fixing back light inverter board - Page 5 - RC Groups
 Apr 27, 2007, 01:26 PM Registered User Helo, I'm french & I'm sorry because I don't speak english very well. If you don't understand my english say me.. I have the same problem with the board inverter V144-001. The problem I don't see the value of the R126,R132,R77,R125.Can you say me the value please. With my control I have this values: R77= 60 K R125= 990 K R132= 0 R126= 0
Apr 28, 2007, 12:20 AM
Registered User
Quote:
 Originally Posted by ced_french I have the same problem with the board inverter V144-001. The problem I don't see the value of the R126,R132,R77,R125.Can you say me the value please. With my control I have this values: R77= 60 K R125= 990 K R132= 0 R126= 0
The resistor marked 0 is 0 ohms.

I cannot read the other values but if you post the numbers that are written on it, that is the resistor value.

For 5% resistors, the first 2 digits = ohms, the 3rd digit is the 10^x value.

For example 472 = 47x10^2 = 4.7K

For 1% resistors, the first 3 digits = ohms, the 4th digit is the 10^x value.

Hope this helps.

Dave
 Apr 29, 2007, 12:40 PM That tree again!!!! Hello, Sorry that you have the same problem with the inverter board. I think you should just need to find the bad transformer and it would fix the problem R77, I see it has number 83K, not sure what that value is. R125 should be 1Mohm (105) R126 has value 242 which is 2400 ohms R132, 0 ohms, a bridge, or fuse... But when I measured it with a meter, both R126 & 132 are 0 ohm as well Looking at the PCB, it seems like 126 & 132 are parallelling together, which doens't make sense. One end of this paralelled 126 & 132 is going to R77, the other end goes to nowhere! maybe the paint mask covers my eyes and my lens... Thanh
 Apr 29, 2007, 02:08 PM Registered User The rest of the circuitry connected to the resistors can affect your ability to measure their value. If you remove them you'll then be able to measure their value.
 Apr 30, 2007, 04:08 PM Registered User Hello. I have change the bad transformer and there is always the problem. But now i suspect the Q1, Q2, Q3, Q4 because the values are diferents. Q1=Q3=R2A=2N3906 Q2=Q4=R1A=2N3904 But when I measured it with a meter there are the diferents values. Thank you very much.
Apr 30, 2007, 11:51 PM
Registered User
Quote:
 Originally Posted by ced_french Hello. I have change the bad transformer and there is always the problem. But now i suspect the Q1, Q2, Q3, Q4 because the values are diferents. Q1=Q3=R2A=2N3906 Q2=Q4=R1A=2N3904 But when I measured it with a meter there are the diferents values. Thank you very much.
Same problem as above - it's hard to get a measurement when they are installed because the rest of the circuitry is also being measured.

If you suspect them, remove them and then test them, or just replaced them since they are very cheap.
Dave
May 01, 2007, 11:55 AM
Registered User
Quote:
 Originally Posted by Probedude Same problem as above - it's hard to get a measurement when they are installed because the rest of the circuitry is also being measured. If you suspect them, remove them and then test them, or just replaced them since they are very cheap. Dave
I work in electronics and i knows all that ("If you remove them you'll then be able to measure their value").

I have change in the first time 1 transformer (measured 1500 ohms) by a new.Now The first and the second (measured 970 ohms) and other (950 ohms). I hope and I think the all transformers are good.

But i hope,someone had a board to measure as me and say me the value.
Q1,Q2,Q3,Q4 ???

I'm very sorry for my english and thank you very much for your aswer.
 May 03, 2007, 01:28 PM Registered User Helo every body. I think: if it's just a starter of neon or neon himself which fautly... There is just one or 2 neon turn off??and other turn on?because they are all turn off. thank you very much.
 May 07, 2007, 01:53 AM That tree again!!!! I think it's possible that if one light tube is bad, the whole thing would turn off for protection. We do need a circuit diagram to know for sure. I don't think anyone has a good working board to test now. Before my board went dead completely, I was trying only one bulb at a time (i.e unplug all bulbs, and plug only one bulb in to see if it's steady on.) Could you try that to see what effect you have? Does it stay on or does it turn off after a few seconds? Here is the values measured from my board: Q1. AB (Red to A, Black to B - according to the graph you posted above): AB : 663 AC : 631 BC : 801 CB : 659 CA : 1023 BA : 1419 Q2 AB: 1560 AC: 702 BC: 688 CB: 1440 CA: 1780 BA: 655 Q3: AB: 713 AC: 643 BC: infinity CB: 720 BA: inf CA: 890 Q4: AB: inf AC: 1254 BC: 691 CB: inf CA: 638 BA: 663 Best regards, Thanh
 May 10, 2007, 12:22 PM Registered User Thank you for your answer. I try only one bulb at a time. The effect is: turn off after a few seconds (the right backlight turn on and turn off after a few second and to left turn off every time). And you, at your home?What is the effect? thank you very much. I think I will by a new board inverter for 200euros.(TOSHIBA in FRANCE).
Jan 04, 2008, 04:23 PM
Registered User

# Darfon v144 install question

Quote:
 Originally Posted by hendercc Success! I RMA'd the Hansol board with www.lcdpart.com and after some delay (they were shut down for a week during the holidays), they shipped me a replacement Darfon v144 board. This is an actual Darfon board. lcpart.com has also updated their web site to reference the actual Darfon board instead of the Hansol board. I installed it yesterday and my TV is back working again. In the mean time, I had purchased a 32" Sony Bravia at Costco since I didn't know if the Syntax Olevia would ever work again. Side by side the Sony blows away the Syntax in picture quality... better color, blacker blacks.
Hello henderec, I also own a non-working LT30HV. Seems like the same problem. Also bought the 32 Sony but went for the XBR. I would hate to throw away the Syntax though. So, my question is "was it a difficult install?"
I am mechanically proficient but have little electronics repair experience. I would probably just buy the part and try to find a local repair shop.

 Jan 04, 2008, 10:04 PM That tree again!!!! look at the yahoo group mentioned in this thread. It has a lot of useful information.I think the concensus is that replace a short transformer would fix the problem. It looks like lcdparts.com also has the replacement board for around \$180. I've not tried it since my monitor is packed and in a storage right now. Thanh
Apr 26, 2008, 09:55 PM
Registered User

# Help with my Olevia LT30HV

I am experiencing the same problem. Did anyone find an inverter board at a more reasonable price? Thanks
 Jul 03, 2008, 04:58 AM Registered User Ok I also have the nasty Dafron V144-001 inverter board in my 30" LCD TV I see a lot of other people are having problems with these. I didnt fix it but I fooled it and It was easy. On the 20 pin oz960 which is a ccfl controller I noticed that pin 10 was rising and staying well above 2.75v thresehold,( more like 3.75v) this will allow the Backlight to start up for a second or two then turn off. The reason for this is pin 9 is low allowing the oz960 to not monitor overcurrent on start up. then as pin 9 rises in voltage pin 10 should be falling in voltage, but mine doesnt. So an easy fix is to put a LED from pin 10 to ground This holds pin 10 to around 2.4v, normal operating voltage. Let me know if it works for you Doing this is at your own risk I believe a common fault with these is the Transformers but I tested mine and they seem ok well close enough he he Cheers and good luck Justin
 Jul 07, 2008, 01:34 AM That tree again!!!! Hi Justin That's a very nice fix. Thanks very much for the info. Thanh