Asus VK266H Monitor rebuild.

[stj]

Re: Asus VK266H Monitor rebuild.

i would avoid that, you dont know the series of caps or if they are fakes.

[SpiderWaffle]

Re: Asus VK266H Monitor rebuild.

Alright, Actually I think I can get them cheaper going through digi-key so long as the shipping isn't too much. Question about how "good" of caps to get though:
of all the compatible 680uF 10,000 hr caps, price ranges from $.55 to $.95 with respective ratings of 25V, 968mA, 28 mOhm and 35v, 2.9A, 17 mOhm.

http://www.digikey.com/product-detai...855-ND/3563722
http://www.digikey.com/product-detai...930-ND/3664393

And everything in between.

Is there a rule thumb people follow when replacing caps like this?

(there's easily 30+mm of clearance on the height)

[momaka]

Re: Asus VK266H Monitor rebuild.

Alright, Actually I think I can get them cheaper going through digi-key so long as the shipping isn't too much.

Probably $4-6 at most for a small order, if even that. It's been a few years since I bought anything from there, though, so prices may have increased a bit (inflation?)

of all the compatible 680uF 10,000 hr caps, price ranges from $.55 to $.95 with respective ratings of 25V, 968mA, 28 mOhm and 35v, 2.9A, 17 mOhm.

http://www.digikey.com/product-detai...855-ND/3563722
http://www.digikey.com/product-detai...930-ND/3664393

And everything in between.

Is there a rule thumb people follow when replacing caps like this?

Generally, you try to match the ESR and ripple current of the old caps, along with rated capacitance and voltage. Usually in this manner:
- rated voltage of new capacitor should be the same or higher than original
- rated capacitance of new capacitor should be the same or higher (but one notch lower will also work in most cases, though I don't recommend it unless you have no alternative)
- ESR of new capacitor should be the same or lower than original (slightly higher ESR may also work in most cases, but just not recommended unless you have no other choice)
- ripple current of new capacitor should be the same or higher than original (slightly lower ripple current may also work in most cases, but just not recommended unless you have no other choice)

The Nichicon HW and Rubycon ZLH you posted should work fine. And many of the series I mentioned in post #17 should be okay.

[SpiderWaffle]

Re: Asus VK266H Monitor rebuild.

Generally, you try to match the ESR and ripple current of the old caps, along with rated capacitance and voltage. Usually in this manner:
- rated voltage of new capacitor should be the same or higher than original
- rated capacitance of new capacitor should be the same or higher (but one notch lower will also work in most cases, though I don't recommend it unless you have no alternative)
- ESR of new capacitor should be the same or lower than original (slightly higher ESR may also work in most cases, but just not recommended unless you have no other choice)
- ripple current of new capacitor should be the same or higher than original (slightly lower ripple current may also work in most cases, but just not recommended unless you have no other choice)

I've gathered as much, but unfortunately I've failed to find such any way to decipher the model number of these elite capacitors and any of their ratings beyond the capacitance and voltage. (or max operating temperate)

but you think 968mA and 28 mOhm is good enough?
if that's fine I might just go with this 1.238A 18 mOhm also 35v one for 8 cents more and go with 1 better than than the worst compatible 10,000 hr cap for all the rest of them like that too.
http://www.digikey.com/product-detai...749-ND/3563861

[rugger]

Re: Asus VK266H Monitor rebuild.

I'd done a few monitor recaps using the Rubycon ZLJ caps without issue. The ZLH should be be pretty compatible as well.

[SpiderWaffle]

Re: Asus VK266H Monitor rebuild.

Anyone else had issue with finding a cap to replace the one 8mm 470 uF 16v cap on the main board?
Digi-key doesn't have any such 8mm with 10,000 hours, only two 9,000 hours are these:
http://www.digikey.com/product-detai...205-ND/3563388
http://www.digikey.com/product-detai...237-ND/4847233

the united-chem having the much better ripple current rating but unknown minimum temperature (though probably not a problem in SoCal)

I was thinking I could just get a 10mm instead, it's currently sitting up at an angle with 5mm leads anyway. Has anyone done that before?

[stj]

Re: Asus VK266H Monitor rebuild.

unless your operating outdoors at the northern end of norway/sweden or in alaska, the minimum temp is irelevent!

[SpiderWaffle]

Re: Asus VK266H Monitor rebuild.

I think I've found all good caps to do full replacement of all 23 caps, do these all look compatible:

http://www.digikey.com/scripts/DkSea...30682612813298
http://www.digikey.com/scripts/DkSea...30682612813298
http://www.digikey.com/scripts/DkSea...30682612823299
http://www.digikey.com/scripts/DkSea...30682612823299
http://www.digikey.com/scripts/DkSea...30682612823299
http://www.digikey.com/scripts/DkSea...30682612833300
http://www.digikey.com/scripts/DkSea...30682612833300
http://www.digikey.com/scripts/DkSea...30682612843301

http://www.digikey.com/scripts/DkSea...30682612833300
(only 9,000 hrs) or this one below that mouser offers in min. order of 1
http://www.mouser.com/ProductDetail/...yBv5Zoxg%3D%3D

I'll have to fan out the two 220uF ones a little bit for being 8mm instead of 6.3mm, and maybe one of the 100uF ones for being 6.3mm instead of 5mm.
There shouldn't be any issue with impedance being too LOW for this type of circuitry right?

[sghill99]

Re: Asus VK266H Monitor rebuild.

i would avoid that, you dont know the series of caps or if they are fakes.

