Chimei CMV 221D - doesn't power on

[funkster]

Hi, a few weeks back I found my Chimei 221D LCD Monitor not able to power up in the morning after I left it in standby mode with my computer on. The power light doesn't light up at all when pressing the power button to turn the screen on.

I took the initiative to open it up and have a look for blown fuses, they all checked out with my multimeter. I also noticed that the Capacitors where hissing. The power board is a DAC-19M009, and the main board is a a170e2-e03-h-s6

I tried to test the voltages going to the a170e2-e03-h-s6 main board and they seemed okay, but then I accidentally shorted out 2 of the voltages and blew the 4 amp "W" F102 fuse nearby. So I went and bought a replacement kit for the DAC-19M009 board off ebay, it came with the 4amp "W" Fuse, replacement capacitors except for the big 120uf 400V, and replacements for the AOP605 MOSFETs.

I waited about 3 weeks to revieve them, then took out my trusy old soldering iron and went ahead and replaced the capacitors, 4 amp fuse, and MOSFETs. I went ahead and plugged the power in and still it work power up

The only thing I managed to fix was the hissing from the old capacitors

Can anyone be of any help? Is it possible to use a "a170e2-e03-h-s6" main board from a different brand? because I have searched for it and have found people sell them, but they had no chimei version. If I did replace that wouldn't it just change the what it is detected as, and also change the menu etc?

[jetadm123]

Re: Chimei CMV 221D - doesn't power on

1) What were you checking when you shorted out the supply? You may have shorted one or more of the semiconductors.

2) Did you go back and verify that you installed the caps correctly?

3) I believe the Delta power supplies have several SMD fuses underneath the board. Check around and look.

4) Post a photo of the bottom of the power board.

5) Do you get any activity from the power light?

[retiredcaps]

Re: Chimei CMV 221D - doesn't power on

I went ahead and plugged the power in and still it work power up

If you see the power LED come on, then most likely you have some or all of the secondary voltages (5V DC and 19V DC).

If the power LED does not come on, then check carefully check (high voltage alert) the main filter capacitor (the big one) for mains x 1.414 DC voltage.

That is, if you live in the USA, 120V x 1.414 = 160 to 165V DC.

[Toasty]

Re: Chimei CMV 221D - doesn't power on

The little cap next to the blue cap near the transformer. Start up cap.

IIRC 22uF @ 50v. Panny FM or FC.

Toast

[funkster]

Re: Chimei CMV 221D - doesn't power on

1) What were you checking when you shorted out the supply? You may have shorted one or more of the semiconductors.

2) Did you go back and verify that you installed the caps correctly?

3) I believe the Delta power supplies have several SMD fuses underneath the board. Check around and look.

4) Post a photo of the bottom of the power board.

5) Do you get any activity from the power light?

Firstly thank you to all who have tried to help. I will try and answer all the questions, and recommendations you gave have given me. Here are my responses.

1) I'm not sure, but there are two voltages going to the other main board, Two +5V pins, and a +13.8V pin. I may have shorted them out togther or one of them to another pin beside it. I had replaced the F102 fuse which was underneath the board and have reverified that it's okay and the voltages are reading good.

2) Yes.

3) Once again I can only seem to find the F102 fuse. The other fuses F100, F101 and F200 that are on the top of the board are also okay.

4) Check.

5) No Power LED activity.

[funkster]

Re: Chimei CMV 221D - doesn't power on

If you see the power LED come on, then most likely you have some or all of the secondary voltages (5V DC and 19V DC).

19 Volts? I can only find 13.8 volts

If the power LED does not come on, then check carefully check (high voltage alert) the main filter capacitor (the big one) for mains x 1.414 DC voltage.

I can verify that it is reading correctly for 250Vx1.414

[funkster]

Re: Chimei CMV 221D - doesn't power on

The little cap next to the blue cap near the transformer. Start up cap.
IIRC 22uF @ 50v. Panny FM or FC.

I tried replacing that just a few moments ago, but alas it did not fix it.

[alexanna]

Re: Chimei CMV 221D - doesn't power on

When you say no activity from the front power light, does that mean not even an amber stand by light?
Al.

[funkster]

Re: Chimei CMV 221D - doesn't power on

When you say no activity from the front power light, does that mean not even an amber stand by light?
Al.

Yes. The front LED doesn't even light up to show a standby orange light either. Hmm, one thing I should check is if the led is actually receiving power at all. I can't do it right now as I have to go to sleep.

edit:
Although it doesn't turn on with the power button. The screen that is.

[PlainBill]

Re: Chimei CMV 221D - doesn't power on

It very well could be a bad logic card. Before replacing it, here are some points to check.

F1 (left side near the connector to the power supply) Check the resistance.

