Repairing Crossover 30Q5 PRO 30" monitor

[Specmaster]

I have been given this monitor as it had stopped working and I fancied playing around to see if I could get it working again thinking it was going to be a capacitor failed.

Plugged it in and it seemed to be dead apart from a blue power on indicator. A couple of seconds later there was a quick flash across the screen and the indicator turns red and the screen was dead.

Opened it up and took out the power distribution board and the video board, the other board is the back lights. Looking at the boards with a microscope it looked like some of the IC legs had tin whiskers growing on them and I also checked caps and all seemed to be OK but I did change one as it was unbranded but still checked OK.

I got my hot air gun and went over the board trying to get it hot enough to reflow the joints but nothing seemed to happen (dammed lead free solder), all the time  that I had fried the chips with the amount of heat there were getting blasted with.

After they had cooled down and checked under the microscope and the whiskers had gone, so put them back in the monitor and power up and scared that I fried everything but was surprised to be greeted with this screen. There is a FPGA on the video card and I'm wondering if the heat had reflowed some of the balls that make up the connections between board and chip?

Now, I don't know where else to go and what to do at this point as I cannot locate any information on this monitor on the web, so has anyone any ideas and advise that you could give me at all please?

[mnementh]

[Carried over from original response in TEA thread]

These are a Korean made "Bottom rung" niche market monitor made specifically to leverage the mid-side LG IPS displays into the $350-450 market niche. LOTS of variables here in this market segment; you have to pay extra for a "zero dead pixels" guarantee, and as you've found out, manufacturer service is vaporware.

What you're describing is high probability to be either a video processor or switcher IC fault (mainboard) or a T-con board (usually attached directly to the panel, between the panel and the LVDS cable to the mainboard). The T-Con and the panel are USUALLY sold as a matched pair; as in the T-Con is designed and firmware-specific to the particular panel. In many cases, even different product runs of the same panel will require a differently calibrated T-Con.

Fortunately, as the T-con is produced this way, you MAY be able to find a generic part by the LG Part no that will work most of the time but may have inaccurate color reproduction; in many cases these are pretty cheap and well-worth taking a gamble on resurrecting your screen.

Some screens may have an LED Driver between the mainboard and T-Con; this processes the LVDS signal to control the LED backlighting zones for dynamic contrast. It is usually a go/no-go part, but can kill all picture to the screen as well.


[EDIT] Almost 100% certain now; dead T-Con board. You'll want to check the power rails to the T-Con and make sure they're within spec before you change it. If you can find one. [/EDIT]


mnem
Needs more cowchip.

[neo]

This is just my opinion, but i think it's worth considering how far down the rabbit hole you want to go. It is definitely worth fixing, if it can be but the lead free solder, Korean origins and the magic mystery hour of problems would make me wonder.

That said will definitely be interesting to see what happens to it.

[Specmaster]

[Carried over from original response in TEA thread]

These are a Korean made "Bottom rung" niche market monitor made specifically to leverage the mid-side LG IPS displays into the $350-450 market niche. LOTS of variables here in this market segment; you have to pay extra for a "zero dead pixels" guarantee, and as you've found out, manufacturer service is vaporware.

What you're describing is high probability to be either a video processor or switcher IC fault (mainboard) or a T-con board (usually attached directly to the panel, between the panel and the LVDS cable to the mainboard). The T-Con and the panel are USUALLY sold as a matched pair; as in the T-Con is designed and firmware-specific to the particular panel. In many cases, even different product runs of the same panel will require a differently calibrated T-Con.

Fortunately, as the T-con is produced this way, you MAY be able to find a generic part by the LG Part no that will work most of the time but may have inaccurate color reproduction; in many cases these are pretty cheap and well-worth taking a gamble on resurrecting your screen.

Some screens may have an LED Driver between the mainboard and T-Con; this processes the LVDS signal to control the LED backlighting zones for dynamic contrast. It is usually a go/no-go part, but can kill all picture to the screen as well.


