Hi!..I had a question regarding F850 ad F851 in my Toshiba 42H81. These are 5A, 125V fuses. I want to purchase them locally if I can. Are these special types of fuses? Do I need to order the exact same manufacturer type? Any advice would be well appreciated...thanks!
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Solved by resoldering some solder joints!!!!!!!
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.
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.
www.partstore.com will have the fuses you need F850 and F851 are part number 23144627 125V 5.0A axial and F852 is part number 23144624 125V 2.0A axial just enter those part numbers in the search box for part number and they will have your fuses.
Pull chassis--check all fuses,esp, F850 & F851.They protect the B+ supplied to convergence circuit.They are found in the power supply,on edge of the main board.On the signal board,locate the large IC's mounted to heatsinks.IC part # STK392-110.Between the edge of the signal board and the IC's---locate two grey jumper wires and some hard wire jumpers = solder them all,if you don't,the fuse may blow again.Next,replace IC's with Hitachi up-grade part # STK394-160E....Reassemble...power on.....touch magic focus and you are done....T. ?????s-----Let me know...
Well without the schematic, knowing Toshiba they have alot of convergence problems, so see if the fuse blown in the convergence area, if you you may have to replace convergence amps. These are the big STK's. Most of the time there was a color problem with set before going out. If no problem with this on your set then look in the HV area Hor. and Ver. area. Hope this helps!
The place is call wwww.servicemanuals.net ,you can get it download or a paper copy,for this set I dont know the price but it will give it to you when you put the model number.Check for shorted horizontal output and loose conections,sometimes intermitant conection damage this transistor.Be careful