Forum > LCD TV forum
Goodmans GML22W29HDVF / Vestel 17mb29 main board
mrfriss:
Just to be sure, I quickly made the attached image to check for the possible repair options for adding/replacing a capacitor.
Could someone quickly check if I am looking at the right components and connections?
Option #1 replaces the current 470uF capacitor for a 1000uF, I think I'm looking at the correct part (C141)
Option #2 adds a 1000uF capacitor, but I'm not sure I'm connecting this in the right way... Is that cube part L107 and is the output on the right?
Thank you!
Contrast John:
Hi Again
Option #2 is the one I used. Exactly as in your picture. Soldered the positive of the capacitor to the right hand tag of L107 (output) and attached the negative leg of the capacitor to the earth screw.
Good Luck
John.
mrfriss:
An update again from my side; I tried adding and changing capacitors, but no luck...
I found this thread: http://www.tv.quuq.org/forum/index.php?topic=3433.0
It is somewhat the same topic as in here, but the problem has been found in the psu.
I will try adding a 1k resistor between pin 1 of IC301 and ground tomorrow.
While fiddling with capacitors I did some measurements and found that when the set is plugged in and the power button is on, the standby pin puts out around 1,6V. The documentation says standby is ON between 2 and 5 volts and off when 0. Would it be an option to ground this pin so it stays 0?
Another thing is that my unit seems to be stuck in some kind of test mode; when I plug it in, wait for it to power on (blue led comes on) and press the program+ or program- button, it shuts off the blue led, but after 10 seconds or so it starts up the display, flashing the screen slowly and showing black to white gradients...
Finally I found the ebay seller who offers replacement sets, I emailed him, but he want to have my defect board. Clearly he knows how to overcome the problem, but won't share it.
While looking at his pictures though, I noticed a different capacitor on his boards; he seems to have changed c536, maybe someone else knows if this could be an option that makes sense.
Thanks!
Contrast John:
Hi mrfriss
The 1k resistor mod is a possible cure for a lazy ccfl backlight tube. If this was your problem you would have the symptom of sound ok but no backlight illumination. Switching the set in and out of standby would not be an issue.
Seem to recall that the documentation about the standby switching voltage was incorrect in some way but can't remember the exact details.
Think your set is exhibiting a fault different to mine because it appears that you are able to bring it out of standby. From the description it sounds like a corrupted eeprom IC stuck in some sort of test mode. Try holding the menu button on the remote control for a few seconds while the screen is flashing. Sometimes it can act as a reset.
Checked on the circuit for c536. Assuming the numbers are the same on this version c536 also decouples the standby 3.3 volt line - just a bit further downstream. So upgrading it would have the same effect as either of the capacitor mods you have tried.
Regards
John.
mrfriss:
Unfortunately no luck with the menu button on the remote or set itself...
But you are right, I CAN get out of standby mode, either with the buttons on the set itself or remote control. Only thing is that it goes into some kind of testing mode.
I'm going to look into the eeprom, maybe there is an alternative way to get it out of reset or something.
If anyone has any thoughts, please let me know!
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version