[EDIT] Almost 100% certain now; dead T-Con board. You'll want to check the power rails to the T-Con and make sure they're within spec before you change it. If you can find one. [/EDIT]


mnem
Needs more cowchip.

Here are 3 photos, not of the actual monitor but of one that I found a link to on the web, but mine is identical to this, the first one is of the thing with the back removed and shows the LVDS board at the bottom, the inverter for the screen lighting to the left and at the top under the cover is the T-Con board, the only other board that I can see in the bottom left corner (on the bottom) and holds the on/off switch and brightness up/down buttons all of which is working OK. I cannot see any other boards or leads disappearing off anywhere other then the 2 ribbon cables leaving the T-Con board and presumedly connecting to the screen?

The 2nd photo shows the T-Con board and the 3rd shows the Inverter.

[Specmaster]

This is just my opinion, but i think it's worth considering how far down the rabbit hole you want to go. It is definitely worth fixing, if it can be but the lead free solder, Korean origins and the magic mystery hour of problems would make me wonder.

That said will definitely be interesting to see what happens to it.

Yes, I think it would be good to save it if possible, make a great screen for schematics sat at the back of my bench while working on gear. It looks like its almost new, the case is all metal and there no visible scratches on it or the screen and Apple use the LG Panel on their high end systems calling it "Cinema" and costing £1100, Dell also use the same panel and it costs around £600 from them but it does demand a good graphics card because judging from what I can glean from the scant info on the makers web site it only has a native screen resolution of 2560 x 1600 fortunately, my card is capable of driving that. 

[mynameissteve]

Have you seen this? http://nand-hate.com/2015/11/crossover-30q5-pro-black-30-2560-x-1600-korean-ips-monitor-repair-notes/ I have the same monitor and had a capacitor blow in the power supply just the other day. I actually posted about it in the "beginner" thread, because it was my first time posting and it seemed more appropriate.


https://www.eevblog.com/forum/beginners/am-i-in-the-right-place-power-supply-capacitor-replacement/

Good luck!

[Specmaster]

Have you seen this? http://nand-hate.com/2015/11/crossover-30q5-pro-black-30-2560-x-1600-korean-ips-monitor-repair-notes/ I have the same monitor and had a capacitor blow in the power supply just the other day. I actually posted about it in the "beginner" thread, because it was my first time posting and it seemed more appropriate.


https://www.eevblog.com/forum/beginners/am-i-in-the-right-place-power-supply-capacitor-replacement/

Good luck!

Yes I did see that site thanks, thats where I got my photos from and I see he also had tin whiskers.

My power supply is similar to yours but there seems to be different versions, mine only has the illustration of a barrel plug with a centre pin positive but the monitor has a 4 pin mini din socket, strange.

[mnementh]

Since you have a pic that identifies all the main power rails, I'd start there with voltmeter and scope. Odds are a noisy/glitchy regulator killed the T-Con. I didn't realize this monitor was old enough to have CCFLs in it; once you get it fired up it may still not have proper color anyways as these high-brightness screens drive the CCFLs pretty hard and tend to fail by turning yellow then reddish.

Research a new T-con by the LG part number; you'll probably play hell finding it any other way.


Good hunting!


mnem
And Happy 2o18!

[Specmaster]

Since you have a pic that identifies all the main power rails, I'd start there with voltmeter and scope. Odds are a noisy/glitchy regulator killed the T-Con. I didn't realize this monitor was old enough to have CCFLs in it; once you get it fired up it may still not have proper color anyways as these high-brightness screens drive the CCFLs pretty hard and tend to fail by turning yellow then reddish.

Research a new T-con by the LG part number; you'll probably play hell finding it any other way.


Good hunting!


mnem
And Happy 2o18!

I have decided to start of with a total recap of the LVDS panel and the Inverter Panel, particularly as for the 30" screen requires 18V and yet there is 16V cap on that particular section.

