TV Recap - Bush (Alba) LCD2280f1080P

[nigeH]

Re: TV Recap - Bush (Alba) LCD2280f1080P

You are still thinking 2.2nF? ---- think 2.2pF

Yes I am ... will do better next time (hopefully!!)

[nigeH]

Re: TV Recap - Bush (Alba) LCD2280f1080P

Evening all

Any ideas where I might locate a schematic?

Seems very similar to the JVC guide layout, but not quite the same....

Not under Bush/Alba/Sharp/Vestel at http://www.toms-service-manuals.com/

[selldoor]

Re: TV Recap - Bush (Alba) LCD2280f1080P

I doubt you will find one- looking for anything specific? Did you try the reflow?
Perhaps some voltage tests and powering up the PS withoit the main board might be next
to see if the lights will say on. Can you post close up pictures of area around the red socket on the PS front and back and the same on the main board at the other end of the connector. Alos can yo do a better picture of the back of the power supply and straight on pictures of the fronst and back of the main board. (daylight is best if you get any )

[nigeH]

Re: TV Recap - Bush (Alba) LCD2280f1080P

Hi... thanks for your help... I've tried a few things and done some reading

- removed and resoldered the HV Caps (and ordered the eBay ones in case!)
- changed the 1000uF for some I had in the drawer to see. Fitted caps tested as (in ohms) HEC 1.8M, 1.4M 1.2M and the SAMXON 5.4M
- reflowed an ugly blob joint on a SMD cap in the HV DC section just in case.
No difference.

With Mainboard connected the point arrowed (in the Top view) changes from the steady 3.84V and rises over two secs to 2V when it trips out.

It runs on standby with the mainboard disconnected (there are only the two boards (plus a tiny one for the RC off the mainboard).

Put a load on the 5V rail (20W Halogen bulb) it glows as you might expect. Same bulb on the 12V rail and it trips out immediately.
Tried before and after the IC804 12V regulator with same result.

Pictures as requested attached - with the standby voltages on the topshot. Can re-crop or re-take if needed - have daylight if not sunshine

Any thoughts on my next move?

[selldoor]

Re: TV Recap - Bush (Alba) LCD2280f1080P

OK just typed a lengthy note and got logged off before I could post it
here is the condensed version
Pic five top right small fuse with an "s" on and Pic2 top right 2 "0" rated
resistors - please test as fuses.
Red socket -test with all connected v at each pin.
Disconnect main and test again.
Ideally it is nice if it can also be tested in the short period when the light is
on - a few pins at a time, but that may not be essential.
Did you get to looking at making up test bulb/s from a 11-14w cfl

[tom66]

Re: TV Recap - Bush (Alba) LCD2280f1080P

Vestel schematics under OEM (since they are one)
http://www.toms-service-manuals.com/...&Search=Submit
Top result.

[selldoor]

Re: TV Recap - Bush (Alba) LCD2280f1080P

Doh! thanks Tom I too looked under Bush and Vestel couldnt believe none came up as I know how much you like them .
Perhaps on Vestel Tips a note "See OEM for schematics" for us memory sieves

[nigeH]

Re: TV Recap - Bush (Alba) LCD2280f1080P

Vestel schematics under OEM (since they are one)
http://www.toms-service-manuals.com/...&Search=Submit
Top result.

Thanks Tom... now you've pointed them out I can't see why I didn't find them...!

OK just typed a lengthy note and got logged off before I could post it
here is the condensed version
Pic five top right small fuse with an "s" on and Pic2 top right 2 "0" rated
resistors - please test as fuses.
Red socket -test with all connected v at each pin.
Disconnect main and test again.
Ideally it is nice if it can also be tested in the short period when the light is
on - a few pins at a time, but that may not be essential.
Did you get to looking at making up test bulb/s from a 11-14w cfl

I hate it when that happens! Thanks for re-typing

Progress (if you call it that) thus far I have tapped out the voltages on the connector. 3.3V amd 12V coming back look a bit odd. See attached. Checked the fuses you pointed out and all the other Fxxx I can find - all ok.

So having watched the excellent video on testing regulators I checked the three on the mainboard.
U12 :output 1.872V from 3.25V supply and 0.608 reference
U122 output 5.15V from 7.97 supply and 3.88 reference
U123 output 7.98V from 13.11 supply and 6.71 reference
Seems in order

Then I realised the PSU and Mainboard are stable as no panel and tubes connected - added the panel and still stable.

Tried the CCFL one set at a time - the set on PL101/102 cause a flash like a lightbulb (same as when both are connected) and the set on PL103/104 caused a longer (half second) flash.

