Goodmans GML22W29HDVF / Vestel 17mb29 main board

[kingkebab100]

Guys, You wont beleive this but.....

I brought the TV to work today to take photo and put on Ebay and tried it again....

.... and the darn thing is working perfect WTF   

So I've powered down and will re-try again later..... LOL

Nice 1 for no come backs John

Fingers crossed Romanko  nightmare indeed  :wacko:

[romanko]

Hi. so I`ve sleep well. I am just turned on TV ,was pluged in from last night and is gone mad. when I want change volume down I have now source select there. definitely gone. I will keep them for parts. :mad:

[Contrast John]

Hi Again
Just got another one of these sets in for repair with a similar (but not quite the same) problem. Thought it might be worth comparing with your specimens. Set was stuck in standby and no amount of cable removal would persuade it to start. Found that if I heated the area around IC U696 (MP1583) with a hairdrier the set would operate normally. U696 is located on the top right hand edge of the signals board. Turn off and leave for ten minutes and it was back to the standby problem. Got the impression that this 8 legged step down regulator chip might be faulty. Interestingly it supplies the 3.3 Volt rail for the eeprom which could explain possible eeprom corruption or damage. Never quite sure using a hairdrier though as the heat seems to spread out a bit so guess replacing the IC would be a starting point. Don`t know if I`ll get to try though as the owner is considering his options!
Hope the info might be usefull.
Regards
John.

[romanko]

Hi.hopefully you right. I`ll try and let you know. romanko

[romanko]

Hi again. I`ve been try heat it up and you are right. coming on allthetime. I have two MP`s 1593 DN so ,do you think,can I replace them for thisones ? datasheet says just higher voltage.     romanko

[Contrast John]

Hi romanko
The IC is actually shown as a MP1593 on the schematic, but not sure if the associated components would be the same values for a MP1593. Not easy to tell without markings on the components or the board. Probably worth a try if you`re good at soldering, but keep in mind that you may need to fit the right IC to avoid confusion over whether or not you can use a `93.
Regards
John.

[kingkebab100]

No joy again here fellas... so picture being taken as I type... off to ebay it goes...

Gl with your sets..

[romanko]

Hi again. I`ve been replace the MP1583 from good working board and same problem,so this is not solution. too many problems with cheap tv`s. I`ll lieve one for labouring and give away next two for parts.Have one more Nordmende NM32780 from friend with same problem. If anybody will find out what may be a solution please reply back. good luck-  regards - romanko

[daz]

hi all
dont supose anyone has found a solution to this fault yet?

[Contrast John]

Hi Guys
Was given one of these sets recently with the problem where U696 needs a dose of the hairdryer to start it and spent a little time scoping waveforms. Ended up with the 'assumption' that U696 couldn't deliver enough current at 'power up from standby' to get the set started. Got round the problem by adding a 1000 microfarad low impedance type electrolytic capacitor from the output of L 107 to chassis. ie across the standby 3.3 volt line. Found then that the set started every time. Don't know if this would always work for this problem, or if there is a better solution. Anyone have any further info?
Regards
John.

[daz]

hi john
I went down a similar path, changing c141 470uf for a 1000uf, seemed to have had positive results but only ever seen one and the customer was at the stage where if it acted its self again it was going in the bin, so guess we will never know.
did find someone on ebay who new the secret of this repair and was offering a pcb repair service for about £50 I think, I contacted him and offered him some shiny coins for his secrets but he refused point blank (Meany, hope the Yule tide log slips from his fire and burns his house down)
, but you never know he mite have an Ebenezer moment over xmas and share his secret.
if not lets hope these sets soon pass into history
daz

[Contrast John]

Hi daz
Think we may have discovered his secret! Will keep you posted if any more show up.
Regards
John.

[mrfriss]

Interesting discussion going on here! I have a Prosonic tv with the same mainboard and stuck in standby too.

I'm going to play with some ribbon cables now, could you highlight me which one I need to unplug?

[Contrast John]

Hi
On the first set disconnecting the large white ribbon cable between the main board and dvb board got it started. On the others heating U696 on the mainboard with a hairdrier got the set going. If this is the case try adding the capacitor as suggested. Interested to know the results.
Regards
John.

[mrfriss]

The ribbon cable doesn't do anything (the very thin one).
The power led is on, but the screen stays blank (off).

I pressed some random buttons (tv/av, menu, pg+, pg-, vol+, vol-) and some kind of test program started running... flashing the screen on and off and displaying gradients.
At least this means the panel still works.

...If only I had a hairdrier!