Toshiba 42HL196 repair

[budm]

Just fix this model which has red blinking LED, I tested the power supply board by itself first to see if all the output voltages are correct by using two 1K resistors to force on the power supply. When I applied the power to the board, I verified that the PFC Voltage booster circuit is working or not, it is putting out about 380~390VDC so I know that section is OK, but the 12V relay is clicking ON and OFF, that means the 12V power supply section is not staying on, I check and replaced the start up cap with no success, so I replace the SMPS IC Q880, after that, the 12V relay stops cycling on and off, the 12V out put is now steady with the small lamp as a load. Put the power supply back in, the TV starts up find after self test (blinking red LED) is finished. Q880 does run warm.
More pictures here:
http://s807.photobucket.com/user/bud...?sort=3&page=1

[MEB]

Re: Toshiba 42HL196 repair

Got one of these from the recycle center. The back cover had a hole in it and one of the boards was broken, but it was cheap. I didn't hear any glass rattling around so what the heck. I took the back off and the only real damage so far was the broken board. It was the Low B from the manual. I found 1 for 13 bucks on ebay. When I got the board, I replaced it and fired her up. I had the 3 red blinks which everyone here seemed to get so I broke down and bought and replaced Q820, Q860 and Q880 like most posts seemed to suggest. Now when I tried it out after replacing those parts, I get no red LED, but I get the relay clicking like budm described in this post. So I think I will attempt to remove the board and do what he suggested in this post to troubleshoot the board. I am going to take some pictures and will be back, but if anyone wants to chime in with the limited information I have given so far, be my guest. I haven't worked on many TVs, but this one is better than I have at home so I have high hopes. Thanks.

[MEB]

Re: Toshiba 42HL196 repair

Hello, Here are photos of the LowB board where it seems probable where the problem lies. I am going to try to fire it up for further troubleshooting as budm did above. If I don't blow something up, I will report back with hopefully more information. Thanks.

[MEB]

Re: Toshiba 42HL196 repair

OK, I hooked up the board like budm showed and it is trying to run. I don't know much about electronics but am trying to follow page 3 of the schematics for the PE0071 power supply board.

I believe it is relay SR80 on the board that is doing the clicking. It does so repeatedly every .5 seconds. If I put the meter on the 5V and Gnd at PB809B where budm had me put in those resistors, the meter cycles between 0V and 5V DC correlating to the clicks of the relay. He checked PFC voltage booster circuit. If I am on the right spot (across C821) I only get 160 VDC. At Q820 which I had replaced I get 0V at pin7 and a cycling 0-2.1 VDC at pin6going up and down in sync with the relay clicking.

I will be going back in to try to do more, but I really could use some guidance at this point. This is where I normally get into trouble as I don't know what I am doing.

[Andrew F. Ali]

Re: Toshiba 42HL196 repair

Good job budm!! That's what we talking 'bout.....component repairs...
Thanks

[MEB]

Re: Toshiba 42HL196 repair

At the suggestion of another I am moving this to a new thread.

[Rome]

Re: Toshiba 42HL196 repair

Just fix this model which has red blinking LED, I tested the power supply board by itself first to see if all the output voltages are correct by using two 1K resistors to force on the power supply. When I applied the power to the board, I verified that the PFC Voltage booster circuit is working or not, it is putting out about 380~390VDC so I know that section is OK, but the 12V relay is clicking ON and OFF, that means the 12V power supply section is not staying on, I check and replaced the start up cap with no success, so I replace the SMPS IC Q880, after that, the 12V relay stops cycling on and off, the 12V out put is now steady with the small lamp as a load. Put the power supply back in, the TV starts up find after self test (blinking red LED) is finished. Q880 does run warm.
More pictures here:
http://s807.photobucket.com/user/bud...?sort=3&page=1

Budm, where did you get your service manual, I bought one but not like yours my model # 42RV530U thanks anyway.

[budm]

Re: Toshiba 42HL196 repair

ELEKTROTANYA.COM
http://elektrotanya.com/?q=showresul...oria=&kat2=all

http://elektrotanya.com/?q=showresul...oria=&kat2=all

[logon bump]

Re: Toshiba 42HL196 repair

Wow, that site has already taken down that link or something else, because only one of those docs is available now.

[jts1957]

Re: Toshiba 42HL196 repair

Wow, that site has already taken down that link or something else, because only one of those docs is available now.

From one who uses that site all the time, ALL appears to be there once you 'GET MANUAL' and unzip the resulting.
PDFs allow preview ... Zips DO NOT allow a preview.

[CraigR]

Re: Toshiba 42HL196 repair

budm, would you have a part number for Q880 and where you bought one? I have the exact same results you did.