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

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

 

Repairs Made:

  • 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

 

Total Cost to Repair about $10

  • 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.

 

***************************************

HISTORY + RESEARCH

  • Could not have done this without the wonderful internet and various forums and blogs.
  • I did locate a link to what I believe is the Toshiba Service Bulletin but I could not access it without a Toshiba tech ID/PASSWORD.  Did not find the Service Bulletin  posted online; that surprised me.  Here is what I believe to be the Service Bulletin link.
  • I have an Electrical Engineering degree but have really been an IT person the last 25+ years. However the training and past experience from the 70s helped me out.
  • Previous Repair December, 2004 – So I had already torn the set apart once
    • Symptom: was intermittent ghosting in only a few video modes
    • Solution: Replaced TA1316AN  Signal/Sync Processor(Q510) on PD0073 Signal Board
    • Set professionally converged and color set by certified technician
  • Summary of reading all the FORUMS and BLOGS Google could find
    • MOST posts suggested the problem is caused by faulty Q751 / Q752 STK392-110 convergence amplifiers.  This wasn’t my problem.
      • These posts typically say to also check your low ohm resisters associated with the amps.
      • Seems to be some controversy whether to replace the STK392-110 with STK392-180.  They from who – SANYO?  One Toshiba repair shop does this. The other one says you must use the original Toshiba STK392-110. Who is right? I didn’t need to make the decision but I did a lot of research and was leaning towards authentic SANYO parts or the Toshiba  STK392-110 from www.partstore.com but these were about $40 EACH.
    • The most helpful posts were those that pointed me towards re-soldering a number of connections.  Since I re-soldered connections on BOTH the PD0073 Signal Board and the PD0074 DEF/CON power board I don’t know for certain which board had the fault – sorry but I am happy with the result!
    • Cold Solder Joint helpful forum / blog entries
      • Very common problem. There is a Toshiba service bulletin out on this. Look for F860, if it is blown, do not replace it till you pull out the chassis and look in the main power supply for the two large capacitors, C809 and C810. They may have bad connections on the negative connections due to the printed circuit board eyelet being left out of the set. I have repaired many of these sets and once after another tech wanted to charge the customer 600 bucks! Just be very careful when working on this TV set. Good Luck
      • Found problem to be blown fuses on the power board caused by bad solder connections.  Re-soldered the bad connections and replaced fuses F850, F851, and F852.  Think it was links 010 and 050 – found the bad connection by tracing back from the blown fuses and checking each joint.
      • If fuse F850, F851, or F852 are blown check the following:  Check jumpers 010 and 050 for bad solder connections.  They are located near the left edge of the signal PCB near the convergence amps.  Check the connections on either side of the wire under or along the edge of the chassis frame.  I was faced with this problem and Toshiba recommended this fix and I did find bad connections and I haven’t had the set back again.
      • I found 3 open fuses in power supply caused by a bad connection at Jumper 010 in front of the L7711 in front of the convergence ICs.  Also check all other jumpers in the area.  The fuses F850 are 5 amp part #23144842 and F852 is a 2 Amp #23144841.  (NOTE: I substituted a SLO-BLOW 5 amp fuse for F850 and a fast blow 2 amp for F852).
      • Toshiba 53H71.  Had a convergence problem about ten months ago and replaced the Q751/Q752 (STK392-110) convergence ICs and tv worked fine.  Now customer called and tv is dead. I went there and found that F850, F851, and F852 were bad. Replaced them and they blew again.  Then found that one of the new STK392-110 had pin 8 shorted to ground.  The fix I got was “re-solder jumper wire L7711”, on my set jumper above L7711 was the bad one. Replaced the three fuses and set is still running fine.
      • As for fuse F850 blowing check jumper 010 and 050 loose or broken.
      • This one came in with fuses F851 & F852 on the convergence output supplies blown. Found a bad connection on the black jumper near BB20, the white connector between the deflection board and signal board.
    • Bad STK392-110 Convergence IC  helpful forum / blog entries
      • Most forums are dominated by replacement of these Q750/Q751 amps.  Indeed their failure for convergence seems to be rather common.
      • However the amps on my 57H81 that I’ve had since 2001 are still working OK.
      • It does appear from the blogs that a defective STK392-110 may cause the power supply fuse failures.
      • It would be most helpful if someone could post the Toshiba service bulletin - http://www.tacpservice.toshiba.com/TACP/training/module1/Mod1sg1.html
      • It does appear that you need to be careful in purchasing quality STK392 parts if you have to go that way.  You can get the real deal from www.partstore.com
    • Hope this helps. My fixed TV has been working for five hours now.  About the watch the Colts playoff game!  Good luck.
TommyTester
TommyTester's picture
dwalkinking - 4 emails sent.

dwalkinking - 4 emails sent. Let us know if you are successful. Tommy Tester

TommyTester
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Evil (Moderator) - If you

Evil (Moderator) - If you want to send me your email I will forward CD, Board Layouts, etc and you can look it up. Blessings. Tommy

Buddyro
Buddyro's picture
Hi Tommy,

Hi Tommy,
Fixed my set 2 years ago using this info. After fixing it hd programming works perfect. But, when i use any other picture soure on the tv i get two thin verticle lines on the screen that are equally spaced. the tv plays the program, but these lines are super imposed over the picture dividing the screen into three sections. there are also some horizontal lines in the picture too. This happens after the set has been on approx. 30 min. and of course not using the hd1 picture source. Is it possible that a wire or something was placed to close to a heat source after the repair and is causing this problem?
Dash

TommyTester
TommyTester's picture
Dash (Buddyro): Unfortunately

Dash (Buddyro): Unfortunately I don't have any additional insight on that.

