OUR NETWORK: TiVo Community Explore3DTV My Open Router DVRplayground MediaSmart Home See all... About UsAdvertiseContact Us

 
Learn about scoring Forum's Raw Score: 4260480.0
January 3, 2009 05:52 PM

Categories: Televisions and Projectors

Rating (0 votes)
  • 1
  • 2
  • 3
  • 4
  • 5
Rate This!

Member Avatar

TommyTester

Member
Joined: 01/03/2009

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.

Discussion:    Comments 1-25 of 76 | Latest Comment | 1 2 3 4 Next »

May 22, 2009 11:39 AM

The jumpers on my board are not numbered is a picture available to show the location of jumper 010?

View unverified member's comment - posted by Steve T

Answers Post December 6, 2009 7:40 AM

Glad it worked out for you. Mine is still working! :-)

View unverified member's comment - posted by Simon XTP

March 25, 2010 10:11 AM

If you can get me an email address I can email you the service manual. It has the board layouts and parts ID

March 28, 2010 9:26 PM

Dear Tommy Tester, Thank you for ypur reply Here the email adress to send me the Manual in order to help me to find the right part to fix (please tell me what is the page I should look at)

have a nice day

Simon

April 7, 2010 5:13 PM

jrh at binarydesigninc dot com

Tommy Tester, would you be willing to send the manual to me as well. My TV just started exhibiting the behaviors described above and $10 sounds much better than the replacement cost.

Thanks,

James

May 2, 2010 2:56 PM

Simon + James: Check your email. Good luck. My set it still working. Tom

June 11, 2010 8:56 PM

Came across the same problem and noticed the thread was kind of recent. Would you mind send the service manual as well? Thanks.

jedijoel at gmail

June 20, 2010 5:18 PM

Hey Tommie, I was wondring if you can email me the service manual for the 57h81!! Ifound a free tv and wanted to do the repairs my self! Just can find all the fuses i am looking for! Thanx if you can help!! jrmdncnhns@yahoo.com

June 24, 2010 4:21 AM

jrmdncnhns@yahoo.com; jedijoel@gmail.com

please check your email... good luck

one file was 10MB, hope your email service accepted it

View unverified member's comment - posted by tvfixxer

View unverified member's comment - posted by marino

July 20, 2010 3:28 PM

I got you Marino. There are 3 messages one is 10mb but gmail should handle it. Share the love, right!

September 16, 2010 1:33 AM

I have a 65H81 and the same problem with the blinking red light listed above. Would your manual that you have be of use to me? If so can you send it to my email address cowboyup2332@yahoo ? Thanks!

October 9, 2010 9:45 PM

Hey,I'm struggling with the same flashing red light and trying to fix it myself. Would you mind sending another manual for the 57H81?

Thanks,
Dave
daveandjeramie@hotmail.com

October 9, 2010 9:47 PM updated: October 9, 2010 9:52 PM

Any thoughts on blown fuses or loose connections? I have checked them while on the board and they don't appear to be blown. Probably I have the loose connection problems, but I have already tried to resolder 809 and 810 with no change. Still getting the flashing red light.

October 10, 2010 8:10 PM

Dave,
I have emailed you the files. Good luck.
Tom

October 13, 2010 2:40 PM

I have a blinking red light on a Toshiba 50hpx95.. Would this be the same issue, fuses etc???

If so could you also email me the guide to collirg@gmail.com

October 13, 2010 9:03 PM

I don't know about the 50hpx95. Would suggest you call Toshiba's 800# and see if this 50hpx95 has a known service bulletin on it like my set has.

My documents won't help you unless you have the same power supply board as mine. That being said I will send you what I have but they might not help you.

Tom

October 14, 2010 6:52 PM

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 rpolzin1@new.rr.com

October 16, 2010 9:19 PM

rjp - good luck, check your email. Just sent it. Please post your success, or not.

October 18, 2010 7:56 AM

replaced fuse f850 only one that was blown TV worked for 1/2 hour than blow out fuse and keeps blowing it out. Just need to do my homework thanks for all the information I will let you know when i seccede

View unverified member's comment - posted by will free

October 23, 2010 7:52 AM

will free - This job is not for the faint of heart. I am a retired Electrical Engineer. There is not repair manual. I respectively submit that this job may beyond what you should attempt and could also be risky around the high voltage sections. There is no Repair Manual. Please be careful. Tommy

Discussion:    Back to Top | Comments 1-25 of 76 | Latest Comment | 1 2 3 4 Next »

Thread is locked, no more posts may be added.

 
 

Please log in or register to participate in this community!

Log In

Remember

Not a member? Sign up!

Did you forget your password?

You can also log in using OpenID.

close this window
close this window