Hisense rsag7.820.5687 no power no standby light

[EUWest]

Hi!

I have a power supply and on the TV no standby and no power. Have already installed a replacement power supply but the same problem.

When I test both power supplies the main capacitors while plugged in, I get 0v.

What could be the reason for this?

[lotas]

Re: Hisense rsag7.820.5687 no power no standby light

Is it a switch? Check if the contacts are jumpered on it.

[Diah]

Re: Hisense rsag7.820.5687 no power no standby light

yes its switch

[lotas]

Re: Hisense rsag7.820.5687 no power no standby light

Then, when turned on, red with blue and green with yellow should be closed.

[EUWest]

Re: Hisense rsag7.820.5687 no power no standby light

Hell no, switch was turned off while i was testing.

Now i have standby light but it wont turn on

[Diah]

Re: Hisense rsag7.820.5687 no power no standby light

Hell no, switch was turned off while i was testing.

Now i have standby light but it wont turn on

lol.. put back yours original power boards first and tell what voltage you have on the socket which it go to main boards

[EUWest]

Re: Hisense rsag7.820.5687 no power no standby light

But back original psu and get this voltages

19.6
19.6
0
0
12.15
12.15
0
0.004
0
0

Standby at 0.004 way to low. There is a buzzing sound on psu. Does this correlate with standby voltage?

Values are same connected or not with Mainboard.

[nomoresonys]

Re: Hisense rsag7.820.5687 no power no standby light

One easy thing to check when powerboard is noisy, is check all the solder joints and reflow any that look suspect, being careful not to bridge anything, some can really be hard to detect, a wiggle of the joint can detect a bad solder joint too, examples of bad joints: https://www.google.com/search?q=bad+...ih=607&dpr=1.5

[EUWest]

Re: Hisense rsag7.820.5687 no power no standby light

Thanks for this hind. Will give it a try tomorrow and Also test voltages on spare psu which i bought

[Diah]

Re: Hisense rsag7.820.5687 no power no standby light

But back original psu and get this voltages

19.6
19.6
0
0
12.15
12.15
0
0.004
0
0

Standby at 0.004 way to low. There is a buzzing sound on psu. Does this correlate with standby voltage?

Values are same connected or not with Mainboard.

please name the pins which read this value... so we do know where and what.

[R_J]

Re: Hisense rsag7.820.5687 no power no standby light

STB is the power supply ON/OFF signal that originates from the main board it is not a "standby" produced by the power supply. Your fault is likely the main board.

[EUWest]

Re: Hisense rsag7.820.5687 no power no standby light

Resoldering some joints fixed it. But there is still a loud buzzing sound while tv starts.

And even if its turned off, there is a buzzing sound too.
What can it be?

[Diah]

Re: Hisense rsag7.820.5687 no power no standby light

first time i hear Hisense get cold / crack soldering joint... any way... plug the tv out from wall... and play with its Switch on / off how much you can... it could be the switch its contact not in tact so there are sparking.

for further show us the place you re soldered.

[EUWest]

Re: Hisense rsag7.820.5687 no power no standby light

Uploaded and marked resoldered Pins.

Turning on off switch doesnt fix buzzing sound

[Diah]

Re: Hisense rsag7.820.5687 no power no standby light

Uploaded and marked resoldered Pins.

Turning on off switch doesnt fix buzzing sound

you wrote you have replacement power supply, so use it and see if the buzzing remain.

[EUWest]

Re: Hisense rsag7.820.5687 no power no standby light

Replacement psu doesnt buzz. So its specific to this psu. But however Replacement psu isnt working

[nomoresonys]

Re: Hisense rsag7.820.5687 no power no standby light

Use a hairdryer to heat up those 5 electrolytic capacitors for a couple few minutes, then try it, see if there's any difference in the noise, don't wait til it cools down try it while it's still hot.

[Diah]

Re: Hisense rsag7.820.5687 no power no standby light

from yours re soldering didn't see any effect of issue TV wont tun on..

you may had other issue before and it went out open.. for example the BL .. you have 2 Group you need to compare it currents if there any differences

[nomoresonys]

Re: Hisense rsag7.820.5687 no power no standby light

Can easily check all the diodes and resistors on top of the board, youtube for tutorials if needed.

[nomoresonys]

Re: Hisense rsag7.820.5687 no power no standby light

Also check the 3 pin components you see on heatsinks and one other, they appear to be transistors, check that none of the three pins are shorted to any of the others on the component, can look up a datasheet by putting in the info on top of component if needed. There are some 3 pin diodes that look just like transistors that will show continuity on the back 2 pins, so if ever in doubt about what you are dealing with, look up the datasheet.