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**SgtRock** · 11-08-2015, 08:23 PM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

As per suggestion by RetiredCaps, I made up an inverter tester and tested all 20 inverter outputs. They are all turn the lamp on just fine. Interesting thing! If I try to measure the voltage at the drain of either 11N60T 600V 11 Amp MOSFETs. It tries to blow my Fluke 87 DMM rated for 1000V. Just drives it haywire or shuts it down. I do not have enough experience to know if this is normal or not. Any Suggestions?
Cheers!

Attached Files

**SgtRock** · 11-09-2015, 11:06 AM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

--Unplugging all of the right side CCFLs make no change in the behavior, and the same for the left side. So here is what we have so far. Green standby light on mainboard comes on as soon a TV is pluged in, 5 seconts later the display lights up for a second and shuts down, then comes on and shuts down. After that one must push the power button twice to get it to repeat. Also all voltages a cable plugs are nominal and remain on as long as TV is plugged in. I am about put this on into storage, with cardboard taped over the front, utill I can come up with an idea. Please someone, anyone hellllp!!!!
Cheers!

**ReeceyBurger123** · 11-09-2015, 11:13 AM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

Do you have persistent 24v going to the inverter even after shutdown ?

**SgtRock** · 11-09-2015, 11:21 AM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

Dear Reecey:
--Yes, indeed I do. Thanks for the prompt response.
Cheers!

**ReeceyBurger123** · 11-09-2015, 11:26 AM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

Ok alright, now could you upload a picture of the inverter Pcb please cheers.

**SgtRock** · 11-09-2015, 11:48 AM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

Dear Reecy:
--Included are a picture of the master inverterboard with 3 close ups, plus one picture of the slave board. I bought an extra slave board for checking and for the extra inverters and silicon. Just let me know of anything else you need. Many, many thanks!
Cheers!

Attached Files

**tom66** · 11-09-2015, 11:58 AM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

Check the "BLON" pin voltage -- see if it drops off when the TV turns off.

**freakaftr8** · 11-09-2015, 12:03 PM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

Your green light is on telling me that your TV is operating is shut down after half an hour due to a non usage condition that set in the menu. The inverter is inherently shutting down due to a fault somewhere along the back right away. However you say you have tested all the output with the CCFL tester. That's fine and all but it doesn't tell me that there is some kind of imbalance between the balancing circuts. If one bulb is weaker than the others that will shut down your TV back lights right away. You hear any consistent buzzing noises on the slave or the master inverter louder than the other one?

**SgtRock** · 11-09-2015, 12:55 PM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

Dear Reecey & Freak:
--I can find no BLON. Pow-DB is at 5.00V and remains so when power button is pushed. Pow-TV is at 3.301V and remains so when power button is pushed. Power-Pro is at 3.012V and remains so when power button is pushed. Power-Sig is at 3.280V and drops to zero when the power button is pushed the first time. The second time the power button is pushed Power-Sig returns to 3.280V and the back light come on.
--Hold the phone! The backlight are now remaining on, and the TV has a beautiful HDMI 1080p pic. Indeed, I do not trust this. But I am leaving it on for the moment pending further advice.
Cheers!

**SgtRock** · 11-09-2015, 01:13 PM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

R and F:
--Here are a couple of examples of the picture. I did manage to get into the menu and change the backlight to 50% from the previous 70%, just in case that helps.
Cheers!

Attached Files

**SgtRock** · 11-09-2015, 03:33 PM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

R, F and T:
--I left it off long enough for the green light to go out, a couple of times, and it starts back up with no problem. It comes on with the backlights at max and drops to 50% after about a half second. I am guessing that Freak is correct and that there is an imbalance. I will return it to the owner, and see what happens. If it fails again, with the backlights set to 50%, I will dissassemble all the way, and have a look at CCFL tubes. Unless there are any other ideas at this time. Again many thanks to Reecey, Freak and Tom. As a famous Ozzie said "It bites a pike in the eye, might."
Cheers!

**ReeceyBurger123** · 11-09-2015, 04:10 PM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

Nice one

I would suggest you test it before sending it back. All tvs I sell and repair I stress test for 24 hours.

