Re: Sony KDL-19M4000 Dead

Thanks Bud. I got sidetracked with car repairs and plunbing repairs. Am now finally able to get back to the TV issue.

No, don't have an ESR meter. But I should probably buy or build one since there are a number of antique radios people want me to look at. (Any suggestions?)

In the meantime, I will replace those two startup caps.

I'll let you know how it works out.

Re: Sony KDL-19M4000 Dead

Thanks for the response, Tom. But that really wasn't an issue. I was just explaining why I measured to ground first, and then across the cap.

After thinking about the symptoms, particularly the varying voltages (see earlier post), I'm beginning to think this may be either an auto-shutdown problem, due to an overload on one of the supplies, or a kick-start issue. Of course without a schematic, the debug/analysis is that much harder.

Has anyone had any experiences with these types of problems?

Has anyone successfully...

Re: Sony KDL-19M4000 Dead

Thanks for the reply, Bud. (I've been on the road a few days.)

Yes. I just automatically measured the voltage to chassis ground. But once I saw the peak voltage across the cap, I knew I was on the line side of the circuit.

I tried the hair dryer idea per your directions, but no change -- still dead.

I also was attempting to trace that part of the circuit (and draw a schematic) from the foil side of the board. But it's rather involved.

Would appreciate any other ideas/approaches you might have...

Re: Sony KDL-19M4000 Dead

Thanks for the quick replies guys.

To Budm's questions --

Yes, that is the board.

Measuring C101 and C102, all leads to ground are zero. However across the leads of each cap, I read 159 Vdc.

Also. the voltages on CN101 are not exactly zero. There are --
on the 5.5v pins --> 1.5 to 2.0 vdc, varying
on the 2.5v pins --> 1.0 vdc
on the 12v pins --> 2.5 to 4.0 vdc, varying

I have a Sony KDL-19M4000 Flat Screen that is dead -- no standby light.

Fuse F101 checks good.

Got servioe manual. On power supply board (G boord) connector CN101 has no voltages present. Manual has pictorial/layout of G board, but states that schematic is not available.

Traced out some of board (Wow! Never saw so many filters and flash gaps.) and have continuity from line cord connector to BD101 (bridge rectifier??).

I'm flying blind here.

Is anyone familiar with this board? Or have an idea on how to approach this problem...

Re: New Members - please post your introductions here

Hi. This is unique, having to do an intro to a forum. But it is an interesting idea.

Since I am very sensitive about privacy, I won't say much -- just give some relevant info.

I have been involved with electronics since early teens -- designing, scratch building and kit building (starting with Knight Kit Walkies-Talkies, and a Heathkit Pawnee Transceiver). Also lots of repair work, and built many PCs.

I have both EE and CS degrees. My whole career has been as a software developer,...