Hanns-G HG281D, LCD Monitor no power

[retiredcaps]

Re: Hanns-G HG281D, LCD Monitor no power

It is possible that the 7 electrolytic caps clustered around V33S and V18S are dried up and causing the fluctuating voltage. As I have mentioned several times this particular monitor runs temperature hot and warrants a complete recap of both the power board and main board.

[mmamuk]

Re: Hanns-G HG281D, LCD Monitor no power

...it looks like the power board has all Panasonic caps (T vent). So for now, let's assume the power board is working properly.

Out of curiosity, how can you tell they are a Panasonic caps (T vent) from any other make?

[retiredcaps]

Re: Hanns-G HG281D, LCD Monitor no power

Out of curiosity, how can you tell they are a Panasonic caps (T vent) from any other make?

2+ years and almost 6,100 posts, I better know!! There is no guide. Just staring at a lot of pictures and learning from past and present contributors like PCBONEZ, PlainBill, jetadm123, alexanna (in this subforum), etc.

Panasonic makes "T" vents.
United Chemi-con makes "Y" vents.
Rubycon makes "K" vents.
Nichicon makes "X" vents.

The above 4 are all Japanese companies and are held in the higest regard with respect to quality, reliability and longevity capacitors.

Most of the other cap brands are "X" vent.

[retiredcaps]

Re: Hanns-G HG281D, LCD Monitor no power

Though I did miss one obvious counterfeit picture in this thread just recently.

https://www.badcaps.net/forum/showthread.php?t=21050

[mmamuk]

Re: Hanns-G HG281D, LCD Monitor no power

Yes. The "fat tab" and pin 2 are electrically connected.

So they are electrically connected internally somehow, but externally physically it looks as if pin 2 is NOT connected to the PCB?

[retiredcaps]

Re: Hanns-G HG281D, LCD Monitor no power

So they are electrically connected internally somehow, but externally physically it looks as if pin 2 is NOT connected to the PCB?

Correct. You can still measure the "cut" pin and it will read the same as the fat tab.

[mmamuk]

Re: Hanns-G HG281D, LCD Monitor no power

As others mentioned, we need some higher quality photos, but from what I can see it looks like the power board has all Panasonic caps (T vent). So for now, let's assume the power board is working properly.

Take your boards to a window ledge on a sunny day. Put your camera on macro mode for clearest and sharpest pictures.

Here's my latest attempt at the photos, which were taken this evening (when the natural light was at its low) using MACRO mode. If they still require further improvement I could do this tomorrow morning in early morning sunlight (assuming it's sunny) in MACRO mode.

The first batch are for the Power Board.

JPG4 == Top Left of PCB
JPG5 == Bottom Left of PCB
JPG6 == Bottom Right of PCB
JPG7 == Top Right of PCB

I see now what you mean by T vent - the Caps have the letter "T" embossed on them.

[mmamuk]

Re: Hanns-G HG281D, LCD Monitor no power

The next batch are for the Logic/Signal Board.

JPG2 == Top Left of PCB
JPG3 == Bottom Left of PCB
JPG4 == Bottom Right of PCB
JPG5 == Top Right of PCB

[retiredcaps]

Re: Hanns-G HG281D, LCD Monitor no power

It is possible that the 7 electrolytic caps clustered around V33S and V18S are dried up and causing the fluctuating voltage.

From your picture, I think I see CapXon branded caps. They are one of the worst, if not the worst, makers of caps.

If you have never soldered before, I suggest either practising if you have the equipment or getting a co-worker (properly motivated with a free case of beer) to change out the caps on the main board.

Replacing caps on the main board is more difficult than the power board as it is typically multilayer versus a single layer for the latter. Multilayer means more copper planes to soak up the heat from your iron tip making it more difficult to desolder caps.

[mmamuk]

Re: Hanns-G HG281D, LCD Monitor no power

From your picture, I think I see CapXon branded caps. They are one of the worst, if not the worst, makers of caps.

If you have never soldered before, I suggest either practising if you have the equipment or getting a co-worker (properly motivated with a free case of beer) to change out the caps on the main board.