It looks like there some of T-Con panels available but it does not look like the seller will send them to the UK or USA, other people are also apparently looking for the same panel and the general consensus is that maybe Apple have blocked it because they use the same LCD panel and T-Con panel and don't anyone breaking their strangle hold on the supply of parts? Seems possible as I heard many of unofficial apple repairers complain about will not allow them access to parts and schematics.

So far no success in locating a supplier of the LVDS panel should I need one of those.

[wraper]

If there were tin whiskers, you should wash the board in ultrasonic bath, or maybe just with some cleaning chemical. Not heat it without having appropriate equipment.

https://www.aliexpress.com/item/free-shipping-original-for-LG-LM300WQ5-SDA1-6870C-0314B-logic-board/32759694802.html?spm=2114.search0104.3.13.zp2cUJ&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10151_10065_10068_10344_10342_51102_10343_10340_10341_10084_10083_10307_10303_10302_10059_10314_10534_5790011_100031_10604_10103_10142,searchweb201603_40,ppcSwitch_7&algo_expid=c824583d-df22-4c1f-8525-fd388cc3199f-2&algo_pvid=c824583d-df22-4c1f-8525-fd388cc3199f&rmStoreLevelAB=5

https://www.aliexpress.com/item/LM300WQ5-SDA1-6870C-0314B-Logic-board/32825382638.html?spm=2114.search0104.3.7.zp2cUJ&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10151_10065_10068_10344_10342_51102_10343_10340_10341_10084_10083_10307_10303_10302_10059_10314_10534_5790011_100031_10604_10103_10142,searchweb201603_40,ppcSwitch_7&algo_expid=c824583d-df22-4c1f-8525-fd388cc3199f-1&algo_pvid=c824583d-df22-4c1f-8525-fd388cc3199f&rmStoreLevelAB=5

[Specmaster]

If there were tin whiskers, you should wash the board in ultrasonic bath, or maybe just with some cleaning chemical. Not heat it without having appropriate equipment.

https://www.aliexpress.com/item/free-shipping-original-for-LG-LM300WQ5-SDA1-6870C-0314B-logic-board/32759694802.html?spm=2114.search0104.3.13.zp2cUJ&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10151_10065_10068_10344_10342_51102_10343_10340_10341_10084_10083_10307_10303_10302_10059_10314_10534_5790011_100031_10604_10103_10142,searchweb201603_40,ppcSwitch_7&algo_expid=c824583d-df22-4c1f-8525-fd388cc3199f-2&algo_pvid=c824583d-df22-4c1f-8525-fd388cc3199f&rmStoreLevelAB=5

https://www.aliexpress.com/item/LM300WQ5-SDA1-6870C-0314B-Logic-board/32825382638.html?spm=2114.search0104.3.7.zp2cUJ&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10151_10065_10068_10344_10342_51102_10343_10340_10341_10084_10083_10307_10303_10302_10059_10314_10534_5790011_100031_10604_10103_10142,searchweb201603_40,ppcSwitch_7&algo_expid=c824583d-df22-4c1f-8525-fd388cc3199f-1&algo_pvid=c824583d-df22-4c1f-8525-fd388cc3199f&rmStoreLevelAB=5

Thank so much for these links.

[mnementh]

Since you have a pic that identifies all the main power rails, I'd start there with voltmeter and scope. Odds are a noisy/glitchy regulator killed the T-Con. I didn't realize this monitor was old enough to have CCFLs in it; once you get it fired up it may still not have proper color anyways as these high-brightness screens drive the CCFLs pretty hard and tend to fail by turning yellow then reddish.

Research a new T-con by the LG part number; you'll probably play hell finding it any other way.


Good hunting!


mnem
And Happy 2o18!

I have decided to start of with a total recap of the LVDS panel and the Inverter Panel, particularly as for the 30" screen requires 18V and yet there is 16V cap on that particular section.

