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**retiredcaps** · 05-28-2010, 03:28 PM

Re: ViewSonic VX924 - The Saga Continues

What brand/make are the replacement caps?

Can you be more specific in the screen flicking on/off? Does it stay off/on for a certain period? Do the power LEDs on the front change color?

Also post pics of both side of the board after reading the FAQ on how to insert pics.

There are a number of suggestions on the Net how to remove a bald screw.

Originally posted by gosnis

Using my new found knowledge, I successfully replaced all the Caps in the power/inverter board of my ViewSonic VX924 monitor.
However, after doing so the symptoms persisted (screen flicking on and off).
So I then decided to replace the power/inverter board with a new one via China.
Only to find that this didn't fix the issue.

Does anyone have any ideas as to what I can do next?
I assume it might be the logic board which is at fault,
this I have not touched.
The main reason for this is I couldn't get to it properly due to bald screws.

**gosnis** · 05-29-2010, 04:12 AM

Re: ViewSonic VX924 - The Saga Continues

Hi there retiredcaps,
Thanks for the quick response.

Regarding the symptom:
The monitor seems to go to standby/sleep mode randomly.
I can turn it on again, but it will turn itself off again randomly.
Some times it will turn itself off and back on, either once or multiple times.
When it is turned on, the power light should be green,
but it is orange all the time now. Orange is for standby!

Regarding the new caps:
The Caps I used on the original power board were a mix of Panasonic and Rubycon, purchased from a reputable UK seller.
But I have now replaced the original power board with a new/used one,
as pictured.

I was unable to upload the photos to your server using FAQs details,
so have hosted them else where.

Power Board Pics:

Logic Board Pics:

Hope the above images are OK.

Thanks again,
Tony.

Attached Files

**Scenic** · 05-29-2010, 04:58 AM

Re: ViewSonic VX924 - The Saga Continues

got a 12V powersupply with at least 1.5A handy? (2.5+A would be better)
if so, you could "inject" it to the pinheader connecting the powersupply/inverter board to the logic board.
or just solder 2 wires with the right polarity to the cap right next to the pin header.

that way you can determine if the logic board is OK or not and make sure it's not the power/inverterboard's fault.
if it still randomly goes into standby mode, it's most likely the logicboard.

identical PSU/inverter board as in the Belinea 101910 and the viewsonic VX910 (and possibly a lot more monitors)
https://www.badcaps.net/forum/showpo...9&postcount=11

**gosnis** · 05-31-2010, 06:50 AM

Re: ViewSonic VX924 - The Saga Continues

Hi Scenic,
Thanks for the reply.
I think I have a low powered CB Radio power supply knocking around,
that should be around 12-13v and 2-3.5 Amp.
I will have a look for it today and get back to you after testing.

Many thanks
Tony.

**Scenic** · 05-31-2010, 06:54 AM

Re: ViewSonic VX924 - The Saga Continues

if you're really hardcore you could also use the 12V from your computer's molex plugs (yellow + black -)

not recommended though unless you know what you're doing (risk of releasing the magic smoke

)

**gosnis** · 06-01-2010, 08:19 AM

Re: ViewSonic VX924 - The Saga Continues

Originally posted by Scenic

if you're really hardcore you could also use the 12V from your computer's molex plugs (yellow + black -)

not recommended though unless you know what you're doing (risk of releasing the magic smoke

)

Even better, I have a couple of PCs lying around,
so I will use a power supply via molex from one of them.

So to confirm;
I connect my yellow+ and black-,
to the cap right next to the pin header,
remembering to connect the correct polarity.

Only thing i need to do now is find some suitable wire for the job.
I might cut up a molex splitter i have, that'll do it.

Will let you know how i get on.

**robert** · 06-01-2010, 11:07 AM

Re: ViewSonic VX924 - The Saga Continues

This board looks very familiar to me.
Maxdata/Belinea 19" TFTs use the exact same one. I repaired many of these, Sucess rate was high.
Caps: Throw out each any any on the PSU. Ive used Rubycon ZL 470/25V, Rubycon AXW (later Panasonic ED) 100/400V, and Rubycon YXF for the small one.
For the logic board, replaced the large Teapo with 470/25V ZL as well.

The small cap on the PSU board (iirc 47u) is dry usually, and causes the PSU to do strange things like not starting or sometiomes shutting off !!
Also resolder every large component, especially the power transistors/diodes. FSP typical RoHS soldering, cracks all the time.

Had one that was shot, Fuse blown on the PSU board, as well as the bridge rectifier.
Didnt work after replacement, more testing showed the transformer primary was burned open, so thats it.

Repaired it for my own use though, that is rempoving all pri side components from the PSU and install a connector for 12V DC power (needs about 4-4.5A, so use a suitably rated power supply).
Cant give something like this to customers for reasons of liability, so this is only for personal use.

