How to disassemble Viewsonic VX924
- Thread starter wo1n
- Start date
We have some monitor repair guides posted on our site that include dis-assembly instructions. Check them out at : www.ccl-la.com/badcaps.htm
The most common problem with LCD monitors are bad capacitors on the power supply/inverter board. You should be able to do the repair yourself. Check our site and look at the pictures of what to look for. Now open the back of your monitor and look for the bad parts, replace any you find that look like the pictures. Be sure to use high temp replacements rated at 105c not like ones you get from Radio Shack. The values you will need are going to be printed on the sides of the bad ones you take out. Remember to insert the new caps with the polarity stripe on the side going the same direction as the old ones that came out. If you have questions about repairing your monitor email me and I will be glad to assist.
Buddy
Corporate Computer
www.ccl-la.com
tech@ccl-la.com
The most common problem with LCD monitors are bad capacitors on the power supply/inverter board. You should be able to do the repair yourself. Check our site and look at the pictures of what to look for. Now open the back of your monitor and look for the bad parts, replace any you find that look like the pictures. Be sure to use high temp replacements rated at 105c not like ones you get from Radio Shack. The values you will need are going to be printed on the sides of the bad ones you take out. Remember to insert the new caps with the polarity stripe on the side going the same direction as the old ones that came out. If you have questions about repairing your monitor email me and I will be glad to assist.
Buddy
Corporate Computer
www.ccl-la.com
tech@ccl-la.com
I figured out how to pop the the two plastic halves apart. I used a popsicle stick forced into the groove and then just ran it all around the perimeter of the case. It came right apart and I didn't break any of the damn plastic latches.
Sure enough a visual inspection of the power supply showed two 470uF caps bulging about 125% of there normal size. I had some higher voltage rate 470uF's on hand, swapped them in but still no go. The voltage rail measured a steady 12V at the caps.
I further disassembled the entire screen frame to get at the CFCL's figuring they might be dead. I noted that the tubes connected to one output were flashing at power up while the 2nd set were not. I swapped the tubes around and noted that the one previously flashing now was not and visa versa.
So I figured there was a problem with the CFCL startup/voltage circuits. I quickly found the pair of npn transistors that drive the transformer on the side not flashing were shorted. I'd venture a guess the mosfet driving the coil is probably toast too.
I found an app note for the CFCL circuit, though I could not find the actual chip spec on the web. Damn Far East crap. But, I figured this was all repairable on the power supply so I started to reassemble the entire frame. It was at that point when I reached across my work bench to pick up the actual LCD panel with the thousand flat ribbon cable connections across the top and I accidently "unzipped" one entire section. DOH.
This puppy is landfill.
Thanks for the response,
WO1N
PS: I can spare out the good CFCLs, the video subsection or even the defective power supply if anyone wants to pick up the shipping.
Sure enough a visual inspection of the power supply showed two 470uF caps bulging about 125% of there normal size. I had some higher voltage rate 470uF's on hand, swapped them in but still no go. The voltage rail measured a steady 12V at the caps.
I further disassembled the entire screen frame to get at the CFCL's figuring they might be dead. I noted that the tubes connected to one output were flashing at power up while the 2nd set were not. I swapped the tubes around and noted that the one previously flashing now was not and visa versa.
So I figured there was a problem with the CFCL startup/voltage circuits. I quickly found the pair of npn transistors that drive the transformer on the side not flashing were shorted. I'd venture a guess the mosfet driving the coil is probably toast too.
I found an app note for the CFCL circuit, though I could not find the actual chip spec on the web. Damn Far East crap. But, I figured this was all repairable on the power supply so I started to reassemble the entire frame. It was at that point when I reached across my work bench to pick up the actual LCD panel with the thousand flat ribbon cable connections across the top and I accidently "unzipped" one entire section. DOH.
This puppy is landfill.
Thanks for the response,
WO1N
PS: I can spare out the good CFCLs, the video subsection or even the defective power supply if anyone wants to pick up the shipping.
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