CHIMEI CMV 221D won't power up when cold.

[torin3]

Ok, I was swapping out video cards on my computer last night. I've been leaving my monitor on with the power setting to never shut the monitor off. This is because about 6 months ago I noticed it was very hard to turn the monitor on after it had powered down when idle. I would have to press the power switch several times, and the light would flicker on for a second or so and then shut off again. So, I figured it was hard to turn off, I would make sure to leave it on as much as possible.

Well tonight, I couldn't get it to turn back on. When pressing the switch, the green power LED would flicker on for about a half of a second, then shut off. I first was suspicious of the switch but when I popped open the back (don't worry it's not worth it to me RMA it) the switch didn't appear to have any problems. However, it looks like I have several bad caps in it.

Given its behavior of being harder to turn on the longer it had been left off, and that it has bad caps in it, does it seem reasonable that replacement caps might fix it?

Here is what it looks like:





My soldering skills are decent, but a bit basic.

[Bobdee]

Re: CHIMEI CMV 221D won't power up when cold.

It has to be recapped no matter what
That should put it right no doubt, If not post back plenty of good help
If you post the Brand of cap + voltage + uf + Series, (found on caps)
Someone will advise on suitable replacements

[PlainBill]

Re: CHIMEI CMV 221D won't power up when cold.

I agree with Bobdee. You've got at least 5 bad caps there, and another 4 that should be replaced due to guilt by association. Replace every electrolytic in the power supply / inverter EXCEPT the big 450 Volt, 100 uF one.

PlainBill

[torin3]

Re: CHIMEI CMV 221D won't power up when cold.

I agree with Bobdee. You've got at least 5 bad caps there, and another 4 that should be replaced due to guilt by association. Replace every electrolytic in the power supply / inverter EXCEPT the big 450 Volt, 100 uF one.

PlainBill

I was planning on replacing all of them, as long as I've got the iron out. I'll leave the big one alone. I can't read the ratings on several of them due to glue, but one I've got them out, I'll post them here.

I originally asked about this on OCForums, and along with pointing me here, they suggested Panasonic FC caps as the replacements.

It was also pointed out that another part of the board has some evidence of extra heat, and that I should resolder those connections.

[PlainBill]

Re: CHIMEI CMV 221D won't power up when cold.

I was planning on replacing all of them, as long as I've got the iron out. I'll leave the big one alone. I can't read the ratings on several of them due to glue, but one I've got them out, I'll post them here.

I originally asked about this on OCForums, and along with pointing me here, they suggested Panasonic FC caps as the replacements.

It was also pointed out that another part of the board has some evidence of extra heat, and that I should resolder those connections.

I prefer Panasonic FM and FC in that order, chiefly because the FMs often have better specs at lower cost. Nichicon and Rubycon also have excellent low ESR caps.

The 'toasted' section of the board is due to the drivers for the transformers in the inverter section. That discoloration is common. Resoldering the transformers is always a good idea.

PlainBill

[torin3]

Re: CHIMEI CMV 221D won't power up when cold.

Turns out with a little creative lighting, I was able to read all the caps. This board has:

1 x 22uF - 50V Brown
3 x 220uF - 25V Black
1 x 330uF - 25V Green
1 x 1000uF - 10V Green
2 x 1000uF - 25V Black
1 x 2200uF - 10V Black

I'll post the physical dimensions once I've got them out of the board.

[torin3]

Re: CHIMEI CMV 221D won't power up when cold.

Okay, here are the dimensions (L x W x wire spacing)

1 x 22uF - 50V Brown 5mm x 12mm x 2mm
3 x 220uF - 25V Black 8mm x 12.5mm x 3.5mm
1 x 330uF - 25V Green 8mm x 14.75mm x 3.5mm
1 x 1000uF - 10V Green 10mm x 16.5mm x 5mm
2 x 1000uF - 25V Black 10mm x 21mm x 5mm
1 x 2200uF - 10V Black 13mm x 20mm x 5mm

For the replacement ones, I got some of the physical sizes wrong (because I ordered them before I removed the old ones and measured them). But they should be close enough.

For the 330uF one I ordered a 10mm x 12.5mm x 5mm.
For the 1000uF 10V one I ordered a 8mm x 20mm x 3.5mm

Should be close enough though.

[torin3]

Re: CHIMEI CMV 221D won't power up when cold.

Well, the caps arrived this morning. I'm lucky I decided to check the mail when I did. There was already a notice to go an pick them up at the post office on Monday. However, the carrier was across the street right then, so I was still able to get them.

It went a little easier than I expected. I haven't plugged it in yet, because I want to trim the wires a little closer to the board before I put it in, and I haven't gone out to the shop yet to grab the right tool for it.

Anyway, here are before and after photos:

[torin3]

Re: CHIMEI CMV 221D won't power up when cold.

Aaannnd....

It works!

Thanks everybody!

[torin3]

Re: CHIMEI CMV 221D won't power up when cold.

Forgot to mention, the bad caps were CapXon brand.

[pantherts]

Re: CHIMEI CMV 221D won't power up when cold.

Great job Torin! I just did this same exact repair myself! There's a thread floating around here somewhere about it. Enjoy your new(ish) recapped monitor! I know i'm enjoying mine!