It looks like there some of T-Con panels available but it does not look like the seller will send them to the UK or USA, other people are also apparently looking for the same panel and the general consensus is that maybe Apple have blocked it because they use the same LCD panel and T-Con panel and don't anyone breaking their strangle hold on the supply of parts? Seems possible as I heard many of unofficial apple repairers complain about will not allow them access to parts and schematics.

So far no success in locating a supplier of the LVDS panel should I need one of those.

Not likely any such evildoing on Apple's part; Apple wasn't able to stop LG from selling the original panels to your manufacturer in the first place.  As I've said before; there's enough real evil in the world without listening to haters who invent more just to have something to bitch about.

Much likelier, Apple discovered these were a high-failure part, so at some point bought out LG's entire stock of spares while there were still a sizable number of units out in the wild but still under Apple warranty. LG isn't interested in servicing 7-10 year old LCD panels OOW, they want to sell new panels; so market forces would tend to drive them to NOT produce spares that would cannibalize such future sales.

Remember... the logic of large-scale manufacturing has NOTHING to do with the logic of ordinary, real people in the real world. These are ALL people with MBAs or WORSE. Their daily operation is built upon a level of BS that would make any normal, sane person gag.

Good idea re: recapping all the power supplies. Dirty power and lack of cooling are the primary cause of failures in the T-con and video compression processing boards, which it looks like are combined into one on this model. You might also want to stick some heat sinks on the outside of the tin plate right where the processors have thermal pads; every 8-10° you drop operating temp here doubles the life of the chip.


mnem
No rest for the wicked.

[wraper]

30" LG panels never had a high failure rate. They had a lot of backlight bleed issues but not electronic failures. On the other hand, Samsung 30" panels of the same age had T-CON dying like cockroaches. They had Altera FPGA with the same BGA internal solder bump problem as NVIDIA GPUs.

[neo]

30" LG panels never had a high failure rate. They had a lot of backlight bleed issues but not electronic failures. On the other hand, Samsung 30" panels of the same age had T-CON dying like cockroaches. They had Altera FPGA with the same BGA internal solder bump problem as NVIDIA GPUs.

I can report that cockroaches have a very low fatality rate.

[Specmaster]

Not likely any such evildoing on Apple's part; Apple wasn't able to stop LG from selling the original panels to your manufacturer in the first place.  As I've said before; there's enough real evil in the world without listening to haters who invent more just to have something to bitch about.

mnem
No rest for the wicked.

These were new boards, not refurbished and the seller had plenty of them and judging by the long list of countries in his shipping list on the order form, it was to just about every other country you could think of but the notably missing ones was the USA and UK for some strange reason. I'm not so sure that it can be explained quite that simply as evil word of haters, my son used to work for the largest national chain of electronic and domestic products distributors in the UK and loves Apple but he tells me of some of the really anal things that Apple do and enforce with their distributors, things that are supposed to banned in most countries and yet they get away with it. 

Remember... the logic of large-scale manufacturing has NOTHING to do with the logic of ordinary, real people in the real world. These are ALL people with MBAs or WORSE. Their daily operation is built upon a level of BS that would make any normal, sane person gag.

mnem
No rest for the wicked.

Can't argue against that. 

Good idea re: recapping all the power supplies. Dirty power and lack of cooling are the primary cause of failures in the T-con and video compression processing boards, which it looks like are combined into one on this model. You might also want to stick some heat sinks on the outside of the tin plate right where the processors have thermal pads; every 8-10° you drop operating temp here doubles the life of the chip.


mnem
No rest for the wicked.

This is one of those areas where a good in circuit ESR meter would be so handy as all of these caps are of the aluminium SMD electrolytic type and its almost impossible to get sufficient heat onto the pads to melt the Pb free solder because the pads and contacts go under the caps. The only safe way of removing them without running the risk of lifting the pads, is to cut them off with side cutters and then apply heat to the centre of the pad to remove the legs. Obviously, this destroys the cap so you'll never know if it was good or not unless its showing signs of stress an started to spew its guts out on the board.

