Viewsonic VA912b messed up display

[marco916]

Re: Viewsonic VA912b messed up display

Sounds like a plan, I've never replaced caps on a board, but have replaced power supplys on LCD's, seems pretty straight forward, just have to keep track of all your screws (:

[marco916]

Re: Viewsonic VA912b messed up display

Ohh and By the way, Hello everyone, not new to Badcaps, but new to this forum.

[PlainBill]

Re: Viewsonic VA912b messed up display

As a reference, there is a company on eBay that will repair your power supply for $35, plus it'll cost another $5 to ship it to them. It'll cost about $10 to get the parts to repair it yourself.

A couple of tricks I use when tearing these down. Use an egg carton to hold the screws; identify where each group of screws came from. And if the monitor is going to sit in pieces for more than a day, I put all the screws in baggies labeled with the location. This way the screws don't get scrambled when someone decides to straighten up the area.

I still remember fondly a Sharp fax machine I repaired many years ago. The only problem - the fuse blew. It was soldered in place and about two dozen screws had to be removed to get to it. Some gracious engineer designed that fax machine so EVERY screw was identical.

PlainBill

[marco916]

Re: Viewsonic VA912b messed up display

Hey guys, I was finally able to muscle open the ViewSonic today "or should I say HannStar who actually makes the screen", LCD dosne't really have that many screws to undo, its mostly a snap together plastic bezel and few screws holding down the power supply and video inputs. I snapped a few photos of the power supply, let me know what you think.

[EGuevarae]

Re: Viewsonic VA912b messed up display

Hey guys, I was finally able to muscle open the ViewSonic today "or should I say HannStar who actually makes the screen", LCD dosne't really have that many screws to undo, its mostly a snap together plastic bezel and few screws holding down the power supply and video inputs. I snapped a few photos of the power supply, let me know what you think.

Bulged capxons all over the place. Replace them with the PCBONEZ suggested caps.

[marco916]

Re: Viewsonic VA912b messed up display

thanks for the info

[kerm007]

Re: Viewsonic VA912b messed up display

hi
i got the same issue but wondering how to take apart the monitor without breaking everything ? i can see 4 screws at the back but how to remove the plastic cover ?

Thanks

[TBoneit]

Re: Viewsonic VA912b messed up display

Should work the same for yours/

Getting it open is a pain -- four screws on the corners to remove, then force a metal spatula between the silver surround and the back of the case. There are about half a dozen clips holding it together -- unlock a corner first, then work your way around.

Snipped

If this doesn't fix the monitor, stare daggers at the Teapo capacitors on the driver board. Don't replace these unless you absolutely have to -- the PCB is multilayer (appears to be 4-layer, possibly more) was designed without thermal reliefs, so soldering the grounds on the capacitors is incredibly difficult. I replaced these as well, because I'm a glutton for punishment

Reassembly is, as the saying goes, the reverse of disassembly
- Phil.

I did have to replace the two 330Uf capacitors on the driver board as they were starting to bulge. I only had 470Uf in the proper voltage rating. The 400Volt 100Uf in the power supply is just starting to bulge. That one I'll have to order.

It is now working fine despite needing the 400Volt cap. I put it back together to test before ordering the 400V 100uf since if it was dead no sense spending the money.

I'm a little surprised since in the past it was thought that Viewsonic was a good brand.

Thanks to Phil for the disassembly instructions.

Cheers

[Devo-san]

Re: Viewsonic VA912b messed up display

I kinda hate to revive an old post but it was the most informative and I had referenced it for 2 VA912b's that I found in my pile.

I thought I should mention that parts will vary because Viewsonic uses a multiple number of vendors. I cracked open both monitors thinking I had all the caps on hand only to discover I needed a completely different set (1000mF 25v, 2200mF-10v, and 3900mF - all leaking/bulging).

Having a completely different power supply wasn't surprising to me. It was the fact that the monitor power supplies I had were made by Delta Electronics, an Old School (40+ years) power supply company. Worse, they too used the same POS CapxOff (CapXon) crap causing problems everywhere (using the same KF series as mentioned before).

I'm a little surprised since in the past it was thought that Viewsonic was a good brand.

These days it is hard to point fingers. Everyone uses the same panels made by the handful of companies that manufacture them and either use a reference design or slightly modified logic board to run them. Buying OEM off the shelf power supplies, in a way, is cost cutting but a good thing to keep everything modular. In my sitch, after 40+ years Delta should have figured out how to make a good power supply but apparently they too have penny pinched a inferior product.

Remember that scene in Armageddon?

"American spacecraft... Russian spacecraft... All made the same. All made in Taiwan".

...or from a subsidiary in Red China where they are trying to adjust to human rights that alone tooling up for quality capacitors. ...but I digress. Capacitor replacement can be a profitable (or productive) business so gotta love the (new Capitalist-)Commies. =D