Sony GDM-F500R (G1 Chassis) has trouble turning on

I got this monitor used five years ago. Since then it has always had the overbrightness problem, but I scraped by with brightness set to 0 and contrast to 100. This was annonying, and the local service center in India refused to service it. About a year back, it started exhibiting a new problem -- it will not turn at all! The power LED will turn on, but will flash in amber every 1.25 seconds. Turning it on and off did nothing. So I put the monitor in cold storage. After about a couple of months, curiosity got the better of me, and when I plugged it in, it worked just fine. It worked for some more months, and then mysteriously, refused to turn on one fine day. All I got is that blinking amber light. In frustration/desperation, I pushed the power button for about fifteen minutes, and it turned on. Everyday since then, regardless of whether it was in standby mode or turned off overnight, my daily morning ritual is to repeatedly push the power button in order to turn my monitor on. Sometimes it takes a few minutes, sometimes over couple of hours. After some googling, I was able to download the schematic for it and also got information on using WinDAS to adjust its G2 register to correct the brightness problem. I build the necessary serial cable and now the monitor is close to perfect (displaywise: G2 was set to 199, I lowered it to 155), except for the power-on problem.

Here is some detailed information on how I get to turn my monitor on: With 220V supply:

  1. Turn the monitor on. If amber light flashes, go to #2, else it turns on.
  2. Turn it off. Wait for 5 sec (exact)
  3. Repeat from 1.

With 110V Supply:

  1. Turn the monitor on. If amber light flashes, go to #2, else it turns on.
  2. Turn it off. Wait for less than 1 sec.
  3. Repeat from 1.

The interesting thing to note here is that when the monitor does eventually turn on, it is preceded by the sounds of relay clicks. Once the relays start clicking, it will not turn on right away, but after a few more on-off cycles, it will. The moment I hear the first relay click, I am relieved since I know the monitor will eventually turn on. But I think the problem is getting worse, since my daily wait time is getting longer.

I suspect some electrolytic capacitor has gone bad, but don't have an ESR meter. I am going to build an ESR meter and go over all the electrolytic capacitors inside.

Does anyone have better clue than me, or is it a well known problem?

Thanks.

Reply to
redblue
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I have made additional observations. The constant on-off cycles are not necessary. What I did was turn the screen saver off, so that the computer generated a signal continuously. Now all I have to do is turn the machine/monitor on and wait for about 20-30 minutes. The monitor turns on eventually. I guess the problem really is that the monitor takes a long time to turn on after more than an hour of rest.

Reply to
redblue

I have made additional observations. The constant on-off cycles are not necessary. What I did was turn the screen saver off, so that the computer generated a signal continuously. Now all I have to do is turn the machine/monitor on and wait for about 20-30 minutes. The monitor turns on eventually. I guess the problem really is that the monitor takes a long time to turn on after more than an hour of rest.

Reply to
redblue

Fixed it. Turns out that the problem was bad capacitors afters all. Five of them in the power supply. 100uF and 47uF variety. I think there were two more that were borderline cases, but I left them in for now. From the looks of it, and how they were all clustered, I think the 5V regulator section must have kept them hot over the years, specially since standby needs this part of the circuitry live all the time. $0.18 repair saves a $1,800 monitor.

Reply to
redblue

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