I had to repair my set twice. First repair lasted six months. The second time I added jumper wires to either side of C809 / C810 as the solder joints had to be resoldered. For the past few years I have been dealing with a perfect triangle of the three primary color dots in the middle of the screen. Set has been otherwise fine for quite some time. However in last six months the auto focus fails. Still putting up with set. Quality of picture matches by declining eyesight. LOL

Sorry I can't offer more on this.

manstoblame
manstoblame's picture
my looks like these

my looks like these projection sets all have the same general problems. I have the 42 inch Toshiba 42h83 and when changing out capacitors on hyper board something shorted I believe its a voltage regulator,and blew the out put transistor not sure. But would you have that service manual I need the schematics for the hyper module MVPU14 is that included in the 57h81 service docs if so would you help me too? by sending to manstoblame@gmail.com or manstoblame@yahoo.com any help you can offer is appreciated. Oh and by the way do mitsubichi and sony have similar parts to toshiba? probably a dumb question but thanks in advance anyway

TommyTester
TommyTester's picture
Manstoblame: Sorry but I don

Manstoblame: Sorry but I don't think my manuals have that MVPU14.
NEXT HYPER (Advanced HYPER Board)is included in the 50H81 Circuit Diagram.

Not trying to pass myself off as the expert on this Toshiba set. Just sharing the research and repairs that I made for a common problem (blinking red light) affecting many 50H81/57H81/65H81 sets. Sorry I can be more help. I have uploaded all my manuals to the TechLore Technicians Corner. They should be available for download soon. Sorry I can't be of more help. Good luck.

TommyTester
TommyTester's picture
Are you looking for the

Are you looking for the Toshiba manuals that I have emailed many in the past? I just uploaded them to the TECHLORE Technican's Corner (2-1-2011) and they should be posted for download in a few days.
Toshiba 50H81 Service Manual
Toshiba 57H81 Service Manual Supplement
Toshiba 50H81 (also 57H81 / 65H81) Circuit Diagrams
Toshiba 57H81 Disassembly Photos
Toshiba Rear Projection Digital Convergence Alignment Technical Training

TommyTester
TommyTester's picture
Good news for both you and me

Good news for both you and me! All of the service manuals, circuit diagrams, disassembly photos, etc have been updloaded to Technician's Corner. I will place the links here. As always please continue to share your experiences repairing the infamous Toshiba flashing red light problem.

Good luck! Tommy Tester

Here are the specific links:

http://www.techlore.com/download/31104/Toshiba-57H81-Digital-Convergence/
http://www.techlore.com/download/31103/Toshiba-57H81-Disassembly-Photos/
http://www.techlore.com/download/31102/Toshiba-50H81-Circuit-Diagrams/
http://www.techlore.com/download/31101/Toshiba-57H81-Service-Manual-Supp...
http://www.techlore.com/download/31100/Toshiba-50H81-Service-Manual/

The entire download section can be found at: http://www.techlore.com/group/2/list_downloads

GeneJohn
GeneJohn's picture
Does the PD0074 board need to

Does the PD0074 board need to be removed to correct blow fuses F850 an F852? If so what is the sequence for removing this board?
Gene

GeneJohn
GeneJohn's picture
Tommy Tester

Tommy Tester
On the Toshiba 57H81 how do you remove the PD0074 board to replace or rewire fuses F850 and F852?
Gene
p337gene@gmail.com

TommyTester
TommyTester's picture
Gene,

Gene,

Links to everything including disassembly pictures, etc are posted earlier in this thread. Please go back to the post dated

February 1, 2011 5:55 PM
and go from there.

Good luck,
Tommy

Pankaj Mody
Pankaj Mody's picture
I have problem with Toshiba

I have problem with Toshiba 57H81 Red light blink problem. Please send me the Toshiba manual which shows location of the fuses. My email ID is pymody@gmail.com

Pankaj Mody
Pankaj Mody's picture
I have the same blinking

I have the same blinking power light on my 57h81,have not opened up tv yet but being a petroleum tech. I sure with these insturctions I can fix the problem It would be great if you could send me the service manual it would be greatly appreciated modypy@gmail.com

TommyTester
TommyTester's picture
Links to everything including

Links to everything including disassembly pictures, circuit diagrams, etc are posted earlier in this thread. Please go back to the post dated

February 1, 2011 5:55 PM
and go from there.

Good luck,
Tommy

rwgage
rwgage's picture
I am having the similar power
I am having the similar power supply problem with my Toshiba 57H81 so I wanted to know if doing the soldering fix  stated fiuxes the problem. Namely replacing the C-809 and C-810 capacitors as well as fuses F-850 and f-852..    Thanks,   Robert
soyboy22
soyboy22's picture
Hi Tommy,
Hi Tommy, I'm having the same problem.  Please forward me anything you can so I can make the repair. Thanks, Scott.

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