Turns out there are at least 2 sellers on AliExpress that sell these T-Con boards (new) at reasonable prices (thanks to wraper for the links) so if nothing doing after the recap (caps on order) I'll try one of those new boards, worth a try as the monitor has lots of good reviews under its other guises, Apple, Dell and I think HP.

Those additional heat sinks are a good idea providing there is enough clearance between them and the back metal casing, the 470uF 35v cap by the powerjack, was replaced by me for 470uF 50v one as the only one with a high enough voltage was too high and would not allow the case to be reassembled, so I had to replace it again and this time lay it sideways.

[wraper]

30" LG panels never had a high failure rate. They had a lot of backlight bleed issues but not electronic failures. On the other hand, Samsung 30" panels of the same age had T-CON dying like cockroaches. They had Altera FPGA with the same BGA internal solder bump problem as NVIDIA GPUs.

I can report that cockroaches have a very low fatality rate.

I can report that you fail to observe fatality rate because they have high replication rate.

[wraper]

Turns out there are at least 2 sellers on AliExpress that sell these T-Con boards (new) at reasonable prices (thanks to wraper for the links) so if nothing doing after the recap (caps on order) I'll try one of those new boards, worth a try as the monitor has lots of good reviews under its other guises, Apple, Dell and I think HP.

There is nearly zero chance they are new. And basically zero chance you can get a new board, especially for such price. This LCD panel is around 7 years old, you cannot expect any new boards to be still available.

[Specmaster]

Turns out there are at least 2 sellers on AliExpress that sell these T-Con boards (new) at reasonable prices (thanks to wraper for the links) so if nothing doing after the recap (caps on order) I'll try one of those new boards, worth a try as the monitor has lots of good reviews under its other guises, Apple, Dell and I think HP.

There is nearly zero chance they are new. And basically zero chance you can get a new board, especially for such price. This LCD panel is around 7 years old, you cannot expect any new boards to be still available.

Hmm, I assumed that they were new because there is zero there to suggest that these are equipment pulls or anything stating that they are used etc. I did notice that in one feedback it was mentioned that the item was used but worked well. Either way, if it works, if it turns out that I need one, I'll be happy with that.

[mnementh]

30" LG panels never had a high failure rate. They had a lot of backlight bleed issues but not electronic failures. On the other hand, Samsung 30" panels of the same age had T-CON dying like cockroaches. They had Altera FPGA with the same BGA internal solder bump problem as NVIDIA GPUs.

I can report that cockroaches have a very low fatality rate.

I can report that you fail to observe fatality rate because they have high replication rate.

SNARRFFF! 

You made me snort tea (not TEA) all over my keyboard. Fortunately, I learned the hard way and bought a washable one years ago. 

While these particular panels may not be high-failure, t-cons in general are a common failure item, and these are connected to a video signal source and power supplies that were of cheapest design and as many corners cut as possible. Plus this one appears to incorporate the video compression processing as well, so even more points of failure concentrated in a single board.

Agreed unlikely these are new at that price, unless somebody bought a containerload of them at a dockside auction that were lost for a few years... I've seen much weirder occurrences.

Apple does require some stuff of their supply chain that seems over the top... until you realize that their entire ecosystem and customer service ethic revolves around steering the customer towards replacement rather than repairing product. This is a plus to those who can afford it; you walk in with your busted, you walk out with new as good or better than you had.

They don't consider the time you have to spend setting up the replacement unit to be part of the equation; you're supposed to just be happy with the "new wonderful". Besides, if you fully buy into their ecology, pretty much anything you bring them can be restored onto a new unit from backup and you lose at most a day or three of your i-Life.

Again; the true Apple customer are folks who consider time to be more precious than money, and Apple caters to that mentality... and in reality, there is something to that point of view.