Wired up a test bulb as per another video on this rather fine site and this illuminates for half second duration on both.

I've removed TR100.
The windings look clean - 860 ohms on each secondary - should the primary be 0.1 ohms?

[budm]

Re: TV Recap - Bush (Alba) LCD2280f1080P

https://www.badcaps.net/forum/attach...0&d=1416149675

What are the P/N of those two POWER MOSFET IC102, 104?
Check the resistance between any one of the pins on the right side against the other 4 pins on the left side of the IC and report the readings.
Also check the resistance of the FUSE F101, <1 Ohm?

[nigeH]

Re: TV Recap - Bush (Alba) LCD2280f1080P

https://www.badcaps.net/forum/attach...0&d=1416149675

What are the P/N of those two POWER MOSFET IC102, 104?
Check the resistance between any one of the pins on the right side against the other 4 pins on the left side of the IC and report the readings.
Also check the resistance of the FUSE F101, <1 Ohm?

Hi budm - checked these out:

Fuse F101 reads 0 Ohms

Part number for both is PK8J FDS 8962C

Also noticed none of the other components on that section of the diagram are fitted - D134 and D136 & C139, 140, C115 and C142.

Resistances
IC102
Pin 1 10M
Pin 2 10M
Pin 3 2.1M
Pin 4 2.2M

IC104
Pin1 10M
Pin2 10M
Pin3 2.4M
Pin4 2.2M

These do vary - pin 1/2 falliing and 3/4 rising. Other parts of the circuit I guess.

Checked the voltages - getting 13V on the outputs until the reset. 6V during standby. All without the tubes attached.

[selldoor]

Re: TV Recap - Bush (Alba) LCD2280f1080P

http://www.alldatasheet.com/datashee.../FDS8962C.html


Wired up a test bulb as per another video on this rather fine site and this illuminates for half second duration on both.

Was that with one test bulb AND the normal bulb in place on the other socket?
Just remind me is this 2 bulbs or 4 - if 4 then you need 3 and the test bulb

[nigeH]

Re: TV Recap - Bush (Alba) LCD2280f1080P

http://www.alldatasheet.com/datashee.../FDS8962C.html


Wired up a test bulb as per another video on this rather fine site and this illuminates for half second duration on both.

Was that with one test bulb AND the normal bulb in place on the other socket?
Just remind me is this 2 bulbs or 4 - if 4 then you need 3 and the test bulb

YYYYYYEEEEEEEEEESSSSSSSSSSS!!!!!!!!!!!!
Four bulbs - thanks for that, I had them all unplugged.... plugged in 3 and used the probe bulb and worked along until they stayed on....

Massive thanks to you all for your help and encoragement

Now all I need is a source of tubes and some luck taking the panel apart... Any tips or UK sources for tubes? Panel is 290mm and nine tubes - however tha splits into 4 only time (or a drawing) will tell
edit - it's edge lit 4 x 480mm

[tom66]

Re: TV Recap - Bush (Alba) LCD2280f1080P

I said it would be a bad bulb! But I -had- thought the LG ones were mostly immune...

[nigeH]

Re: TV Recap - Bush (Alba) LCD2280f1080P

I said it would be a bad bulb! But I -had- thought the LG ones were mostly immune...

Yes you did.
Sorry it took so long to catch up!! On the upside I learned a few things along the way....

Tubes are CCFL so perhaps an early (or cheaper) screen?

Once it works again I might try and find out why it whines on standby

[selldoor]

Re: TV Recap - Bush (Alba) LCD2280f1080P

Hurrah!!!!
I dont know about bulbs in the uk perhaps someone else will chime in.
Going out so didnt have time for a good look - this caught my eye and if you could wait
a bargain (if they work and get here in one piece - at that price good for a laugh
http://www.ebay.co.uk/itm/New-2PCS-2...item3ce69b9a44

You will need the right diameter though

[nigeH]

Re: TV Recap - Bush (Alba) LCD2280f1080P

Hurrah!!!!
I dont know about bulbs in the uk perhaps someone else will chime in.
Going out so didnt have time for a good look - this caught my eye and if you could wait
a bargain (if they work and get here in one piece - at that price good for a laugh
http://www.ebay.co.uk/itm/New-2PCS-2...item3ce69b9a44

You will need the right diameter though

Thanks (again) for your help selldoor

Got the verniers out - they are 2.4mm.
Might have to get some of those just in case nothing more local turns up.... and recalling the order of assembly might be fun after a month!