Samsung SyncMaster 204B

[tuo]

Hi,

I have a failing Samsung SyncMaster 204B. I know that Dave did a repair video on this monitor several years back, where he did swap the capacitors to new ones. And I have actually done that already more than two years ago swapping the old CapXons to Panasonic ones, as the monitor was failing the first time. So now when the picture sometimes seems to be colorless or lacking one color or the monitor is not starting properly, I thought that I would be the big primary side cap, that is now dying. But there was no bulging to be seen on it and after I swapped that one to Nippon Chemicon, the situation got better but not totally fine (the symptoms are a bit rarer now).

So I suspect that the fault is still on the power supply board. So can there be another component that is failing, or should I start to go through the solder joints and connectors, if there's a crack in a joint or bad connection with a connector?

Cheers,
Tuomas

[tuo]

So it seems that the problem is coming more constant now, after the last cap replacement normally turning the monitor off and back on again resolved the problem. It seems, that I'm taking this apart tomorrow again.

A couple of photos of the problems I have:

[PKTKS]

Hi,

(..)
So I suspect that the fault is still on the power supply board. So can there be another component that is failing, or should I start to go through the solder joints and connectors, if there's a crack in a joint or bad connection with a connector?

Cheers,
Tuomas

this is hard to spot.

Sometimes I poke around with a wood stick to check
cold LEAD FREE  crappy joints.

They sometimes look excessive dry with proper light under scope

Paul

[magic]

If you use analog VGA cable and random colors are disappearing that's usually failing cable or maybe VGA input on the monitor.

[tuo]

I tested both VGA and DVI-inputs and the problem was on them both.

Now I opened the monitor and reflowed the caps, that I have changed. And as I was putting it back again, I noticed that the cable from the control PCB to the panel was raised on one end of its connector. So of course I stucked it back again.

Everything works now, as they did after I last time opened the monitor and changed that big cap. Now if the situation stays the same for some days, then I think that it is now fixed.

[tuo]

I gave up on this monitor, as the problems were coming back again and again. I opened it couple of times more and these times the connections were fine, I tried reflowing some points that seemed not so good, but in the end the monitor worked for a while and started to fail again. So I decided, that it is too old for a total check to find the problem.