy.com/catalogsear...?q=BA21F0F0102

[mcross]

Re: 32ME402V/F7 no power on

these are present with main disconnected not forced on

stb = 3.3v

24v = 8.83v


21v = 7.56v

[mcross]

Re: 32ME402V/F7 no power on

main board stb pin shows no resistance , bad main.
mike

[budm]

Re: 32ME402V/F7 no power on

OK, I traced out the bottom side of the board, there are three output windings on the secondary side of the power transformer.
D656 (SMD) is for negative power supply, D653 is for one of the two positive power supply, D650/651 for second positive power supply.
So just POWER UP the power supply board by itself, check the DCV between the two legs of the cap c652, C653, and C656.