Replacing caps on the main board is more difficult than the power board as it is typically multilayer versus a single layer for the latter. Multilayer means more copper planes to soak up the heat from your iron tip making it more difficult to desolder caps.

Presumably you're referring to the 7 electrolytic caps clustered around V33S and V18S on the Logic Board? You'd like me to me to change these for the time being and NOT the others. There are 13 in total on the Logic Board.

Impressed by your recognition that they were CapXon from the aerial view of the shots. I suppose that's experience for you.

The specifications on Caps say they are:

10uF, 16V (~4mm dia) 5 off
100uF, 16V (~6.5mm dia) 2off

Anything else I need to specify when ordering? If so, where do I get those specifications from?

What make and specifications would you recommend I replace the 7 with?

Thanks.

[retiredcaps]

Re: Hanns-G HG281D, LCD Monitor no power

Presumably you're referring to the 7 electrolytic caps clustered around V33S and V18S on the Logic Board? You'd like me to me to change these for the time being and NOT the others. There are 13 in total on the Logic Board.

Ideally, I recommend all 13 be replaced. Changing 7 and leaving 6 doesn't make much sense with respect to:

a) CapXon makes terrible caps
b) The cost of 6 extra caps is probably $3.00 USD

Impressed by your recognition that they were CapXon from the aerial view of the shots. I suppose that's experience for you.

CapXon uses a "X" vent and I could see a "pX". They are also black and white sleeve color.

The specifications on Caps say they are:

10uF, 16V (~4mm dia) 5 off
100uF, 16V (~6.5mm dia) 2off

Anything else I need to specify when ordering? If so, where do I get those specifications from?

What make and specifications would you recommend I replace the 7 with?

Before I can recommend suitable replacements, I need to know the series of the caps. This is usually a 2 letter code. For example, on your power board the Panasonic caps are likely FM or FC series. CapXon makes multiple series and we need to find the right replacement series.

[mmamuk]

Re: Hanns-G HG281D, LCD Monitor no power

Ideally, I recommend all 13 be replaced. Changing 7 and leaving 6 doesn't make much sense with respect to:

a) CapXon makes terrible caps
b) The cost of 6 extra caps is probably $3.00 USD



CapXon uses a "X" vent and I could see a "pX". They are also black and white sleeve color.



Before I can recommend suitable replacements, I need to know the series of the caps. This is usually a 2 letter code. For example, on your power board the Panasonic caps are likely FM or FC series. CapXon makes multiple series and we need to find the right replacement series.

There are actually 20 caps (7 + 13) and they are:

10uF, 16V, ~4mm dia. ST series (12 off)
100uF, 16V, ~6.5mm dia. ST series (3 off)
100uF, 16V, ~4mm dia, ~10mm tall, KM series (2 off)
470uF, 16V, ~6.5mm dia., ~12mm tall KM series (3 off)

Thanks, once again, for your time and effort.

[retiredcaps]

Re: Hanns-G HG281D, LCD Monitor no power

1) Both CapXon KM and ST are general purpose caps. You can tell by looking at the datasheet by the ABSENCE of the words "low ESR" or "low impedance" and the missing ESR values in the table.

2) In addition to making sure the caps fit and having the correct voltage and capacitance, you need to match or exceed the ripple characteristics of the original caps.

3) I'll let my European fellow members advise on where to buy, but if you want to stick to Panasonic I suggest

10uF 16V Capxon ST ripple = 18 ma, Panasonic GA = 30ma (digikey part number P14482-ND - 22 cents each)

100uF 16V Capxon ST = 68 ma, Panasonic FC = 290ma (P11198-ND - I chose this one because it is 105C - alternative is Panasonic KA at 85C)

100uF 16V Capxon KM = 125ma, Panasonic M = 180ma (P5138-ND - arrgh 85C cap - alternative is FR 105C with 280ma)

470uF 16V Capxon KM = 370ma, Panasonic M = 440ma (P5141-ND smallest diameter is 8mm and 85C cap - alternative is FR 105C with 950ma)

4) I'll leave it to you to doublecheck all the suggestion in terms of height, diameter, voltage, capacitance, ripple, etc.

