Question about Sony KP-57HW40 57" Rear Projection Television

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Missing negative 21v going to convergence amps, the positive 21v is running high at 31v no fuse links open, no burned resistors. seems like amps are ok but the circuit for the convergence b+and b- is strange... not scan derived or right off smps. no shorted transistors. any ideas?

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Yes

Posted on Feb 23, 2011

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0helpful
1answer

How can I fix the red shadowing that's on the screen

That's probably your convergence misadjusted. You can go into the TV menu & adjust the convergence. If you are not able to converge properly, then you most likely will need to replace both convergence ICs & the resistors that have burnt open. Unless you have the wherewithal to perform the parts replacement, I highly recommend a professional do the work.
It is also possible that the pins of the convergence ICs have unsoldered themselves, due to heat. If you catch this before they cook themselves & open the resistors, you can avoid the process of replacing ICs & resistors, but usually it's too late.
2helpful
2answers

Convergence Resistors keep burning up

Some simple advice---if resistors are smoking one of the chips is shorted----The set has two voltages that go to them--one a positive voltage and one a negative voltage.

If either chip is shorted you can replace the resistors all year and not get anything. The resistors are protection in case one or both chips short----

Remove all old heat grease and install two new chips and replace the resistors at the same time.

Note that the set may have pico fuses on the power board also.
0helpful
1answer

How do you aline the picture

There is a menu setting called convergence.This allows the customer to align the red,green and blue colors.If the colors do not respond to the adjustments you are trying to make,then you need to replace the convergence IC's and check all associated resistors in that circuit.The resistors could be either burned visibly or open when checked with an ohm meter.If you replace the IC's and have missed a bad resistor,you could burn up the new convergence amp IC's.
0helpful
1answer

I have a convergence problem.

did you check the power to the IC's ... normally when either one of the IC's burn out it takes out the power supply ..... make sure there is both a positive and a negative supply present there ... possibly + and - 28 volts or so .... if any of the voltages are missing ,check the 5 amp fuses that look like little green resistors on the power supply board ... that should solve your problem ....
0helpful
1answer

Convergence problem philips rear projection tv.

All convergence circuits require two voltages which are equal, one being positive the other negative. Check the power supply for these two voltages and then see if you're getting them at the output ICs. I suspect one of them is missing or low. If there are no cooked resistors near the ICs, inspect the fuses that protect those two voltage sources or the regulating devices themselves.


michtech
0helpful
3answers

Convergence

Did you check the resitors out of circuit? As its very rare when a Hitachi doesnt open at least two on the affected circuit. If you checked the resistors in circuit an open resitor will read good even though its actually open.
0helpful
1answer

HITACHI 65SWX20B turns off in 3 seconds

On most Hitachi circuit boards there are small green lights in the circuitry that show if a section of the set is working. Also,there are small protection fuses that look like resistors on the board around the power supply transformer. Check to see if any of those are open and it will lead you to the trouble spot. More than likely on that set it is convergence, vertical, Cold solder in horizontal (FBT or H.Drive xfmr.), cold solder at vert. output, regulator i.c., or audio out. Make sure you check the fuses that go to the convergence amps and look for discoloration on resistors surrounding conv. STKs. These are prone to change in value or burn up. Hope you have some luck solving this, Russmann.
1helpful
1answer

Have a double picture. manual says its convergentsbut cant seem to adjust the red side to side.

If the convergence will not adjust then 1 or more of the convergence amp ic's have failed. Most times just replacing the ic's will correct the problem, but sometimes when and ic fails there is other damage such as open or burned resistors or open cp (circuit protect fuse). If you want to reply with a make and model I can provide part #'s and locations.
0helpful
3answers

Distorted sound

This is an automatic high end amp. Make sure you are using 8 ohm speakers. If the connections are correct, also use good quality speaker wire.

If this makes no difference, it seems that it would need to go to the repair shop.
0helpful
2answers

Blue glow

The convergence amps have most likely failed and taken with them the +/- 30v line. Your unit takes two STK392-040 Sanyo built Ics at board location Icz103 and Icz104 and usually one or more pico fuses and some low ohm resistors. F1018 sometimes opens due to stress but generally it's just the two 6.3 amp pico fuses and if they have opened I strongly recommend replacing them with a 6.3 amp slo-blo pico.
The low ohm resistors at RZ147, RZ146 usually show signs of heat stress and may even be burned beyond recognition. Testing at that point is almost unnecessary but will confirm their change in value. Almost always they need to be replaced.
A quality shop will have this unit back on its feet in no time - faster if they have the parts in-stock, which you might ask about when you shop around for a good repair facility.
Have a great day!
Bill
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