Logik l32digb20

[tom66]

Re: Logik l32digb20

Sorry for not clarifying, the BLON and DIM are the green and brown wires going to inverter board.

BLON: >2V on, <1V off, 1V~2V can't tell.
DIM: 0~3V, with 0V indicating 10% intensity and 3V indicating around 100% intensity.

It's odd that you can't access menu, wonder if the supply voltages are unstable enough to cause the main board to "crash" if you will.

[flocko]

Re: Logik l32digb20

So the 1117 ADJ that was reading Pin 1=0.0 is now Pin 1=1.23
Pin 2=4.97 Pin 2=2.49
Pin 3=5.16 Pin 3=5.15
and the BM 1084 ADJ Tom was right you had back to front 3 2 1 so all look ok

[sordids999]

Re: Logik l32digb20

hi tom the green is 0.05 Volts and the brown is 5.04 Volts but im now only getting one flashing backlight
with reference to the user menu once the backlight is constantly flashing all im getting on the screen is just a LOGIK logo quickly then the screen will just flash

[tom66]

Re: Logik l32digb20

Hmm - if possible see if you can get back to the original flashing...
Because the readings are now pointing towards a bad main or PSU...!

[sordids999]

Re: Logik l32digb20

right at the moment i cant get the backlight to flash constantly it keeps going into standby now after one flash of the backlight,so ill keep trying but if i unplug the cable to the invertor board im getting 3.50 Volts brown 5.15 Volts green

[sordids999]

Re: Logik l32digb20

tom i managed to get the backlight to flash constantly green cable 4.5 volts brown cable 4.8 volts

[tom66]

Re: Logik l32digb20

Looks like it's the main board or power board then. Given the variation, maybe main board. I'm confused about the Vregs and would say try replacing the one Flocko suggests - but not certain as it seems to be OK.
You could try jumpering the backlight signal if you have a pair of 100 to 470 ohm resistors?

[sordids999]

Re: Logik l32digb20

what color marking are the resistors i have loads of spares laying around ?

[tom66]

Re: Logik l32digb20

You can use colour code calculator
http://www.digikey.com/us/en/mkt/cal...resistors.html

[sordids999]

Re: Logik l32digb20

ok whats next if i find some tom ?

[tom66]

Re: Logik l32digb20

You'll need three. My error.

You can jumper the PS ON to 5V standby, turning PSU on (main board disconnected.) 24V should come up and be stable, but backlight should not light.

Then jumper BL ON and DIM to 5V run, turning backlight on.

[sordids999]

Re: Logik l32digb20

Ok tom searched around but cant find any sorry so whats my next option

[tom66]

Re: Logik l32digb20

You would really need to get some - you can try random board swapping...
You can buy them from CPC (free delivery, pack of 50 around £1) or Maplins.

[sordids999]

Re: Logik l32digb20

ok tom i have a maplins by me just ask for 100 to 470 ohm resistors?

[sordids999]

Re: Logik l32digb20

http://www.maplin.co.uk/p/metal-film...resistor-m100k

they ok tom ?

[tom66]

Re: Logik l32digb20

These..
http://www.maplin.co.uk/p/metal-film...resistor-m470r

It's probalby better to get the 100 pack. Keep some spares for future use.
http://cpc.farnell.com/_/mcf-0-25w-4...20This%20Range

Pack of 100 for 49p + VAT, free delivery. Hard to beat that. Will take a few days.

While you're at it, you could order the LDOs in case - they're pretty cheap
http://cpc.farnell.com/texas-instrum...63?Ntt=tlv1117 (33p - 3.3V type)
http://cpc.farnell.com/texas-instrum...117/dp/SC08267 (44p - adj)

Maybe best to consult with Flocko on exact parts he replaced.

[sordids999]

Re: Logik l32digb20

ok tom thanks ill go get some and ill try and get hold of flocko to find out what exactly i need to order ref the LDOs

[flocko]

Re: Logik l32digb20

Hi i can only tell you what i changed and that was the 3.3 regulator and the adjustable one that is above it, so looking at the board left hand side you have one right in the bottom corner then above that the 1117 3.3v this i replaced then above that an 1117 adj i also replaced,take some more reading on the regs with the inverter lead un plugged (BLon+dim) from the Av board and then with it plugged in , as i got a little lost as they seemed to change from the first time you took them, but i think you have a better understanding of them now

[sordids999]

Re: Logik l32digb20

Ok the readings are the same as before and thats with the Blon and the Dim unplugged from the avboard

[flocko]

Re: Logik l32digb20

so all plugged up with the backlights flashing the voltages on the regs stay the same ?well all you can do is swap those regs out and keep you fingers crossed, you have changed the inverter board that did not work,you have a good 24V to the inverter, but the BL on and dim go down when plugged in to the inverter,as the backlight On and dim are generated from the Av it has to be bad regulators.i will also keep my fingers crossed for you.i forgot to say i still have the set i repaired here as it has not been collected but i dont think pulling that apart will help.