Technika LCD42-910 Stuck in standby

[tom66]

Re: Technika LCD42-910 Stuck in standby

IO board is what I was after. How hard would it be for you to check each pin?

[KevT]

Re: Technika LCD42-910 Stuck in standby

I guess knowing the process would be the main issue. Would you want me to check the voltages across each pair? My electronics knowledge is sketchy to say the least.

[tom66]

Re: Technika LCD42-910 Stuck in standby

Your meter should be set on DC200V.

Measure each pin... try to follow any board numbering if that's not available then just be consistent in whatever pattern you use.

Note & post the reading here.

[KevT]

Re: Technika LCD42-910 Stuck in standby

Taking the schematic I posed before (), do you mean checking the voltages across, say, pins 1 and 2 and repeat for each pair?

Would I remove all other connectors for this, or do they have to remain in place?

[tom66]

Re: Technika LCD42-910 Stuck in standby

Test 1 relative to case.
Test 2 relative to case.
etc.etc.

[KevT]

Re: Technika LCD42-910 Stuck in standby

Well, here goes. I measured from the back of the pin.

With all boards disconnected:
1 - 0
2 - 0
3 - 0.8
4 - 0.8
5 - 0
6 - 0
7 - -0.1
8 - 0
9 - 0
10 - 14.3
11 - 14.3
12 - 14.3
13 - 4.2
14 - 4.2
15 - 4.2
16 - 4.2
17 - 3.3 (5.0 sometimes!)
18 - 3.3 (5.0 sometimes)
19 - 3.3 (5.0 sometimes)
20 - 3.3
21 - 3.3
22 - 3.3
23 - 0
24 - 0
25 - 29.0
26 - 29.0
27 - 0
28 - 0

With all boards connected:
1 - 0
2 - 0
3 - 0.8
4 - 0.8
5 - 2.0
6 - 2.0
7 - 0.5
8 - 0.5
9 - 0
10 - 0
11 - 0
12 - 0
13 - 4.2
14 - 4.2
15 - 4.2
16 - 4.2
17 - 0.5
18 - 0.5
19 - 0.5
20 - 0.5
21 - 0.5
22 - 0.5
23 - 0
24 - 0
25 - 0 (seemed to peak at 29.0 and drop to 0)
26 - 0 (seemed to peak at 29.0 and drop to 0)
27 - 0
28 - 0

I had quite some variations in these measurements, but those are the most consistent I got. Changes to the values happened when I switched the TV on using it's on set button, and after about 30 seconds following a high pitched whining noise. Hmm.

[tom66]

Re: Technika LCD42-910 Stuck in standby

I'm thinking main board issue. Just checking, did you use volts DC?

[KevT]

Re: Technika LCD42-910 Stuck in standby

Yes (solid line, dotted line), and I made sure I was testing right by googling the process, so I'm fairly happy with what I got. Couldn't quite get why pins 25 and 26 dropped dramatically after about 30s though. Not much like the numbers on the schematic.

[tom66]

Re: Technika LCD42-910 Stuck in standby

29V on 24V tells me that your meter battery is probably low or dead... it needs replacement. As a multimeter battery runs flat, readings begin to rise.

[KevT]

Re: Technika LCD42-910 Stuck in standby

Right, I'll do that then. Maybe check the voltages again after.

So it looks more like the main board rather then the power supply?

[tom66]

Re: Technika LCD42-910 Stuck in standby

Since PSU is producing what looks to be OK voltages, yes, it looks to be more main board than PSU right now.

[exmortis]

Re: Technika LCD42-910 Stuck in standby

Since PSU is producing what looks to be OK voltages, yes, it looks to be more main board than PSU right now.

Hi Did you resolve this as i have same issue with a T.v , the tv powers on and the screen lights up then powers down again, and the psu buzz's any ideas.

[KevT]

Re: Technika LCD42-910 Stuck in standby

No, afraid not yet. Getting parts is not easy. I may well have put poor caps on the psu. Did that before I came on here

[exmortis]

Re: Technika LCD42-910 Stuck in standby

No, afraid not yet. Getting parts is not easy. I may well have put poor caps on the psu. Did that before I came on here

i changed some caps on the psu, now the fault has changed the LCD is complete stuck in standby clicks on then off with a couple of secs and the psu still buzzing from the relay unit which clicks over nightmare .

[grime]

Re: Technika LCD42-910 Stuck in standby

hi any idea coz i have the same problem

[grime]

Re: Technika LCD42-910 Stuck in standby

i have multimiter and i have knowledg on electronic part can any one help me to sort out this problem pls

[matyka]

Re: Technika LCD42-910 Stuck in standby

Hi,have the same problem here,any help would be much appreciated.

[matyka]

Re: Technika LCD42-910 Stuck in standby

hi,have the same problem on my board.
replaced the capacitors and I got the same buzzing sound.
have you found out what is the problem ?

[matyka]

Re: Technika LCD42-910 Stuck in standby

hello,after I took the logic board off and try to power on ,but after a few seconds shut off on goes in standby mode again .
I managed to take some measurement on PL816 and all are good just one the number 13 should be +33v and I have no reading .
Someone would tell me the next step would be please ???