**Scenic** · 06-01-2010, 11:25 AM

Re: ViewSonic VX924 - The Saga Continues

4 - 4.5A ?
wtf are you smoking?

i'm using one with a (already oversized) 3.75A PSU.
the max. the original one does is 3A, nominal 2.75A
(hence the name.. FSP035-xxxx .. 35W max. output)

**robert** · 06-01-2010, 11:33 AM

Re: ViewSonic VX924 - The Saga Continues

Mine draws about 4A on startup and 3.3-3.4A on full brightness.
Could be that Maxdata uses higher power backlight then Viewsonic.
Heatsinks on the PSU are somewhat larger on the maxdata, even though the board is identical (and often discolored heavily around the transformer and over the CCFL inverter transistors)
Maxdata did use a Rubycon on the logic board in some of the ones i repaired, too. Doesnt help if the CrapXon in the PSU fails, though.

Also, for these external power supplies, dont load them more then 85% of their rating, or expect them to get hot and die soon. Usually full of Capxon or Teapo (or worse)...
thats the one with the cooked transformer:

Attached Files

**Scenic** · 06-01-2010, 12:07 PM

Re: ViewSonic VX924 - The Saga Continues

brightness on mine is never above 40.. that's just way too bright to work with for a longer time period.

the external PSU is recapped with Panny FC's.
been using this setup for more than a year now.. zero probs.

**gosnis** · 06-01-2010, 01:32 PM

Re: ViewSonic VX924 - The Saga Continues

So to confirm;
I connect my yellow+ and black-,
to the cap right next to the pin header,
remembering to connect the correct polarity.

And if this works OK, I could continue to use the setup indefinitely?

Cheers,
T.

**jeb007** · 06-21-2010, 04:51 AM

Re: ViewSonic VX924 - The Saga Continues

Hello.. I hope someone can clarify.. I folllowed the info form SCENIC .got a 12V powersupply with at least 1.5A handy? (2.5+A would be better)
if so, you could "inject" it to the pinheader connecting the powersupply/inverter board to the logic board.
or just solder 2 wires with the right polarity to the cap right next to the pin header.

that way you can determine if the logic board is OK or not and make sure it's not the power/inverterboard's fault.
if it still randomly goes into standby mode, it's most likely the logicboard.<<

In my situation it did make the screen light up but then went blank again.( loops every 6 seconds ) Does this mean it is a fault somewhere on the Logic board or is it on the Invertor board. I have disconnected the primary components of the PSU The Power part of the board also has a problem which I can sort later

All the CAPs look good from the top but I have not removed any yet. Any guidence from experance wouold be appreciate before I remove all the caps and still find it will not work,, Thanks John

**gosnis** · 01-10-2011, 07:27 AM

Re: ViewSonic VX924 - The Saga Continues

Originally posted by Scenic View Post

got a 12V powersupply with at least 1.5A handy? (2.5+A would be better)
if so, you could "inject" it to the pinheader connecting the powersupply/inverter board to the logic board.
or just solder 2 wires with the right polarity to the cap right next to the pin header.

that way you can determine if the logic board is OK or not and make sure it's not the power/inverterboard's fault.
if it still randomly goes into standby mode, it's most likely the logicboard.

identical PSU/inverter board as in the Belinea 101910 and the viewsonic VX910 (and possibly a lot more monitors)
https://www.badcaps.net/forum/showpo...9&postcount=11

Hi all. after many months I thought I'd update this thread.
I lost my patience trying to fix the monitor and purchased a new one.
However, I just tried Scenic's suggestion and "injected" a 12V feed via a CB power pack. Which seems to be working sweet.

Thanks for the input Scenic, much appreciated.
The annoying is, i replaced all caps on the original board,
then purchased a used one from china which still didnt work.
But you live and learn and it works now, fantastic.

**gosnis** · 01-10-2011, 04:13 PM

Re: ViewSonic VX924 - The Saga Continues

Originally posted by gosnis View Post

Hi all. after many months I thought I'd update this thread.
I lost my patience trying to fix the monitor and purchased a new one.
However, I just tried Scenic's suggestion and "injected" a 12V feed via a CB power pack. Which seems to be working sweet.

Thanks for the input Scenic, much appreciated.
The annoying is, i replaced all caps on the original board,
then purchased a used one from china which still didnt work.
But you live and learn and it works now, fantastic.

News update.
I didnt work after all.
The screen goes blank after a while, then keeps going blank.
Never mind, at least I've learned a few thing and polished my soldering skills.

Thanks for the help anyway guys.

**gosnis** · 01-16-2011, 02:25 PM

Re: ViewSonic VX924 - The Saga Continues

So, seeing as the power-board is not the issue,
is it likely the logic board at fault, and if so can this be replaced easily??

G.

**polarys425** · 04-29-2011, 10:57 PM

Re: ViewSonic VX924 - The Saga Continues

Have you replaced any capacitors on the logic board? IIRC i have had to replace them on both the power and logic boards.

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