I've read most of the material posted here on convergence problems and have done the following:
1) replaced the convergence amps - replaced both STK392-110 with -180s.
2) inspected and checked resistors (inline) - all look ok
3) checked pico-fuses - all ok
Convergence is still bad and doesn't adjust.
Please let me know if you have ideas on what I can do next...
The TV is a Toshiba 57HDX82 Rear Projection. It is 6 years old. I have the schematics, a multimeter, and I'm borrowing an oscilloscope this weekend.
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History: The TV recently developed the hyper-board disease (video sources were shaky on power-up, then remained shaky, etc.). I had guys from a local shop come out (for $95). They took the big board with them (power and signal) to diagnose the problem. They wanted $300 more to fix it, so I declined and asked them to put it back together. They had a very hard time putting it back together, and the convergence problem began in the middle of this 2 hour struggle. I had the hyper-board repaired (online guy, by mail, $75) and the only problem I have now is convergence. Replaced convergence amps, etc. (see above), and now I'm stuck.
thanks!
Matt
I would suggest to measure the voltages -32V on pins 3, 4 and +32 on pin 5 as well +20V at pin 10 and -20V at pin 17 on both ICs. Compare all the voltages that you're measuring to the schematic.
Double check the solder joints on the ICs as well and measure continuity from the pins to where they're connecting to other components. Also make sure the 1.8 resistor are measuring the correctly values.
Better take it to a tech
U shoud go with a professinol service parson
This sit might help u to find the proper STK392-110 and RCA chaedaper chaedaper !!
i geuss the expert got reason!!
the link1
rate me fixe you!!
The convergence is controlled by a separate power supply board and that board needed to be replaced.
take a look at the following web site information. Unfortunately, some
RCA sets have manual convergence boards - which means you can do
nothing but replace it and adjust the manual controls on the board
itself.
But some of the newer ones (Maybe yours) can be accessed through the
service mode. So, give it a try. I have also copied the part of the
web site that gives the entry code to get into the service mode:
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http://myweb.accessus.net/~090/how2adj.html#5.4
5.4 GE / RCA / PROSCAN
Read the _ SERVICE MODE WARNING _ before proceeding.
To enter service mode, push and hold the [Menu] button on the set.
While holding, push and release the [Power] button, then the [Vol +]
button.
You will now have some information on the screen: "P0 V0"
To actually be able to change these values, you must push [Vol +] on
the remote so the information reads V76. Then pushing on the Channel
+/- will change the "P" value.
P1 - 3 are error codes. If there is a problem with the set that can be
self-diagnosed, the "V" will report the code. These codes are available
in the RCA repair manual.
P4 - 7 control the horizontal size, shift, vertical size and shift.
You may also find a summary leaflet for the service tech clipped
somewhere inside the chassis. The procedures for getting into the
service mode, as well as the service items of interest will be there.
If you're attempting to adjust color or geometry errors, you'll need
the Video Essentials DVD, Laser Disc or some other source of test
material.
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With luck, you MIGHT be able to adjust it back into better alignments.
If you end up needing service, the price of the convergence board - if
you can get it from RCA Parts - should not be over $100, but I have not
actually checked it lately - and it depends on the model.
The installation is quite time consuming, so it may take a couple of hours for a tech to install and align it.
In my opinion the $400 plus charge is way high. I encourage you to look
elsewhere. Also, the RCA web site has a link to authorized service
centers; you might try that, also.
Wishing you the best,
Your TV most likely has one or more possible problems.
Problem #1: Convergence Chip Failure ( common problem )
Here are some of the most common symptoms and example photos of a convergence problem
Solution #1
Solution #2 Solution #1 Solution #2 Solution #1 Solution #2 Solution #1 Solution #2201 views
Usually answered in minutes!
The solution posted refers to an RCA set. My problem statement clearly states that I have a Toshiba TV. Also, the $400 figure I mentioned was for the hyper-board repair (I provided this info for history).
The second solution posted is not useful either. It referred to the wrong make of TV - mine is Toshiba. And it linked me to a site selling convergence amps... Please read my post!
Not a solution.
Please don't respond "take it to a tech". Perhaps the experts that log in during the day have a real solution. Thanks...
Thanks for suggesting things to check. Everything checks out ok, but some of the voltages are off a bit... Please let me know if these voltages are a concern, or if there's anything else I can try.
The 1.8 ohm resistors measure correctly - there are 3 per convergence amp. Solder joints look fine. I measured continuity from all convergence amp pins to another board connection.
Voltages Measured at Convergence Amp Pins (vs. Schematic):
Q751 (Vertical)
[pin3] -31V (-32V)
[pin 4] -32.3V (-32V)
[pin 5] 31.8V (32V)
[pin 8] -21.8V (-20.5V)
[pin 10] 22.8V (20.8V)
[pin 12] -16.6V (-16V)
[pin 17] -21.8V (-20.5V)
Q752 (Horizontal)
[pin3] -31V (-32V)
[pin 4] -32.3V (-32V)
[pin 5] 31.8V (32V)
[pin 8] -16.6V (-16V)
[pin 10] 22.9V (20.8V)
[pin 12] -16.6V (-16V)
[pin 17] -16.6V (-16V)
I have a picture showing the set's convergence problem, if that is
useful. Send an email to mhomiller (at) hotmail (dot) com if you want
me to send the picture.
thanks...
More comments posted here: http://www.fixya.com/support/t940928-tos...
As indicated on the other link, I'll probably consider replacing my new -180s with -110s as a last resort. I'm wondering if my -110s were bad in the first place since the set is unchanged.
Still looking for ideas...
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