Need help with Toshiba 56H80 questions (1 Viewer)

[Jon_Kirkbride]

I have a Toshiba TW56H80 that I have had for two years now. All around, I think this has been a great set and I've been generally pleased with it. Early on, I was having the popping/resetting problem but that hasn't happened for quite some time now. I've always used Video Essentials to keep the levels set right and avoid burn in problems. Generally, I think I've taken good care of the set.

Recently, I purchased a Progressive scan DVD player and an HD STB and wanted to maximize the picture quality. I've never had an ISF calibration done but I have followed instructions for set geometry and do the service convergence. This is when I started to see some problems.

First, when I go into the service mode on the set and run self diagnostics, there is a line that looks like the following:

BLOCK: MAIN SUB

The problem I think I see here is that SUB is in RED. The service manual says that red is NG (which I'm assuming means Not Good). Is this something That I should definitely have a technician look at?

Also, when I first brought up the convergence grid, there was a severe warping of the grid on the left side of the screen. Since they were in the area that is normally in the gray area, and since it didn't affect my daily 4:3 viewing, I never noticed anything. Once I started to fix geometry and converge the set, I found that a number of the settings that "looked right" were dramatically different from the factory defaults. As a test, I recorded all of the service menu values and then proceeded to reset all of the service menu settings to factory default values contained in the service manual. It looked like crap. The biggest problem I saw was when PIP was turned on. The red was extremely harsh in this mode, which appears to be related to the SUB sync issue mentioned above.

Also, I hooked up the Samsung TS160 STB and noticed that when set to output at 720P, I get no picture at all. I know this set doesn't do 720P natively but thought it was supposed to upconvert to 1080I. Should it be able to do this? Is this indicative of some mechanical problem?

I have managed to get the set to a very acceptable level of picture (much better than before I started) but I keep having this nagging feeling that something is wrong and it could be better. If anyone has a good deal of experience with the Toshibas in this series can give me a few pointers, I would greatly appreciate it as I really don't know where to go from here and I would rather not shell out the dollars for a service tech to come out and tell me nothing is wrong with the set.

 

[David Abrams]

Jon,

Your set is not suppose to even accept the 720p signal - that is the newer series of sets. Your set is capable of 1080i, 480p, 480i.

When you adjusted the service level geometry and convergence did you ever do coarse geometry or did you only do point convergence and correct everything with the point convergence? If so you may have put too much strain on the convergence board amps which could lead to failure and distortions.

The factory default settings are generally not accurate as they are a guide and every set comes slightly different from the factory. Did you write down the settings before you changed anything? Were they the same as the factory defaults?

Without looking at the set it is hard to determine if anything is failing or if something just got a little off. Best thing to do is to make sure that you are not maxing any of the picture (geometry) parameters out and go from there.

Regards,

 

[Jon_Kirkbride]

Using instructions I found on a website that deals with Toshibas and using the Service Manual, I performed a mechanical alignment to set the image center and tilt. I then set the picture height and width in the service menu. Then I did grometry in the service menu. and finally, a service convergence.

While most of the factory settings were close to my setup, some were dramatically off. They were even further off after I made my adjustments, but the picture was noticably improved. I did write down all of my original settings.

What still concerns me is the red NG in the SELF TEST screen that I mentioned. Should I have a service tech come out to look at this? It's not under warranty. How much could I expect to pay (roughly)?

 

[David Abrams]

Jon,

I'm not sure. To be safe you may want a service tech out. I cannot tell you what he will charge or what he will find.

Regards,

 

[Mike Hamilton]

Disconnect AC from the set completely and let it set (preferably overnight) to Reset the MCU.
The fact that your settings do not match the Service manual mean nothing, if your image fidelity is still sound. Factory / Service menu settings, general, are nominal settings that are published as a guideline in the event that a major repair such as a board replacement or CRT is performed, and the settings get you back into the general ballpark. Intuition and experience are required to complete the task.

If the Red lettering does not go away from the Reset, it might be best to not power the set up. The diagnostics are pointing to an I2C failure in the "Sub" section. While the set continues to operate, it might be such that it is a time bomb waiting to fail if another condition eclipses a set threshold.

Good luck.