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
AWESOME - I'm so happy for

AWESOME - I'm so happy for you. I think you found the problem.

toshiba 57h94
toshiba 57h94's picture
got free t.v out of garbage

got free t.v out of garbage.owners thought is was power supply but red light turns on can hear power to tv but can't see or hear nothing.took apart everything looks in good shape.would there be away to get a manual for a toshiba 57h94 the owners didn't have it no more

tvindivo
tvindivo's picture
We've had a Toshiba 57H81 for

We've had a Toshiba 57H81 for over 8 years, never a problem. Yesterday morning went to turn it on and got red power light flashing and no sound or picture. I don't have any technical education or experience. Can you help me?

ricknjen@charter.net

TommyTester
TommyTester's picture
Sandino - rickjnjen -

Sandino - rickjnjen - Unfortunately this repair is beyond anyone having little or no technical eduation or experience. Most likely the root cause issue is the bad power supply capacitor solder joints that create collateral damage of blowing fuses. You could call Toshiba or search their we site to find an authorized service center. By now they should be pretty familiar with this. Unfortunately you will probably be out $500+. Might be time for a new set.

Toshiba 57h94 - I don't have anything on this set. Sorry.

tvindivo
tvindivo's picture
Hey Tommy,

Hey Tommy,

We bought the Toshiba 57H81 from Best Buy in 2001 so I called them for service. They use the Geek Squad. As you warned, they suspected the power supply board and estimated about $550.00 to repair. I tried to get a power supply board from Toshiba but they don't sell direct. They directed me to Fox International 800-321-6993. Unfortunately they only sell OEM parts and the power supply board is NLA. I believe I could make the repairs if I had a repair manual. Would you mind sending me a copy of the repair manual? (ricknjen@charter.net)

Thanks for your help
Sandino

TommyTester
TommyTester's picture
Sandino, I have seen those

Sandino, I have seen those power supply boards from time to time on eBay as people part out sets. You might look there. I will send you what I have.

Good luck,
Tommy Tester

tomg
tomg's picture
Thank you. This is a great

Thank you. This is a great link. A good friend upgraded to a new TV and gave me his old Toshiba Model 57H81 Rear Projection TV. It still worked fine at his house, but after moving it across town in a truck, it has the Flashing Red Power Light, No Picture/Sound issue that was described in the posting. If possible please send me any technical information you have. I may be able to fix this with the information already supplied, but schematics and wiring diagrams would sure be helpful. Email: wtgregory@comcast.net
Thanks.

TommyTester
TommyTester's picture
tomg - I sent you four emails

tomg - I sent you four emails with the files you should need. Again this is not cookbook but if you have good electronic skills you should have what you need. Please report back on here when/if you are succesful. What out for the high voltage sections and MERRY CHRISTMAS.
Tommy Tester... Mine is still working but I now has an annoying tri color triangle of dots in the middle of my screen. I just put up with it.

jimpet
jimpet's picture
Hi Tommy,

Hi Tommy,
I have the same red blinking light no video or audio problem with mt 57H81 could you please email service manual to jimpet@princeton.edu.
Merry Christmas! Thanks So Much!
Jim

TommyTester
TommyTester's picture
Jim, I just sent you four

Jim, I just sent you four emails. Good luck and please post your results. My set is still working. Merry Christmas. Tommy Tester

TommyTester
TommyTester's picture
I remoted the fuses so you

I remoted the fuses so you wouldn't have to go back into the set.

jimpet
jimpet's picture
Thanks for everything, I have

Thanks for everything, I have not yet studied the info or opened the set because I am busy being Santa.
Are the fuses accessed from the front or the back?
Happy Holidays!

TommyTester
TommyTester's picture
Fuses are soldered into the

Fuses are soldered into the circuit board. you must remove the circuit board to get to them. :-(

KyleY
KyleY's picture
Having the Red LED blink

Having the Red LED blink issue with my 57HX81 set. Have begun to disassemble the unit to check for faults (quite a task...). Any chance I could get a hold of the service manual for this set from someone? It would be a great help in getting this old girl humming again.

kyle dot yencha at gmail dot com

Thanks!

KyleY
KyleY's picture
Having the Red LED blink

Having the Red LED blink issue with my 57HX81 set. Have begun to disassemble the unit to check for faults (quite a task...). Any chance I could get a hold of the service manual for this set from someone? It would be a great help in getting this old girl humming again.

kyle dot yencha at gmail dot com

Thanks!

jimpet
jimpet's picture
WOW! FANTASTIC!

WOW! FANTASTIC!
Tommy you are the MAN!
I disassembled my 57H81 and found F850, F851 and F852 were blown. I removed them from the C.B. and replaced them with two 5A and one 2A slow blow inline fuses from Radio Shack.
Cost for solder iron and parts was $27.00.

I am a 30 year electrician with minimal electronics experience so I was fairly confident that I could accomplish the task but doubtful that it would be a successful result.
About six hours later VIOLA! my baby is alive but snow screen so my skepticism creeps in until I hookup cable and the right input and channel on the TV and then there is the beautiful Oprah looking right at and talking to me.

