Re: I need help with my friend Sony GDM-FW900 24” CRT

The PSU output without heating the PCB
CN652
STB = 5V
80V = 79V
220V = 218V
12V = 12.0V
Heater = 5V

Moreover, when I turn the monitor on and off 5x times in a row each time, he has less red/green.
After 3 times, there is no red color anymore only green.
The picture is black after 2-5 sec -> green.
After 5 - 7, monitors turn on in the row picture stays black and has no color issue.

After that colors are normal permanently, this issue occurs only...

Re: I need help with my friend Sony GDM-FW900 24” CRT

Hello, there is an update, the monitor is now turning on. But it seems it's now harder for me to figure it out the main issue.

I have noticed that heating up IC620 powers on the monitor I think the 7 or 8 leg was responsible for that state. So I have replaced IC620 and the monitor is powering on every time but the screen is RED / GREEN.

I have noticed that shortly heating UP with a hairdryer back of PCB (not IC620) but closely around gives a proper picture for 2-4seconds (black background and this...

Re: I need help with my friend Sony GDM-FW900 24” CRT

I have replaced C646 (2.2uF 50V) now I have voltage on him

C646 = 28V, the weird part is the monitor woke up and gave a screen with an OSD picture. But the picture was very bright with a greenish picture on it. I turned him off and was able to turn him on one more time. Now, when I turned on the monitor no change, but the voltage on C646 is present. But when I put a multimeter on C647 to measure voltage the monitor powered on again (only a few times).

I have replaced C646 again and noticed, the...

Re: I need help with my friend Sony GDM-FW900 24” CRT

Hello again! I have performed some measurements around the G power supply and it has raised more questions.

G2 Voltage on A board = 0.00V
[G board (Power Supply)]
Measurements around IC610

C611 = 420V - (10) CATHODE but according to the Service manual it should be 376V

R643 = 0.0V
R629 = 0.0V
C639 = 9.3V
C648 = 14.8 V

R625 = 0.00V - should be 192V - (16) VG (H) (IC620 MCZ3001D SW REG CONTROL)

Those 2 resistors are...

Re: I need help with my friend Sony GDM-FW900 24” CRT

@stj perhaps you have an idea of what PS401 is responsible for? It is open for both sides. What type of electric circuit element it is?

^Also, no issues on the A board (with C block) and no cold joint on all boards. I have borrowed an ESR meter and checked all caps and they are fine (have not checked SMD ones). My desoldering kit is not a way for checking all caps blindly. I have no access to the scope as well.

Also, I have attached the video of the same monitor behaving the exact way as mine, but...

Hello, Badcaps is my last resort. I am the first owner of the monitor. I reached almost every repair store in my area, but no one even wanted to hear about troubleshooting an old CRT monitor. At this point, I have been trying to figure it out by myself, but I have no idea where to start or look for.

I wish to know how to think and locate a failing component. I will put all my efforts to learn and contribute.
[LIST=1][*]It started with a bright and greenish picture upon starting a cold monitor.[*]About 2 years ago, only on the cold boot, the screen started to occasionally flash...

Re: New Members - please post your introductions here

Hello!