Sony KDL46V5100

[dbier63]

Set powers on for a few seconds and then powers off. I checked the diagnostic menu and found the backlight menu has 6 errors. Can anyone help with what this may be?
Thanks in advance.

[budm]

Re: Sony KDL46V5100

Please upload good clear pictures of the whole back side of the TV so we can see how all the boards are connected together, that will be a start.

[budm]

Re: Sony KDL46V5100

Check the DCV on the VCC pin, FB pin (set meter to AC on this one), and LD pin on the connector CN6701 of the POWER SUPPLY-inverter board when TV is turned on.
BTW, did you see the backlights even flash on for seconds before error loght comes on? You may have to at it in the darkened room.

[dbier63]

Re: Sony KDL46V5100

I will check this tomorrow. Thank you

[dbier63]

Re: Sony KDL46V5100

Checked DCV on VCC pin. It reads 11.91 VDC. Pin FB and LD with meter set on AC readout briefly flashes for a split second then drops right off. Can hear a faint click like a relay dropping out. By the way the screen did actually come on one time when I pressed the power and menu buttons at the same time but, only stayed on for a couple seconds. Also I have changed T-con board but did not help.
Uploaded some pictures.

[dbier63]

Re: Sony KDL46V5100

Also the backlight did flash briefly in a darkened room.

[budm]

Re: Sony KDL46V5100

LD pin is needed to be checked in DC mode, only the FB is checked in AC mode.

[dbier63]

Re: Sony KDL46V5100

Ok thanks I pulled the board and found one bad cap. C6250 was found open. Also found 3 power diodes below .2 vdc so I'm assuming they are bad as well. Once I get the board repaired I'll check those voyages again and get back to you.
Thanks a lot.

[dbier63]

Re: Sony KDL46V5100

readings are pin LD 11.37 VDC
FB 2.4 mVac
What do you think?

[budm]

Re: Sony KDL46V5100

LD (Lamp detect) signal is good (>11V = Good).
You get the FB because there were high Voltage present shortly and but then it drops drops out but not due to bad lamps. So some how the inverter circuit has dropped out and that is why you get 6-blink error for inverter error.

[dbier63]

Re: Sony KDL46V5100

Did some more checks. wire bundle going to main board as follows:
reg 12v 11.97 vdc
reg -12v 0 vdc
reg 15v 0 vdc there are 3 wires for this one reads 1.2vdc until relay switches then goes to zero.
reg -15v 3 wires .6, .6, 0 vdc
stby 3.4 vdc
ac off 3.5 vdc
on 3.3 vdc

Power to T-con
reg 12v 2 wires 11.97 vdc
reg -12v 2 wires 0.0 vdc
Please help
Thanks

[dbier63]

Re: Sony KDL46V5100

These are all readings from PS board

[dbier63]

Re: Sony KDL46V5100

I'll let you digest the last readings but do you think maybe it could be bad inverter board? It's the only board I haven't removed the cover on and physically looked at.

[budm]

Re: Sony KDL46V5100

What are the REG-12, and REG-15? Is that how the pins are labeled?
With 6-blink error, I would look into the Inverter section at this point.

[budm]

Re: Sony KDL46V5100

You have the power supply-inverter board combo, it the big board (IP2) in the middle of the chassis with big grey inverter transformer on the top left corner.

[dbier63]

Re: Sony KDL46V5100

labeled unreg -15 and unreg -15_gnd
the other one is reg12_gnd

[budm]

Re: Sony KDL46V5100

Service manual:

[dbier63]

Re: Sony KDL46V5100

yes thats the board. here's some pics.

[budm]

Re: Sony KDL46V5100

So you are not getting the Unregulated -15V output. Need to look at the diagram in the service manual next for that Unreg -15V power supply to see how it is generated and what it is used for.
You do have 12V to run the T-CON board.

[dbier63]

Re: Sony KDL46V5100

Thank you bud. Are you thinking the inverter transformer may be bad?