I actually am not an Oprah fan but I was so thrilled to see her and have the set back with just pocket change and swelled pride.

This set is used by the kids in a garage apartment and I also have a 57HDX82 in the house so good thing that I am now a Toshiba Tech.

Very exciting and gratifying!
Thanks So Much Tommy,
Jim

sh3khar
sh3khar's picture
Tommy, thanks for the great

Tommy, thanks for the great information!

I have a 57HDX82 with a very similar problem:
No picture / no sound, BUT the red power light stays ON (does not blink).

The hyperboard was replaced on this TV about 4 years ago due to the wavy lines issue - everything was good after that.

Then, 2 years ago, this TV developed the convergence problem and I replaced both the STK392-110's with STK392-180's - everything was great after the fix.

Now, I turned on the TV - red power light comes on and stays on, but no picture and no sound. Anyone else have this issue? Wonder, if this symptom is also the result of C809 / C810 bad connections along with blown F850/1/2 fuses?

Could you please email me any information you may have to:
sh3khar (at) yahoo dot com.

Thank you very much! This thread was VERY helpful!

Skip C
Skip C's picture
Tommy, You are probably

Tommy, You are probably getting tired of hearing this, but would you send me the service manual as well? My boss gave me this TV and I have the blinking red light issue.

Thanks!
Skip
fixenplanes at yahoo dot com

TommyTester
TommyTester's picture
Skip & Sh3khar - Just sent

Skip & Sh3khar - Just sent each of you 4 emails

Skip (Fixenplanes) - Here is first of four for 57H81 - Good luck to you

Sh3khar (57HDX82) - Steady Red - No picture / No Sound.
1) Not sure if the 57H81 material I'm sending you will directly apply
2) Doesn't sound like the exact problem. The flashing light is supposed to indicate failed power supply and yours is steady on. Can't offer you any additional other than search the net for your steady red light

Good luck to all. If you have success please post it on Techlore

Happy New Year
Tommy Tester (aka private pilot)

jlretz84
jlretz84's picture
Hi there,

Hi there,

I just found this thread, as I am having the same problems on my Toshiba TV. Is there any way you could also send me the manual? My email is jlretz84@hotmail.com. I can send/receive files up to 25MB.

Thanks,
Jason

jimpet
jimpet's picture
Tommy,

Tommy,
Unfortunately my set has the blinking red light again after working fine for a few days. F850 continues to blow but F851 and F852 are not blown and there does not appear to be any obvious bad solder joints...My PCB does have the C809 and C810 eyelets but I added solder anyway.
I would appreciate your expert advice as I am still determined to fix this problem.
Thanks Again,
Jim

TommyTester
TommyTester's picture
Jim - I probably should have

Jim - I probably should have added that not only did I resolder C809 and C810, but I also soldered wires going from the C809 / C810 pins to the circuit paths both upstream and downstream from the capacitors. I forgot all about that. My first fix (without the jumper wires) lasted about six months. Then I added the jumper wires and it has worked a few years now. That is what I would do. Sorry I didn't mention that before. Let me know. Good luck.
Tommmy Tester

moosettner
moosettner's picture
Hi Tommy, My mom just called

Hi Tommy, My mom just called, says her Toshiba back projection TV just made a loud pop and now the screen is black, sound is intermittent (clear for 1 minute, then no sound for 30 seconds, repeating), red light flashing. Would be interested in your files as well if you don't mind and any thoughts. Thanks, Moose

TommyTester
TommyTester's picture
Moose, I have never heard of

Moose, I have never heard of the symptoms you are describing: sound is intermittent (clear for 1 minute, then no sound for 30 seconds, repeating), red light flashing. Normally set it dead with red flashing light. If you provide email address I will what I have. If you wish you can send your email in a private message. Good luck
Tommy

moosettner
moosettner's picture
Tommy, Sorry, Actually my mom

Tommy, Sorry, Actually my mom was looking at her cable box when she said there was a red light flashing. The TV LED's are actually erratically flashing. Orange on a slow period and green on a rapid flash. When the orange is on (and green flashing) there is sound. When orange is off, no sound. Always no picture. Is this in your realm of experience?

LisaR
LisaR's picture
Hi Tommy,

Hi Tommy,

could you please send me the service manual for 57h81 also. Having the same problems I see everyone else has. Thanks.

reeve@bloomer.net

TommyTester
TommyTester's picture
moosettner - I'm sorry but I

moosettner - I'm sorry but I don't have anything else to offer. Tommmy Tester

TommyTester
TommyTester's picture
LisaR - Four emails sent.

LisaR - Four emails sent. Let us know on the forum if you are successful. Good Luck. Tommy Tester

dwalkinking
dwalkinking's picture
Hey tommy tester can you

Hey tommy tester can you email me the service manual be real helpful
thanx
dwalkerpeters@gmail.com

dwalkinking
dwalkinking's picture
hey tommy could you send me

hey tommy could you send me the service manual to the 57h81 it would be greatly healpful

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