Home |
Search |
Today's Posts |
|
Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
Posted to sci.electronics.repair
|
|||
|
|||
Hitachi 37LD9000 Inverter tripping, Story in pictures
Hitachi 37LD9000 Inverter tripping, green led on, sound ok, no
picture. Pics contain textual narration. http://i596.photobucket.com/albums/t...o_2/Image1.jpg http://i596.photobucket.com/albums/t...o_2/Image2.jpg http://i596.photobucket.com/albums/t...o_2/Image3.jpg http://i596.photobucket.com/albums/t...o_2/Image4.jpg http://i596.photobucket.com/albums/t...o_2/Image5.jpg http://i596.photobucket.com/albums/t...o_2/Image6.jpg Jango |
#2
Posted to sci.electronics.repair
|
|||
|
|||
Hitachi 37LD9000 Inverter tripping, Story in pictures
On Nov 25, 10:10*pm, jango2 wrote:
Hitachi 37LD9000 Inverter tripping, green led on, sound ok, no picture. Pics contain textual narration. http://i596.photobucket.com/albums/t...o_2/Image6.jpg *Jango |
#3
Posted to sci.electronics.repair
|
|||
|
|||
Hitachi 37LD9000 Inverter tripping, Story in pictures
On Wed, 25 Nov 2009 22:10:44 -0800 (PST), jango2
wrote: Hitachi 37LD9000 Inverter tripping, green led on, sound ok, no picture. Pics contain textual narration. http://i596.photobucket.com/albums/t...o_2/Image1.jpg http://i596.photobucket.com/albums/t...o_2/Image2.jpg http://i596.photobucket.com/albums/t...o_2/Image3.jpg http://i596.photobucket.com/albums/t...o_2/Image4.jpg http://i596.photobucket.com/albums/t...o_2/Image5.jpg http://i596.photobucket.com/albums/t...o_2/Image6.jpg Jango I would not leave that stryofoam in there, it could present a fire hazard. |
#4
Posted to sci.electronics.repair
|
|||
|
|||
Hitachi 37LD9000 Inverter tripping, Story in pictures
I would not leave that stryofoam in there, it could present a fire
hazard. Wasn't planning to, just a temp fix till i get appropriate feedback and find a solution, Thanks anyway Mr. Darby |
#5
Posted to sci.electronics.repair
|
|||
|
|||
Hitachi 37LD9000 Inverter tripping, Story in pictures
On Thu, 26 Nov 2009 07:25:07 -0800 (PST), jango2
wrote: I would not leave that stryofoam in there, it could present a fire hazard. Wasn't planning to, just a temp fix till i get appropriate feedback and find a solution, Thanks anyway Mr. Darby I can see three approaches. The first is a brute force approach. It depends on sufficient space between the perforated shield and the back of the TV. Judging by the styrofoam experiment, a rectangular 'can' of that depth could be constructed and the back shield modified so there is additional clearance between the transformers and the (extended) shield. The second is more elegant and more work to achieve. Inverter controller ICs monitor a number of parameters, including output voltage, CCFL current, and even drive current. Determine which parameter is causing the shutdown. Then analyse the circuit to determine if the setting is overly conservative, components have drifted, or a component (driver?) is marginal for this application. The solution might be as simple as changing one resistor, or as complex as redesigning the driver circuitry. The third is simple - check with Hitachi and determine if there is any modification kit to resolve this problem. I don't hold a lot of hope that there is, but ... PlainBill |
#6
Posted to sci.electronics.repair
|
|||
|
|||
Hitachi 37LD9000 Inverter tripping, Story in pictures
Thanks for respnding Bill Brute force hammer n punch? i have clearance between back cover n shield 5 mm displacement? Wht if I cut another hole through? smd filter caps on board too? no schematics for inverter available, no marking on caps How does the black patch and foil work anyways How do i word this innocently to Hitachi to get them to hep? |
#7
Posted to sci.electronics.repair
|
|||
|
|||
Hitachi 37LD9000 Inverter tripping, Story in pictures
On Fri, 27 Nov 2009 07:40:20 -0800 (PST), jango2
wrote: Thanks for respnding Bill Brute force hammer n punch? Well, I was thinking of something like a sheet metal nibbler (drill hole in sheet metal, tip of nibbler goes through, nibble out opening of any desired size ande shape). In this case, 'brute force' meant a solution which avoided the sensitivity to metal without actually repairing the design defect. i have clearance between back cover n shield 5 mm displacement? Wht if I cut another hole through? smd filter caps on board too? There is a hole in the inner shield, I'm guessing it's about 5 cm x 7 cm. I would cut a rectangular hole 6 cm x 8 cm in the perforated shield. Next, build a shallow rectangular pan 6 cm x 8 cm by 5 mm deep with a 5 mm outer rim. Finally, attach the pan over the opening you cut. no schematics for inverter available, no marking on caps How does the black patch and foil work anyways I don't have a clue. How do i word this innocently to Hitachi to get them to hep? Why be innocent? I would start out assertive - "What is the reference number for the service note, change order, or repair kit to solve the inverter shut down problem on a 37LD9000 TV?" PlainBill |
#8
Posted to sci.electronics.repair
|
|||
|
|||
Hitachi 37LD9000 Inverter tripping, Story in pictures
On Wed, 25 Nov 2009 22:10:44 -0800 (PST), jango2
put finger to keyboard and composed: Hitachi 37LD9000 Inverter tripping, green led on, sound ok, no picture. Pics contain textual narration. http://i596.photobucket.com/albums/t...o_2/Image1.jpg http://i596.photobucket.com/albums/t...o_2/Image2.jpg http://i596.photobucket.com/albums/t...o_2/Image3.jpg http://i596.photobucket.com/albums/t...o_2/Image4.jpg http://i596.photobucket.com/albums/t...o_2/Image5.jpg http://i596.photobucket.com/albums/t...o_2/Image6.jpg Jango The datasheet for the Rohm BD9890FV inverter controller states that "a strong electromagnetic field may cause the IC to malfunction": http://www.rohm.com/products/databoo...bd9890fv-e.pdf However, the above warning may be a general one, as it occurs alongside other general warnings including "mounting failures, such as misdirection or miscounts, may harm the device". What if you tried shielding the BD9890FV IC inside a metal box ??? Or what about a grounded metal plate above it, and a plate below it on the underside of the PCB? - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Pictures of Steve Russell's stone crusher onalt.binaries.pictures.woodworking | Woodturning | |||
TIG inverter -- final gate drive assembly PICTURES | Metalworking | |||
Pictures -- My TIG inverter plugged into the actual welder | Metalworking | |||
Pictures -- My TIG inverter plugged into the actual welder | Metalworking | |||
Recovering 2.5 hp motor for phase convertor (long story with pictures) | Metalworking |