Sony XBR-65X850E power supply board diode replacement

[Tnmg]

I have a Sony XBR-65X850E that when plugged in buzzes for a few seconds about 5-7 times but the screen never comes on. It looks like one of the four diodes on the main power supply board are bad. I'd like to replace all four at the same time. The diodes that are bad are the D750, D751, D752 and D753. The S750 looks discolored and fails the diode test on the board. It hasn't been removed from the board yet for testing.

Are all four of these the same diode? I saw a video that called the discolored one a Schottky 5150 diode. How can I make sure to get the right diodes for these?

Thanks!

[dskall]

Re: Sony XBR-65X850E power supply board diode replacement

What are the numbers on them? All 5150?

[nomoresonys]

Re: Sony XBR-65X850E power supply board diode replacement

not seeing an S750, where is it? if you mean D750, take it out of circuit and recheck it, it's the only one that failed the test?

[R_J]

Re: Sony XBR-65X850E power supply board diode replacement

All four diodes are the same, they are setup as a bridge.

I believe the S750 is a typ0, should be D750

[Tnmg]

Re: Sony XBR-65X850E power supply board diode replacement

What are the numbers on them? All 5150?

That's what they look like. I haven't taken them out yet.

[Tnmg]

Re: Sony XBR-65X850E power supply board diode replacement

All four diodes are the same, they are setup as a bridge.

I believe the S750 is a typ0, should be D750

That’s correct. Typo indeed. The discolored one is D750.

So all four should be the same? Any way to confirm they are Schottky 5150s? I saw a multipack ld them on Amazon but don’t know how to verify they’re the right ones.

[Tnmg]

Re: Sony XBR-65X850E power supply board diode replacement

not seeing an S750, where is it? if you mean D750, take it out of circuit and recheck it, it's the only one that failed the test?

That's correct, it's D750. I haven't taken them out, just checked them on the board. Figured I'd just change them all once I got the new ones.

[nomoresonys]

Re: Sony XBR-65X850E power supply board diode replacement

just order them by the numbers on the diode, can't go wrong that way.

[nomoresonys]

Re: Sony XBR-65X850E power supply board diode replacement

best way to confirm is take out of circuit and retest, when you put them back in just make sure the stripe is in the right direction. Usually adding a little new solder to the joints makes the component come out much easier.

[Tnmg]

Re: Sony XBR-65X850E power supply board diode replacement

just order them by the numbers on the diode, can't go wrong that way.

Will do. Thanks!

[Tnmg]

Re: Sony XBR-65X850E power supply board diode replacement

Replaced the diode that appeared to have failed and power supply works now. Have a new problem but I'll make a separate post for that. Thanks for the help.

[Tnmg]

Re: Sony XBR-65X850E power supply board diode replacement

So, the power supply board is good. The TV boots up and a solid blue line shows up on the right side of the screen centered on a 6 inch black vertical bar. I attached a pic to see. I don't have the remote from the tv so I can't go any farther with the tv setup. Everything up this point seems to be working. Volume, horizontal lines are good. Rest of the screen is good vertically.

The blue line brightens and dims in intensity but the black vertical bar never goes away.

Any help is greatly appreciated.

[neilc6]

Re: Sony XBR-65X850E power supply board diode replacement

Static vertical lines are damaged panels. Google Sony tcon training manual.

[nomoresonys]

Re: Sony XBR-65X850E power supply board diode replacement

maybe check the little capacitors on the panel driver board for shorts or very low ohms, right there in that area where you have the black stripe, it is a big bar, could try the tape cut off method, might not work but won't hurt to try, maybe check diodes/diode packs and other components on those boards also.

[KYBOSH]

Thank you for this post here. One of the four 5150s was shorted. Ordered a set from Amazon ($6) and replaced all four the next day.
TV started right up.