Technika 22-880 startup issues

[notallbad]

Re: Technika 22-880 startup issues

Only getting 2.38v on ICE3BR0665J VCC pin in stby and 3.2v when on, Tech Sheet says between 10.5 and 25v.

[tom66]

Re: Technika 22-880 startup issues

Where is your ground going?

[notallbad]

Re: Technika 22-880 startup issues

Sorry, don't understand.

Via D701 and C704 TO Chassis???

[tom66]

Re: Technika 22-880 startup issues

The negative lead of the multimeter sorry

[notallbad]

Re: Technika 22-880 startup issues

Oh, chassis screw.
Now with neg probe to C706 neg leg.
18v whilst led flashing, then 13.64v while in stby and 18.41v when on. So spotted my mistake there.

[tom66]

Re: Technika 22-880 startup issues

OK you are now measuring the primary-side "ICE" relative to primary side ground?

Blinking power LED is rarely power supply on these modern vestels. Usually it is a main board issue.

What is main board model? 17MBxx-x?

[notallbad]

Re: Technika 22-880 startup issues

17MB60-3.1, I was afraid of that.

Not sure if you have read an earlier post but in the Diagnostic page of the Service Menu it shows NOK, is this Not OK as opposed to the others that just read OK? Do you happen to know?

[tom66]

Re: Technika 22-880 startup issues

SM


Of interest is page 66.

Problem: LED blinking, no other operation
This problem indicates a short on Vcc voltages. Protect pin should be logic high while normal operation. When there is a short circuit protect pin will be logic low. If you detect logic low on protect pin, unplug the TV set and control voltage points with a multimeter to find the shorted voltage to ground.

Locate Q178 for PROTECT indicator. Test point TP202.

[notallbad]

Re: Technika 22-880 startup issues

Thats gonna be on the solder side, bummer. Oh well, here we go.

Aha just spotted it on component side, this is getting too easy.

Thanks Tom.

[notallbad]

Re: Technika 22-880 startup issues

TP202 reads 3.3v whilst flashing led then 0v whilst in stby, then 3.3v again whilst led flashing when powering on out of stby and remains whilst on and working.

[tom66]

Re: Technika 22-880 startup issues

OK, that may be OK then. But check all the voltages that feed in to it: 24V_VCC, 18V_VCC, 12V_VCC etc. The appropriate points are found at the diodes.

[notallbad]

Re: Technika 22-880 startup issues

Looking for the diodes you suggested.

[notallbad]

Re: Technika 22-880 startup issues

Whilst on

D184 3.29V, 5V, 3V
D185 3.29V, 4.3V, 2.98V
D186 3.29V, 3.3V, 5V

[notallbad]

Re: Technika 22-880 startup issues

Now it appears stuck in stby, no response to remote or keypad.
Powered down and restarted but still no joy.
Shall try powering down for a while and retry.

[notallbad]

Re: Technika 22-880 startup issues

U180 Adj Reg is reading Pin 3 - 8v, Pins2 and 4(tab) - 5v and Pin 1 - 4v
Across Pins 1 and 2 reads 1.2v.

Is that Pin1 - 4v looking suspect?

Edited - Erm, no I guess not, sorry.

[notallbad]

Re: Technika 22-880 startup issues

I think this main board is screwed, the main chip U157 is running hot within seconds of being on.

The front led sometimes comes on and flickers, not the usual led flashing, and other times comes on solid. No backlight on but have good 24v and 3.1v on dim.

[notallbad]

Re: Technika 22-880 startup issues

So just for future reference/interest
These are readings whilst powered from mains but no response from remote or keypad
1 3.1v---------11 5v
2 3.1v---------12 5v
3 3.1v---------13 5v
4 11v-------14 11v
5 5v-----------15 5v
6 5v--------16 11v
7 3.1v ----------17 0v
8 0v--------18 0v
9 0v-----------19 0v
10 0v-------------20 0v

[notallbad]

Re: Technika 22-880 startup issues

I suppose it is possible the SW is corrupt but doubt it.
Also presumably as the tv does not start up properly it is not possible to update the SW via USB.

[tom66]

Re: Technika 22-880 startup issues

There is a method in the linked SM on how to update firmware without ever seeing the LCD light up (just need remote & USB key), but I'm not sure if it will work if in protect mode.

[notallbad]

Re: Technika 22-880 startup issues

What the hell, shall have a go and see, its not like its gonna break it anymore than it already is, well I guess it could.