5) PCBONEZ talks about all the above terms here

https://www.badcaps.net/forum/showpo...30&postcount=7

6) Here is another example of matching cap values (regulars may skip)

https://www.badcaps.net/forum/showpo...4&postcount=19

[Recycler]

Re: Hanns-G HG281D, LCD Monitor no power

Sweet, those Capxon caps may be the source of your problem. I agree with retiredcaps that replacing them is the first thing to try.
Hope you'll report back mmamuk.

Cheers.

[mmamuk]

Re: Hanns-G HG281D, LCD Monitor no power

Sweet, those Capxon caps may be the source of your problem. I agree with retiredcaps that replacing them is the first thing to try.
Hope you'll report back mmamuk.

Cheers.

I will report back but it may be a while because:

(i) I'll need to source the components from a UK supplier (never sourced electronic components before, so this will be a new experience)
(ii) Will need to acquire a good soldering iron (again never done that before)
(iii) Will need to learn the art of de-soldering from a PCB and re-soldering onto a PCB (never done that before)

All in all a challenge for me, but one I'm keen to attempt.

[mmamuk]

Re: Hanns-G HG281D, LCD Monitor no power

3) I'll let my European fellow members advise on where to buy, but if you want to stick to Panasonic I suggest

10uF 16V Capxon ST ripple = 18 ma, Panasonic GA = 30ma (digikey part number P14482-ND - 22 cents each)

100uF 16V Capxon ST = 68 ma, Panasonic FC = 290ma (P11198-ND - I chose this one because it is 105C - alternative is Panasonic KA at 85C)

100uF 16V Capxon KM = 125ma, Panasonic M = 180ma (P5138-ND - arrgh 85C cap - alternative is FR 105C with 280ma)

470uF 16V Capxon KM = 370ma, Panasonic M = 440ma (P5141-ND smallest diameter is 8mm and 85C cap - alternative is FR 105C with 950ma)

I'll stick with the Panasonic Caps, given they are highly reputable on this Forum.

Can anyone advise me the best place to source these components, which is cost effective price wise and delivery wise?

Thank you.

[retiredcaps]

Re: Hanns-G HG281D, LCD Monitor no power

All in all a challenge for me, but one I'm keen to attempt.

You may find this thread helpful in terms of tools, techniques

https://www.badcaps.net/forum/showthread.php?p=211983

Also, this forum has an excellent written recap tutorial

https://www.badcaps.net/forum/showthread.php?t=485

[jetadm123]

Re: Hanns-G HG281D, LCD Monitor no power

I usually don't recommend cap repair kits off of ebay, but seeing how parts suppliers charge outlandish fees to ship to the UK and the rest of europe/asia, I'll make an exception. I believe shipping should be cheaper and you can check shipping charges before you buy. You can go to ebay and enter HG281D in the search box and you'll see several kits for your mainboard. The caps are not panasonic, but I believe the seller does use name brand caps. Match up the cap values and quantities in the listing with the caps on YOUR board. If the values differ, then email the seller and ask for substitution(s). Hint: based on the number of kits sold, it points to the mainboard caps as a major problem.

Of course, any UK member is welcome to chime in with a cheaper alternative.

[retiredcaps]

Re: Hanns-G HG281D, LCD Monitor no power

I usually don't recommend cap repair kits off of ebay,

Sometimes I can't help the feeling that this forum is being picked over/stalked by ebay sellers selling kits with big margins.

We have already had people say that they have been referred by ebay sellers to this forum when the cap kit doesn't fix their problem.

[mmamuk]

Re: Hanns-G HG281D, LCD Monitor no power

You may find this thread helpful in terms of tools, techniques

https://www.badcaps.net/forum/showthread.php?p=211983

Also, this forum has an excellent written recap tutorial

https://www.badcaps.net/forum/showthread.php?t=485

My son pointed out to me that we had a soldering iron. It is an Antex 25 Watts which I picked up for £5 from a local General DIY store not so long ago.

Attached are the JPGs.

Some questions:
(1) Is the wattage sufficient for it ot do the work that is required on the PCB i.e. de-solder and re-solder the CAPS; and

(2) Is the tip of sufficient shape and dimensions for it to be used for de-soldering and re-soldering work on a PCB?

Thanks.