SyncMaster B2330 Flickers, Floods white, Goes black

[Madman58368]

I have searched high and low and have yet to find anyone describing a problem that sounds like mine. Maybe I am not defining the problem well when I do my searches, so here I am asking for your help.
This monitor was given to me by my cousin because it is just outside it's factory warranty and he didn't want to throw it out.
I have tested it with both the VGA and the DVI-D connections on 3 different systems and it behaves the same no matter what.
For the first 3 to 5 minutes it works flawlessly, then it starts to flicker like an old TV when the V-Hold was slipping, everything freezes, then the top right corner turns white and floods the whole screen white for a few seconds before it all goes black.
I already took the boards out and visually inspected them. Nothing appears to be out of the ordinary. I haven't yet tested any components because I am not sure which ones I should test or what the readings should be. I did read the "how to test a voltage regulator" post in the FAQ. I have a quality digital multimeter and would be comfortable testing anything at all if someone can tell me which components are the most likely suspects, and give me the first timers guide to properly testing them and looking up their data sheets.
I'll attach some pictures, and if you need better quality or more information just let me know, I'll be checking in after work tomorrow.
Thanks in advance for any help here.
Madman

[selldoor]

Re: SyncMaster B2330 Flickers, Floods white, Goes black

Wow! that is one of the best first posts I have seen for some time.
The pictures are not really clear enough for troubleshooting - when enlarged we need to be able to read the part numbers that are on the board- good light (without flash)is the key to good pictures.
First thing might be to read this guide to 2 sec to black by retiredcaps- I dont think it is your problem but the tests will be similar. start at post19 https://www.badcaps.net/forum/showthread.php?t=10419. While reading try to find the components on the boards.
Any your not sure about google it then select images , should help. Still stuck - ask.

If it is currently all set up switch it on and try heating gently with a hairdryer, to see if
you can make it go off quicker. Start with the power supply warm the whole board.
If it does fault quicker let it cool then do it again trying to pinpoint a section of the board.
If it doesnt then move on the the main board. I Think you should also have another board in there - the tcon or panel board. lastly try that.

On the first picture there are two main voltage regulators one at U101 three legs and a tab and another on the right hand top of the same board.
Test and post result with the part number.

Another quick test is check the ribbon cable between the main board and panel board
It may it may just move slightly when it gets hot and could cause the problem you have.
Try cleaning and reseating that first

[Davi.p]

Re: SyncMaster B2330 Flickers, Floods white, Goes black

I would test the p. supply in this way, not with hairdryer first but wait until with monitor ON it starts with flaws, then measure outputs in the supply. After this test vcc voltage before and after the lvds cable. If you cannot, post a picture of the tcon board.

[Madman58368]

Re: SyncMaster B2330 Flickers, Floods white, Goes black

My regular work schedule is Friday, Saturday and Sunday, 6am to 6PM, so I will have to look into this more on Monday. Thank you for helping out so quickly.
Davi.p- quick newbie question, what is the vcc voltage, and what is the lvds cable?

[Davi.p]

Re: SyncMaster B2330 Flickers, Floods white, Goes black

Vcc are those pins that conduct the power supply, for the panel is 5v, you can recognize them becouse are those 3 pins connected toghether at the side of the lvds connector, the lvds is a flat conection of about 30 tracks that goes from Main logic Board to Panel Tcon board.

[Madman58368]

Re: SyncMaster B2330 Flickers, Floods white, Goes black

After using some powerful magnification goggles to go over all the solder joints on all 3 boards, I repaired a few and fired it up. It took about 5 minutes before it started getting horizontal lines and started to flicker, then everything froze and when I ran my mouse over to that screen it didn't show up. About 30 seconds after the display froze up it went black but I can still see some white lines and a kind of white square. I am attaching a photo of what I am seeing right now. While it is powered up and in its failed state I am going to check out the things suggested by Davi.p.

[Madman58368]

Re: SyncMaster B2330 Flickers, Floods white, Goes black

Okay so I tested 2 voltage regulators. My head aches from the goggles I had to wear to read the tiny little numbers on these things. maybe I'll invest in one of those x100 USB microscopes I saw someplace.
the one at U101 is
FSP2150B
J1005h2
pin1 -0.01
pin2 3.28
pin3 5.03
The one at U102 is
FSP2160B
c1003H1
pin1 -0.01
pin2 1.76
pin3 3.27
I am having a little trouble locating a data sheet for the first one. The second one I found with a google search and the second pin is 0.04V lower than it should be. I may be new to this and horribly unprepared for this undertaking but I will not give up! The numbers on the voltage regulator at U102 didn't turn out in the pic so well so I had to use paint to help out a little.

[Th3_uN1Qu3]

Re: SyncMaster B2330 Flickers, Floods white, Goes black

Replace the capacitors at the outputs of those voltage regulators first. If it still does the same, replace the regulator that reads 1.76v. I've seen this before and it's the 1.8v rail at fault. Either the cap or the reg.

[Madman58368]

Re: SyncMaster B2330 Flickers, Floods white, Goes black

Th3_uN1Qu3, I have replaced the three caps indicated in the first photo below. It is still giving me the same trouble except that when it fails all I have to do is turn the power off for a second then turn it back on and it is fine for another few minutes before it fails in the same way. When I was at my local electronic parts store I went ahead and bought the capacitors to replace the ones I circled in green in the second photo. Should I proceed with that or do you think it is something else?

[selldoor]

Re: SyncMaster B2330 Flickers, Floods white, Goes black

What make series caps did you buy? -may not be suitable.

If you have bought new ones you maqy as well try replacing - also try an source
a new voltage regulator.

[Davi.p]

Re: SyncMaster B2330 Flickers, Floods white, Goes black

I hope i will not confuse anymore, but i remember a little when i was repairing that benq with the same common issue in the inverter area, i had replaced one power mosfet, the one that feeds to the "buck-royer" circuit (or is part of it), it has the inverter power supply line on the source pin, it had been sold to me with a defect, it had a small piece of metal that connected 2 pins, the screen behavior was similar apart the flicker part.

[Madman58368]

Re: SyncMaster B2330 Flickers, Floods white, Goes black

What make series caps did you buy? -may not be suitable.

If you have bought new ones you may as well try replacing - also try an source
a new voltage regulator.

The local electronic supply store sold me NTE 105*C +/- 20%. Knowing very little about this I didn't think to ask questions at the shop, I was to eager to get home and break out the soldering iron and get to work.

[selldoor]

Re: SyncMaster B2330 Flickers, Floods white, Goes black

NTE are general purpose caps not really suitable - you should try to find low esr caps
usually means digikey - panasonic fr fm or fc or nichicon or rubycon equivalents

[Davi.p]

Re: SyncMaster B2330 Flickers, Floods white, Goes black

Cancelled