**SgtRock** · 11-09-2015, 04:16 PM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

R:
--Good advice, I'll take it. I am just getting her zipped up right now. I will use it as a extra large second monitor until the owner shows up.
Cheers!

**ReeceyBurger123** · 11-09-2015, 04:40 PM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

Originally posted by SgtRock View Post

R:
--Good advice, I'll take it. I am just getting her zipped up right now. I will use it as a extra large second monitor until the owner shows up.
Cheers!

Cool beans, always best to do and power cycle it often.

**retiredcaps** · 11-10-2015, 01:47 AM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

Originally posted by SgtRock View Post

If I try to measure the voltage at the drain of either 11N60T 600V 11 Amp MOSFETs. It tries to blow my Fluke 87 DMM rated for 1000V. Just drives it haywire or shuts it down. I do not have enough experience to know if this is normal or not.

The highest voltage I have measured is 400V DC and Fluke meter worked with no problem. The Fluke 87 should measure 600V with no problem.

That mosfet, Q820, is on the hot side. Did you use the negative leg of the large filter capacitor as ground when taking a voltage reading?

**SgtRock** · 11-10-2015, 02:40 AM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

Dear RC:
--As I recall, I held one lead on the Drain and probed some points which I guessed might be the neg leg. I guess you could say I was just blundering around like a d***ned fool, grasping at straws. Unfortunately, the TV is all back together now and I do not really have the time to take it apart again. If there was some way to get an overvoltage, that is no doubt what I did. When I was in the Air Force a senior NCO once told me that if I was locked, naked, in a rubber room with two ball bearings, that I would lose one and break the other one.
--I often read up on your troubleshooting advice before starting a repair, and it has saved me from doing even more ignorant things, more than once. I include a few more pictures I took previously. Thanks mucho for you interest.
Cheers

Attached Files

**freakaftr8** · 11-10-2015, 02:49 AM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

Interesting glad it's working. My guess would be all the moving around you have done with the inverter board connecting them and disconnecting them from the CCFL tube connectors may have cleaned some carbon deposit on one of the connectors causing the CCFL to make contact with the inverter board. This may have fixed it and also the problem may have creeped up again.

**SgtRock** · 11-10-2015, 03:25 AM

Re: Toshiba Rezga 42RV530U 2 Seconds to Black.

Dear Freak:
--Yeah, I would agree. I also resoldered some iffy looking joints on the PS board when I had it out. I have had it running continously for about 8 hours now, and have turned it off and on many times, so far no problems. Also by turning the CCFLs down to 50%, the differences in the inverter xfmr voltages should have been lessened somewhat. But you are correct, It probably cannot be trusted, and that Is why I have asked the owner to come and get, so he can try to break it again. Whereupon I will personally inspect the lamps themselves and report back. I noticed that reducing the CCLLs to 50%, still left the brightness just fine for anything but full sun. I also reduce LEDs in LEDTVs to 50% to try and get extended life out of these old clunkers and curb queens that I repair for myself, friends and family, like the Vizio 32" RazorLED I am using for a monitor.
--I noticed the the Toshiba Regza 42RV530U is very well built and uses good 105C jappers everywhere. I just scrapped a couple of Polaroids, 32" and 40" from the same era 2007/2008 as the Toshiba. One look at the inside of the Roids convinced me junk them. Really outdated construction tech, with crap no name caps everywhere. I include some pictures from the Polaroid TDA-03211C 2007, which would come on but had a intermittent display problems like way too bright and washed out, definitely not worth my time. I did not disassemble the Polaroid 4011-2LXB also from 2007, which had a broken screen but I could see that the construction is just like the 32", I.E. the Mainboard and the PS board are both in a square metal fruitcake pan which rattles around loosly under the back cover. If any one wants any of the parts from these two I will be glad to send them to you for the most economical cost of shipping, usually USPS Parcel Select or Expedited. If no word in the next 24Hrs, to the nacker they go, RIP. P.S. I have a remote for the 4011-2LXB.