They aren't fakes..., only Panasonic (FR, FM, or FC in that order, or Nichicon, PW)... FYI...

[donmus]

Re: Asus VK266H Monitor rebuild.

Fantastic ! ça a marché pour mon ASUS VW266H....
J'ai changé tous les condensateurs électrolitiques du power supply et également ceux du main board logic .....donc Javais 2 problèmes ---(Power supply et logic board).

It's worked for me.....yes !!!!
Fan-tas-tic ! it worked for my ASUS VW266H ....
I changed all the electrolitic capacitors of the power supply and also those of the main logic main board ..... so I had 2 problems --- (power supply and logic board).
tanks everybody !!!

[rusefi]

Re: Asus VK266H Monitor rebuild.

Just to add into the collection https://www.youtube.com/watch?v=v8hioaCwkZo

I know all 9 are equally poor quality but I wonder if schematics on 31 gives enough data to attempt a partial fix?

Used boards on eBay are about $30, for that money I can attempt replacing maybe three caps but not 9 mouser shipping free since I have to place a different order anyway.

[dapug]

Re: Asus VK266H Monitor rebuild.

I've replaced all 9 caps with high quality Rubycon caps from Digikey, all correct values. NO LOVE. Exactly the same warm-up issue on power up, which takes SEVERAL minutes at this point before it clears up, been getting worse and worse over time.

So... what else could it be?

[momaka]

Re: Asus VK266H Monitor rebuild.

I've replaced all 9 caps with high quality Rubycon caps from Digikey, all correct values. NO LOVE. Exactly the same warm-up issue on power up, which takes SEVERAL minutes at this point before it clears up, been getting worse and worse over time.

Is it the same issue like in the video shown above by rusefi?

If so, that could be due to bad caps on the logic board.
Or, it could also be TFT tab bonds getting bad (those thin flex-cables that connect between T-con on top of the monitor and the TFT panel of the monitor.)

If the issue is the former, new caps for the logic board should solve that issue.
If it's the latter, monitor is probably just running on borrowed time at this point.

Can't know for sure, though. I suggest posting pictures of your logic board and maybe checking the voltages on the LDO regulators there.

[dapug]

Re: Asus VK266H Monitor rebuild.

Is it the same issue like in the video shown above by rusefi?

If so, that could be due to bad caps on the logic board...

Yes, it is exactly that issue as seen in the video. But this whole thread aims at replacing caps of the PSU. I did that. And though I haven't replaced them all on the logic board, none look damaged, and nobody else has mentioned that as the issue.

Sigh. I guess I could did through the main board and start identifying those caps. At this point I'm not sure how much more effort and $ I want to pour into this.

[momaka]

Re: Asus VK266H Monitor rebuild.

But this whole thread aims at replacing caps of the PSU. I did that. And though I haven't replaced them all on the logic board, none look damaged, and nobody else has mentioned that as the issue.

Yeah, caps on the logic board usually tend to make it longer than on the PSU board, due to not being under as much stress. However, there are certain monitors where this has been a recurring issue before (e.g. the Hanns-G HG281-D.) So when in doubt, I now usually suggest to recap both, since caps are relatively cheap (and saves you on having to pay for shipping twice, should the caps on the logic board turn out to be bad.)

Also, caps don't have to look bulged and/or leaking to be bad. In fact, high-heat stress on small caps (like the ones on your logic board) usually tends to make their electrolyte dry out over time... and that will cause the caps to go bad (high ESR and/or low capacitance) without showing any external signs.

At this point I'm not sure how much more effort and $ I want to pour into this.

Understandable.

The price of LCD monitors and TVs (both new and used) has really gone down quite a lot, making it hard to justify repairs on an old monitor.

So on that note, you be the judge what you should do in your situation. If you're doing the repair just for fun and/or to learn, then don't let the above discourage you from trying to finish the repair. On the other hand, if your time is limited, doing this repair to save $$ may not be the most worthwhile. Moreover, there is also a chance this issue with the screen showing random artifacts at startup could be due to failing tab bonds between the TFT and T-con... and if that's the case, there isn't much that can be done to fix it. So there is a chance new caps on the logic board may not fix the issue. But again, depending on your situation, getting new caps for the logic board may or may not be worthwhile to try next.

[dapug]

Re: Asus VK266H Monitor rebuild.

The price of LCD monitors and TVs (both new and used) has really gone down quite a lot, making it hard to justify repairs on an old monitor.

Indeed. I've been looking for an excuse to upgrade, and literally just bought two 27" frameless monitors. Been needing that for work for a while.

Meanwhile, I wrote down the values of the logic board caps, and while I wont make a special order for it, next time I need components for some other project, I'll include these caps and give it a go.

...there is also a chance this issue with the screen showing random artifacts at startup could be due to failing tab bonds between the TFT and T-con... and if that's the case, there isn't much that can be done to fix it.

Hope not. But yes, it's worth swapping the caps on the logic board as a final effort before I completely dump this monitor.

[momaka]

Re: Asus VK266H Monitor rebuild.

Meanwhile, I wrote down the values of the logic board caps, and while I wont make a special order for it, next time I need components for some other project, I'll include these caps and give it a go.

Yeah, that's what I do with a lot of my projects that aren't really worthwhile by themselves, but still worthwhile enough to try and maybe learn something from it.

I've gotten a lot of monitors like that from my local Craigslist, and managed to get a good number of them fixed. Learned something new from a couple of them too.

Anyways, let us know how it goes or if anything else comes up.