Chimei DAC-19M009 Power Supply problems

[cds1984]

Re: Chimei DAC-19M009 Power Supply problems

Thanks for the fast response... and I do mean fast!

[PlainBill]

Re: Chimei DAC-19M009 Power Supply problems

Thanks for the fast response... and I do mean fast!

De Nada.

PlainBill

[ntehicks]

Re: Chimei DAC-19M009 Power Supply problems

Chimei DAC-19M009 Power Supply problems
I have the same problem with my power supply. I have tested and the fuse right under the power is blown. I have also tested the bridge rectifier it is bad. I have replaced both and still the fuse blows. I have tested the P10NK60ZFP and it tests good. my question is does anyone know what the transformer should test? the label on the pcb is LF100

[cnservices]

Re: Chimei DAC-19M009 Power Supply problems

I've recently acquired the VX2235WM monitor with the DAC-19M009. My issue is no power, no LED light. I've read through this thread and tried mostly everything in my ability. I have done electronics years ago in the Navy, but a little rusty on the soldering. Here's what I've done so far:

Visual Inspection - no leaking/bulging caps, no noticeable solder issues
Tested F200 and and F101 fuses -good
Tested the big cap (400V 120uF) - good
MOSFETS tested good
Removed the startup cap and tested - good
Bridge Rectifier tested good
Tested the pins connecting to the logic board, no 5V to be found.....

Not sure where to look next. Please bear in mind I'm waaaay out of practice with this, so you may get a response of "huh" or "how do I do that"

Thanks for any help you can offer

[Rtech]

Re: Chimei DAC-19M009 Power Supply problems

Measuring the Voltage across the large cap is the first thing to check, and should be about 1.4 times the AC input voltage,,although the measurement will be DC volts.If that is fine, then on the bottom of the board is an 8 pin SMPS chip...find the Datasheet,and check what voltages you have particularly the Vcc pin.

[RethoricalCheese]

Re: Chimei DAC-19M009 Power Supply problems

Having a problem with the same board or maybe even with the other board.
It had bad caps so I changed them. Got the monitor working. A week later it did not work anymore. When plugged in, there is a clicking sound and 2 LED lights in front are blinking (I could barely see it) in the same tact as the clicking sound.

There is no clicking sound when the other board is not connected.

I tested out large cap - OK, rectifier - OK, SMPS has 11.7V - OK (according to datasheet), 13.8V - OK, 5v - OK. Removed F200 - still same problem.
All caps have been replaced.

Taking in mind this information, is the problem hidden in power supply board or logic board/controller or whatever you call that.

[selldoor]

Re: Chimei DAC-19M009 Power Supply problems

Boss - what monitor/model is it on - the bulbs and wiring on some chimei monitors tend to burn up.

[RethoricalCheese]

Re: Chimei DAC-19M009 Power Supply problems

While I tested, I had no LCD panel even connected. Only the power supply board, controllerboard and buttonboard. Nothing else.

The model in question is VX2235wm

[selldoor]

Re: Chimei DAC-19M009 Power Supply problems

Without bulbs connected the powersupply/inverter will go into protection and never start.

[RethoricalCheese]

Re: Chimei DAC-19M009 Power Supply problems

Yes, I am aware of that but it has nothing to do with the problem at the moment. The problem is that there is a certain clicking sound and it does not start up (with or without CCFL-s connected, it doesn´t really matter)

[selldoor]

Re: Chimei DAC-19M009 Power Supply problems

Hmm, so are you sure the ccfls are good? if one is bad again the protection would kick in.
What make/series of caps did you use as replacements, and did you replace the 22uf50v startup cap - what voltage do you get across it?

[RethoricalCheese]

Re: Chimei DAC-19M009 Power Supply problems

I am not 100% sure but I will worry about that later. I am 100% sure that one of the boards is faulty.

As a replacement I used leaguer and jamicon caps, which have been working before too (I have fixed 100-200 LCD-s using these caps)

I replaced 22uF 50V cap with 33uF 50V cap and the problem persisted.
Voltage across that cap is 12.5V

When I removed 5V rail fuse for testing, there was no clicking sound anymore while I had controllerboard connected. Just letting you know, maybe it helps with something.

[selldoor]

Re: Chimei DAC-19M009 Power Supply problems

Ok - did you try jump starting - Can you find a pin labelled pson or blon or on/off on the main board connector. with the main board disconnected but with the lamps plugged in,
get a 500ohm resistor and jump the 5v pin to the pson or blon pin Switch on the mains power and see if the lamps come on ( may also need a resistor jumper to Blon.)

[RethoricalCheese]

Re: Chimei DAC-19M009 Power Supply problems

Just tried jump starting. The lights turn on for half a second and go back off.

The lamps I used are taken from another monitor and are in 100% working condition.

[Amraks]

Re: Chimei DAC-19M009 Power Supply problems

this was what mine was doing.

Haven't fixed it as I am stuck with getting that cap 220uf 50v cap the trace was lifted. having trouble finding where its meant to go on the negative side.

pretty sure positive lead traces to above zener diode.

[selldoor]

Re: Chimei DAC-19M009 Power Supply problems

The Boss
Ok - how about testing the inverter transformers - see here
https://www.badcaps.net/forum/showpo...68&postcount=6

Is your board the same ( I am not certain those are the secondaries but try there first.

[selldoor]

Re: Chimei DAC-19M009 Power Supply problems

The Boss
As you see Amraks has a problem -If your board is the same any chance you could take a detailed picture of the yellow box area in the picture in this post
https://www.badcaps.net/forum/showpo...0&postcount=39

[RethoricalCheese]

Re: Chimei DAC-19M009 Power Supply problems

this was what mine was doing.

Haven't fixed it as I am stuck with getting that cap 220uf 50v cap the trace was lifted. having trouble finding where its meant to go on the negative side.

pretty sure positive lead traces to above zener diode.

I am not sure if the picture helps so I tested it instead.

Positive side is connected with D109 and R133, negative side is connected with C121 and R144.

Positive side rail should go underneath a diode also.

[RethoricalCheese]

Re: Chimei DAC-19M009 Power Supply problems

The Boss
Ok - how about testing the inverter transformers - see here
https://www.badcaps.net/forum/showpo...68&postcount=6

Is your board the same ( I am not certain those are the secondaries but try there first.

Transformer pins marked S2 and S4 in your picture are not connected with anything

725 ohm between S1 and S3 if that might be important to know.

[selldoor]

Re: Chimei DAC-19M009 Power Supply problems

Each transformer has two pins which should read ( probably as you say around 725 ohms) I just guessed which pins and was wrong.
To find out you need to number the pins in your head then test 1 to2 1 to 3 1 to4 1 to 5
and so on then 2 to3 2 to4 2 to 5 :: 3 to 4 3 to 5 3 to6 and so on until you find which are the secondary pins on one transformer then just check those pins on the other.

As one of the pins I marked that measures 725 ohms use that as pin 1 and test it against other pins on the same transformer and let us know.