BELINEA 10 20 05 no picture, confused

[EGuevarae]

Re: BELINEA 10 20 05 no picture, confused

Those caps on inverter board are:

4 pieces of NICON, 56 uF, 25 V, 105°, F204C EVL, green

Few posts before I have written this about voltages on PSU output (to inverter board):

Connector:

Bright. (37 mV*) | GND (0 V) | VO (12 V) | VO (12 V)
-------------------------------------------------
ON/OFF (4,15 V) | GND (0 V) | GND (0 V) | VO (12 V)

Bright. 37mV with disconnected LCD panel. ON/OFF (4,15 V) with monitor turned on (green LED shining).

About PSU board caps:

2 pieces of Ltec 1000 uF, 16 V, 105 °C, 4806D
1 piece of Ltec 680 uF, 16 V, green
2 pieces of Ltec 470 uF, 16 V, 105 °C, 4903D
1 piece of Taicon 47 uF 50 V, it is near main cap filter.

but with stable output voltages, I don't think that the PSU caps are bad.

One note - the monitor is manufactured in 2005.

I've seen that NICON caps on Sampo inverters (two, not four). Although visually OK they were bad (three times so far). But you can go for the V reaching the MOSFET. That would be my next step.
And as for the V readings already posted, I might need new glasses, as even now I had trouble finding them : three passes around the posts to see them. Sorry.

[dvorav]

Re: BELINEA 10 20 05 no picture, confused

I've seen that NICON caps on Sampo inverters (two, not four). Although visually OK they were bad (three times so far). But you can go for the V reaching the MOSFET. That would be my next step.
And as for the V readings already posted, I might need new glasses, as even now I had trouble finding them : three passes around the posts to see them. Sorry.

Never mind. It can happen to anyone.

Talking about bad caps, I have always thought, that caps are degrading in continuous way. This case is most likely sudden death....

Anyway, I'll probably give up this case... it is too much complicated... too much time and effort and still nothing.

Thanks for all posts.

[dondrusco]

Re: BELINEA 10 20 05 no picture, confused

Hi!

I will continue in this thread with model Belinea 2080 S1, because it looks similar to 10 20 05

It has very strange behaviour.

I do burn-in test (amber power led, enhanced menu).
After two minutes it stops working.
It shuts down backlight and starts blinkig power led.

But when I want to measure voltage at regulators, it starts working again for a while.

There is only one difference to Acer AL2021. It has at one regulator 2,5V, but this one has 1,8V only. Others are the same.

It is temperature - sensitive, too. When board uncovered, it works longer, than covered.

Might volage be the problem? I don't know exact specifications of panels, Acer has LG-Philips panel and Belinea has AUO M201UN02 v.5.

P.S. Power board was recapped.

[PlainBill]

Re: BELINEA 10 20 05 no picture, confused

Hi!

I will continue in this thread with model Belinea 2080 S1, because it looks similar to 10 20 05

It has very strange behaviour.

I do burn-in test (amber power led, enhanced menu).
After two minutes it stops working.
It shuts down backlight and starts blinkig power led.

But when I want to measure voltage at regulators, it starts working again for a while.

There is only one difference to Acer AL2021. It has at one regulator 2,5V, but this one has 1,8V only. Others are the same.

It is temperature - sensitive, too. When board uncovered, it works longer, than covered.

Might volage be the problem? I don't know exact specifications of panels, Acer has LG-Philips panel and Belinea has AUO M201UN02 v.5.

P.S. Power board was recapped.

Possible bad caps, or a heat sensitive component. Try applying heat / cold to specific areas of the board to localize the fault.

PlainBill

[dondrusco]

Re: BELINEA 10 20 05 no picture, confused

OK - I found, that one of voltage regulators is too hot.
It is this LT1084 with 1,8V voltage. When I cool it, it works.

But I'm not able to buy new one in that package.
Is it possible to use LT1117? LT1084 is 5A, LT1117 is 1A only.

In Acer AL2021, and in Belinea 10 20 05 there are LT1117.
But both give 2,5V, instead of 1,8V

[PlainBill]

Re: BELINEA 10 20 05 no picture, confused

OK - I found, that one of voltage regulators is too hot.
It is this LT1084 with 1,8V voltage. When I cool it, it works.

But I'm not able to buy new one in that package.
Is it possible to use LT1117? LT1084 is 5A, LT1117 is 1A only.

In Acer AL2021, and in Belinea 10 20 05 there are LT1117.
But both give 2,5V, instead of 1,8V

You are ignoring some characters from the part number. LT1084 is a three terminal regulator available in both fixed and adjustable versions. The version is covered in the characters following LT1084.

I would say the LT1117 is PROBABLY not an acceptable substitute. At 5A, the LT1084 should be overkill for this application, but it failed. At least one datasheet shows the LT1117 as rated for 800ma.

PlainBill

[EGuevarae]

Re: BELINEA 10 20 05 no picture, confused

You are ignoring some characters from the part number. LT1084 is a three terminal regulator available in both fixed and adjustable versions. The version is covered in the characters following LT1084.

I would say the LT1117 is PROBABLY not an acceptable substitute. At 5A, the LT1084 should be overkill for this application, but it failed. At least one datasheet shows the LT1117 as rated for 800ma.

PlainBill

The AL2120 has the variable type. Unless you are sure that the amp rating is 1a or less, don't go that way. You will only be changing the part again, or make your problem bigger (or both ...)

[dondrusco]

Re: BELINEA 10 20 05 no picture, confused

I replaced 1084 on the right side with 1084 on the left. Left one I replaced with 1117. No change.

I replaced capacitors (330uF and 22uF) on the right of 1084. Monitor won't start, only green power led blinks. When I disconnect the panel cable, everything is OK, but no display .
I measured voltage on the panel - disconnected 5V, connected only pending 0,5-2,5V as power led blinks.

I replaced SMD P-MOS SI9435. Input is 5V, but output of this FET oscillating. I don't know, why. Weak 12V to 5V supply?