1. Home
  2. Electronics Repair
  3. Samsung PTV STK392-040 replacement caution notice

Samsung PTV STK392-040 replacement caution notice

I went on a call last week on a Samsung Proj. model PCN5425R which had a dynamic convergence problem. I just received the two new STK's which I ordered, and they came with the following notice:

IMPORTANT SAMSUNG STK392-040 REPLACEMENT INSTRUCTIONS Instant failure of the new device will happen when replacing this device on ALL Samsung projection televisions unless the following precaution is taken. Before installing your new STK's we recommend clearing any erroneous data from the convergence memory that may damage the new parts before installing the new parts. Using the OEM remote, for the TV, power on the TV and press

1-8-3. This will reset the factory convergence data. You should see a cross hatch on the screen verifying that you are in convergence mode. Then press the button to save the reset data, then press button to exit.

During that first service call I removed the convergence board, brought it to the shop and removed the two IC's in preparation for installing the new ones when they came in. The preceding notice suggests that perhaps I should have performed this "reset" procedure with the suspected bad IC's before I removed the board from the set. Does that sound right? If so would I have to reinstall the old chips, take the board back to the customer's home and perform the reset procedure and then replace the parts? I can do that if necessary however, now I don't know which chip went in the left or right position. Would that matter? So I'm somewhat confused. Can anyone shed some light on this? Thanks for any help. Lenny.

Reply to
captainvideo462002
Loading thread data ...

I never heard of that, with any brand TV. Where did you get the IC's from? Dani.

Reply to
Dani

Maybe in some cases scrambled PROM data caused / could cause some wild scan/convergence scenario that would overstress the new devices?

I doubt that the devices require a specific location unles some special markings exist.

I went against Panasonic factory advice and installed OEM devices in my PT51DX80A. That was two years and many hundreds of hours ago.

If you want to be 100% safe install the old devices and go back to the customer and do the reset provided the old devices worked well enough for you to view the setup and were not endangering other components.

Reply to
Meat Plow

e quoted text -

The replacements came from Prelco. Lenny

Reply to
captainvideo462002

quoted text -

Aw looky, I got a new fanboi.

...heh

Reply to
Meat Plow

quoted text -

Disregard the wise crack, sorry :)

Doesn't really matter where they came from. You asked what to do about the reset I advised to be 100% safe, do it with the old devices if safely possible. My addition of the PT51DX80A was just an example to confuse you further.

Reply to
Meat Plow

You can run the set with the power to the output ICs removed or with them out completely. It will not change the reset proceedure which just wipes the data in the EEPROM for the convergence generator.

I have fixed dozens of these sets and you are unlikely to blow the new chips instantly unless there is a large d.c. offset on the inputs. If that is the case the DCU is likely bad and a reset will not solve it. The real reason to reset these is that sometimes they have corrupt data that causes the chips to run hot due to exagerated correction waveforms. They won't blow immediately but you will find it hard to align and the chips will run even hotter than normal. The run hotter than most sets that use them anyway.

I have a good discussion of convergence repairs in general in the first 10 posts here:

formatting link

Leonard

Reply to
Leonard Caillouet

I would find it hard to verify that the reset worked without any visual indication.

As I mentioned in my original reply to the poster.

Reply to
Meat Plow

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.