I've long said that money exists for one purpose; to allow the greedy to set their own price on another man's most precious resource - time.


mnem
"Run, don't walk away from anyone who says 'Time is money.' They grossly undervalue your time, and they do so only so they can rob you of it." ~me

[Specmaster]

SNARRFFF! 

You made me snort tea (not TEA) all over my keyboard. Fortunately, I learned the hard way and bought a washable one years ago. 

While these particular panels may not be high-failure, t-cons in general are a common failure item, and these are connected to a video signal source and power supplies that were of cheapest design and as many corners cut as possible. Plus this one appears to incorporate the video compression processing as well, so even more points of failure concentrated in a single board.

Agreed unlikely these are new at that price, unless somebody bought a containerload of them at a dockside auction that were lost for a few years... I've seen much weirder occurrences.

Apple does require some stuff of their supply chain that seems over the top... until you realize that their entire ecosystem and customer service ethic revolves around steering the customer towards replacement rather than repairing product. This is a plus to those who can afford it; you walk in with your busted, you walk out with new as good or better than you had.

They don't consider the time you have to spend setting up the replacement unit to be part of the equation; you're supposed to just be happy with the "new wonderful". Besides, if you fully buy into their ecology, pretty much anything you bring them can be restored onto a new unit from backup and you lose at most a day or three of your i-Life.

Again; the true Apple customer are folks who consider time to be more precious than money, and Apple caters to that mentality... and in reality, there is something to that point of view.

I've long said that money exists for one purpose; to allow the greedy to set their own price on another man's most precious resource - time.


mnem
"Run, don't walk away from anyone who says 'Time is money.' They grossly undervalue your time, and they do so only so they can rob you of it." ~me

How very true, I think that you've summed up the whole Apple ethos nicely there which for those of us who are wealthy enough to be able to afford to accept that, its OK. Trouble is however that there are those that see these people as role models and they desperately want to be seen as being upwardly mobile and either get into debt to be able to have the Apple products with their upmarket image, or are prepared to commit crimes in order to acquire them.

It was not that many years ago that the UK police had a problem with the number of youths that were snatching high end phones, especially iPhones out of peoples hands and making off with them on bikes, in fact I believe it started with iPods and the iconic white ear buds which gave them away. IIRC there was even advice issued to keep your white ear buds for indoor use and get a cheap pair of black ear buds which normally signalled that you only had a cheap and lowly MP3 player.

mnem
"Run, don't walk away from anyone who says 'Time is money.' They grossly undervalue your time, and they do so only so they can rob you of it." ~me

[Specmaster]

Update, all recapped and power rails would appear to be correct so its looking increasingly like the T-Conn board is at fault, so just about to order one from AliExpress and then have to wait for it crawl its way to me. 

EDIT, T-Conn board is on order, fingers crossed that cures it brings this monitor back to life again.

[Specmaster]

Turns out there are at least 2 sellers on AliExpress that sell these T-Con boards (new) at reasonable prices (thanks to wraper for the links) so if nothing doing after the recap (caps on order) I'll try one of those new boards, worth a try as the monitor has lots of good reviews under its other guises, Apple, Dell and I think HP.

There is nearly zero chance they are new. And basically zero chance you can get a new board, especially for such price. This LCD panel is around 7 years old, you cannot expect any new boards to be still available.

Well I've ordered a board from AliExpress and I understand that it will be on it's way to me soon. Hopefully it will work OK and I'll have a working monitor again.

[Specmaster]

Just had an email informing that the T-Conn board has today finally been shipped, so it be at least 2 weeks before I get it. Just that hope it is the correct one and it works and cures my problem. Time will tell.

[Specmaster]

Here's the latest tracking info on my T-Conn board for this monitor WTF is going on here?

[wraper]

It means that item was never dispatched. Recommended solution is waiting till protection time will end in like a week and open the dispute. Opening dispute early may result in loosing it. Of course you can contact the seller and ask why item was not dispatched.