U6 (upper left corner) What is the part number? Check the voltage on the three legs (the tab is connected to the middle pin). Use the mounting screw near the top center as ground.

U7 (middle of board) Same steps as U6, but voltage may be different.

PlainBill

[Toasty]

Re: Chimei CMV 221D - doesn't power on

Are you applying a video source to the VGA input? I've seen these not respond without it.

You must have the 5v and 12v from the power supply. If the main switcher is running, you should have both voltages.

What cap brand/series did you use to replace the little one I suggested before? For some reason it is -very- picky about that cap. That's why I suggested FC or FM. I had a nearly identical unit with a new Rubycon YXG there and it would not run. Replaced with an FM and it took off right away. It was a 22uF @ 50v, correct?

Toast

[jetadm123]

Re: Chimei CMV 221D - doesn't power on

Can you provide the part number of the device circled in yellow?

[funkster]

Re: Chimei CMV 221D - doesn't power on

It very well could be a bad logic card. Before replacing it, here are some points to check.

F1 (left side near the connector to the power supply) Check the resistance.

U6 (upper left corner) What is the part number? Check the voltage on the three legs (the tab is connected to the middle pin). Use the mounting screw near the top center as ground.

U7 (middle of board) Same steps as U6, but voltage may be different.

PlainBill

F1, U6, U7

I can't seem to find these labels anywhere?

[funkster]

Re: Chimei CMV 221D - doesn't power on

Can you provide the part number of the device circled in yellow?

Yes, from the top an down, "TIP122FP" "CCODL VW" "MAR 631" and then 2 logos "ST" & "e3" with a circle around it.

[jetadm123]

Re: Chimei CMV 221D - doesn't power on

F1, U6, U7

I can't seem to find these labels anywhere?

Located on the logic card

[funkster]

Re: Chimei CMV 221D - doesn't power on

Are you applying a video source to the VGA input? I've seen these not respond without it.

I haven't tried the vga input, but I have tried the DVI input. When I plug it in the computer makes that detection sound, so it seems to pick it up.

You must have the 5v and 12v from the power supply. If the main switcher is running, you should have both voltages

Well, I get +5V, and +13.8V pins going to the logic board as indicated on the power board. Main switcher? What is that?

What cap brand/series did you use to replace the little one I suggested before? For some reason it is -very- picky about that cap. That's why I suggested FC or FM. I had a nearly identical unit with a new Rubycon YXG there and it would not run. Replaced with an FM and it took off right away. It was a 22uF @ 50v, correct?
Toast

Hrmm, I guess I need to buy a proper capacitor then, as I used 2 x 10uF 50V capacitors in parallel, not sure what brand they are though as they where spare parts from something else.

[Toasty]

Re: Chimei CMV 221D - doesn't power on

See circled items in attached photo.

[funkster]

Re: Chimei CMV 221D - doesn't power on

F1 (left side near the connector to the power supply) Check the resistance.

U6 (upper left corner) What is the part number? Check the voltage on the three legs (the tab is connected to the middle pin). Use the mounting screw near the top center as ground.

U7 (middle of board) Same steps as U6, but voltage may be different.

Okay after realising that I was looking at the wrong board lol

F1 checks out as a short, so that must be okay.

U6 Part no. is "AMC1117" "-3.3 F0628J" The voltages from left to right pins are 0V, 3.27V, 4.99V.

U7 Part no. is the same as U6, voltage readings from left to right pins are 0V, 2.41V, 4.77V.

[PlainBill]

Re: Chimei CMV 221D - doesn't power on

Okay after realising that I was looking at the wrong board lol

F1 checks out as a short, so that must be okay.

U6 Part no. is "AMC1117" "-3.3 F0628J" The voltages from left to right pins are 0V, 3.27V, 4.99V.

U7 Part no. is the same as U6, voltage readings from left to right pins are 0V, 2.41V, 4.77V.

Bingo!!! That's a winner. CAUTIOUSLY check it's temperature. It's output (the center pin) should be 3.3V. Either it's overloaded, or it's defective.

PlainBill

[funkster]

Re: Chimei CMV 221D - doesn't power on

Bingo!!! That's a winner. CAUTIOUSLY check it's temperature. It's output (the center pin) should be 3.3V. Either it's overloaded, or it's defective.

Is that some kind of regulator chip? If it wasn't defective would it still output 3.3V even though its getting 4.77V?

edit: I don't have any kind of thermometer to measure its temp, although while I ground myself and touch both U6 & U7 to compare, U7 seems ever so slightly warmer.

edit2: If I was to replace it with an equivalent from on of these: http://shop.ebay.com.au/i.html?LH_Av...1&_sop=2&_sc=1

Is it likeley that it could be fixed? Or is it likely that other components are fried in that circuit as well?