Toshiba Projection tp55g90 Dead

SOURCE: toshiba TP61E80 blows fuse

Blows AC fuse on plug-in is a direct short in power supply...
check components with ohmmeter to find short....Check MOV
across AC line by measuring across AC fuse clip.......T.

SOURCE: Toshiba 57H81 Flashing Red Power Light, Blown Fused F850+F852

Solved by resoldering some solder joints!!!!!!!
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Toshiba Model 57H81 Rear Projection TV - Purchased 11-09-2001

Problem: Toshiba 57H81 Flashing Red Power Light, No Picture/Sound, Blown Fuses F850 + F852

Symptoms January, 2009:

• Upon turning on set I got flashing red power light and nothing else.
• Removing plug for one minute and plugging in results in:
• Audible click, steady red power light for 2 seconds then slow flashing red light
• Pushing power button results in steady red for about 2 seconds then slow flashing red light, no other set activity
• Removing power cord for several hours and plugging back in made no change
• Audible click, steady red for about 2 seconds then slow flashing red light
• Possible related note: Over past several months occasionally the entire screen would flicker momentarily and at other times be problem free for weeks.
• Fuses F850 and F852 found blown

• PD0074 DEF/CON Power Board
• There are two main power supply capacitors in this set. They are C-809 and C-810. One their negative lead on the printed circuit board re-soldered leads and nearby contacts. I’m told that because the factory left out a printed circuit board eyelet, the connection will come loose over time. When I called Toshiba customer service they said there was a known solder joint problem causing blinking red light.
• Replaced blown fuses F850 and F852.
• I actually installed a fuse panel on the inside of the cabinet and routed the fuse connections here instead of ordering the special fuses and replacing them on the circuit board.
• Had to use a 5 Amp SLO-BLOW for F850. Fast blow does not survive power up. Get the red blinking light.
• Used a fast blow 2 Amp for F852.
• PD0073 SIGNAL Board
• Re-soldered Q751 + Q752 STK392-110 Convergence Amps
• Re-soldered adjacent pads that looks suspicious

• Twelve hours of my time over three days to research issue, disassemble set, make repairs, add fuse panel.
• Already owned Service Manual and Circuit diagrams from a different 2004 repair.
• Less than ten dollars at Radio Shack for fuses and fuse panel. Already had wires, etc.
• Some solder. Already owned de-soldering tools, etc.
• Visited both local authorized Toshiba factory service repair facilities. One said repair would have to include replacing Q751 + Q752 STK392-110 Convergence Amps with ST392-180, and realigning set for a total of $500+ and it would be more if they had to order a power board. NO THANK YOU! Other shop said $65 for site visit and $30 to make an estimate that could be applied to repair.

SOURCE: Toshiba 42

Hello,

This is not a bad tube it is a convergence problem. Your convergence amplifiers are malfunctioning, and need to be replaced. If you have a background in electronics, you can remove the back of the TV locate the Convergence ICs (using the schematic or service manual) and the order the parts you will need which are the two convergence ICs and the biasing resistors (you will see these on the schematic). To remove them unsolder the pins, unscrew the screws holding them on the heat sink and remove them carefully, if they stick use a solvent to break down the adhesion of the heat sink paste. Once loose, take them out and then unsolder the biasing resistors and replace them with the ones you ordered along with the ICs.

To install the new ICs put heat sink paste on the back of the ICs and insert the pins into the proper holes in the circuit board. Screw the screws back in securely, and solder the connections back.

After doing this you will need to perform a convergence adjustment, using the cross hair adjustment screen (access this from your TV menu). and the you will need to do an advance adjustment using the crosshatch pattern (also accessed from your TV menu).

Once these are done use you service manual to follow the procedures on locking the adjustments into the TVs memory.

I hope this helps,

Thank you,

Shuttle83,

http://www.electron-age-technologies-llc.com

SOURCE: Toshiba TP48C90 Convergence (replaced ICs, worked for 2 days)

Well, my thought is that there are a ton of knock off generic convergence IC's out there that usually hold up as long as yours did. Professionals like me will only use Sanyo original STK's. The counterfeit STK's out there are everywhere. Do some research on the web to locate Sanyo originals, they are out there.

Sonny Berry

• 8617 Answers
• Posted on Jun 20, 2009

SOURCE: I have a toshiba tz50v51 projection tv. the red power light is on

It could either be due to the convergence Circuits ( If the Power Indicator Blinks) or the power deflection board if it doesnt blink. I have a source for parts if you would like the link.