Fixing a DAC-19M005 Power Supply - check my DX:

[alexanna]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

Since both or ours only reads about 100 ohms, does your unit work?
.

Remember this is a totally different board, I have borrowed some parts from the inverter section, But it will produce 5 volts to the connector at the logic board.
Al.

[kingofcoins]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

Rtech...OK now based on your experience, and the fact that so many of the OEM 40T03 fets blow, I'm going to go with the 60V 43A one...its also an IRF like yours...maybe your long success is because of the maker, no ?

Even 36A is some current rating, for a simple PSU/Inverter.I have used the IRF for the last three years, with no returns,AND these are used on other Boards as well.Its your choice of course,but 'the proof is in the eating'..as they say in some places in the world,and I have proved these are fine.Good Luck.

[kingofcoins]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

Al..yes I've that one bk'd too, been searching it, its a very long thread:
https://www.badcaps.net/forum/showth...hlight=l1975nw

On that F102, now that I've used another light I think we can agree its a resistor banded orange- black- orange- w/gold, value = 30k ohms. Since both or ours only reads about 100 ohms, does your unit work?

I will be ordering the 1/2w size from Digikey: P30KBBCT-ND....its like 14 cents.

[alexanna]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

You should search L2046NV.Its a Westinghouse monitor but it uses the same P/S
And there is some good information
Al

[Rtech]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

Even 36A is some current rating, for a simple PSU/Inverter.I have used the IRF for the last three years, with no returns,AND these are used on other Boards as well.Its your choice of course,but 'the proof is in the eating'..as they say in some places in the world,and I have proved these are fine.Good Luck.

[alexanna]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

Has 5 bands but the 5th band is black....so I'm guessing a fuse resistor...I think its orange, black, orange w/ gold....but it could be red, green, red ...either way its way more than 100 ohms.
What does yours measure ?

I have a good Delta DAC-12m033 board. It has the same gray component next to Q102 it is
Orange- black- orange-gold-black assuming my eyes are correct in the colors and its measuring 98.2 ohms.
Al.

[kingofcoins]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

Thanks but I think I may want to stay with the 30V 40A spec...I see the
IRF540 is rated at 100V 36A.
However Digikey has a 60V 43A version, is this a better choice than either the 30 V or the 100V ?
https://cdn.badcaps-static.com/pdfs/...0e3ce33550.pdf

Also I have corrected the F200 fuse choice to a Bourne 2 amp, cause that '5' is not what's on my fuse , its a capital 'S"...and S in Bourne=2amp
My Digikey choice is now:SF-0402S200-2CT-ND

For your 40T03GP, an IRF540 is an excellent alternative.

[Rtech]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

For your 40T03GP, an IRF540 is an excellent alternative.

[alexanna]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

Has 5 bands but the 5th band is black....so I'm guessing a fuse resistor...I think its orange, black, orange w/ gold....but it could be red, green, red ...either way its way more than 100 ohms.
What does yours measure ?

Well i am sorry but my reads open,
Al.
Did you have voltage to the large cap?

[kingofcoins]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

Has 5 bands but the 5th band is black....so I'm guessing a fuse resistor...I think its orange, black, orange w/ gold....but it could be red, green, red ...either way its way more than 100 ohms.
What does yours measure ?

I scraped some of the white glue away, the board is marked F102.The component is gray in color with some different colored bans on it.
I guess the board could be mismarked or could this be a fuse resistor?
Al.

[alexanna]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

Thanks Al, F102 looks like a resistor in my Ver 01A! It measures about 100 ohms...but I can't tell
the band colors, do you know the spec ?
Did you happen to have found a schematic of this board ?

I scraped some of the white glue away, the board is marked F102.The component is gray in color with some different colored bans on it.
I guess the board could be mismarked or could this be a fuse resistor?
Al.
no on the schematic

[kingofcoins]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

Thanks Al, F102 looks like a resistor in my Ver 01A! It measures about 100 ohms...but I can't tell
the band colors, do you know the spec ?
Did you happen to have found a schematic of this board ?

look right next to the center leg of Q102
Al

[alexanna]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

Al...
My sentiments exactly. The parts list my be overkill, but I'll have them to re-build as needed.
Also for that F102 fuse you asked about, would you please check my pics and point it out...can't seem to find it on my 19M005 board. Thank You !

look right next to the center leg of Q102
Al

[kingofcoins]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

Al...
My sentiments exactly. The parts list my be overkill, but I'll have them to re-build as needed.
Also for that F102 fuse you asked about, would you please check my pics and point it out...can't seem to find it on my 19M005 board. Thank You !

PlainBill,This monitor may be the exception to several failures ,What I have noticed is that failing capacitors cause a two second to black problem. The owner can get the monitor to work by pushing the power button multiple times and the monitor works until it goes to sleep,and the owner will repeat the power button process multiple times until it starts to work. Eventually the monitor quits altogether, and things get really fun to try to repair.
I agree with your systematic diagnostic process, Start with why there is no 164v to the large capacitor and build from there.
Al.

[kingofcoins]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

BILL:
Sorry for the confusion on parts and data sheets...this P/S was an old 'learning trial' I want to re-use. If you look closely at my attached pics, you should find several mistakes...one serious one on top and some goofs on bottom. As I recall not only was there one original failed component as you point out, but then as a newbie tester I made a few sparks, and blew my VOM fuse. That's why I pulled and tested so many parts now.
The 8 Leg SMPS controller is U 104, part DAP8A PWKJ.
Yes I found all the links to 40T03GP, but was at a loss to find such at my favorite Digikey (they don't carry AP's and I'm not a fan of FeeBay).

[alexanna]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

PlainBill,This monitor may be the exception to several failures ,What I have noticed is that failing capacitors cause a two second to black problem. The owner can get the monitor to work by pushing the power button multiple times and the monitor works until it goes to sleep,and the owner will repeat the power button process multiple times until it starts to work. Eventually the monitor quits altogether, and things get really fun to try to repair.
I agree with your systematic diagnostic process, Start with why there is no 164v to the large capacitor and build from there.
Al.

[PlainBill]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

equevarae...regarding the oem Mosfet, seems to be a no-name generic make and couldn't find any links anyway to 40t03GP.

Google brings up over 6000 hits. There are 26 auctions for them on eBay.

Retired...regarding the SMPS controller, since I've no schematic, so am I to look into part U102 a 4 pin chip labeled L0649 817B ?

The 817B is an optocoupler, not the SMPS controller. The SMPs controller is an 8 pin IC mounted on the bottom of the board near the SMPS transformer.

I note that you seem to be 'shotgunning' this (throwing a bunch of parts at it, hoping that one fixes the problem). While that is a way of fixing it, it's not an efficient way. One of the truths of electronics repair is that most failures are caused by a single component. Cascading failures are not impossible, but they are rare. And they follow a logical pattern.

Note the links in my signature. Pictures of the power supply board, top and bottom. Also, the part number of the SMPS controller.

PlainBill

[alexanna]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

One request, could you post photos of your board.
Some questions, when you checked the bridge rectifier did you remove it from the circuit?
There is another fuse you did not mention, it is F102 it is by the SMPS coil close to Q102.
Al.
F102 is coverd with white, I guess glue?

[kingofcoins]

Re: Fixing a DAC-19M005 Power Supply - check my DX:

equevarae...regarding the oem Mosfet, seems to be a no-name generic make and couldn't find any links anyway to 40t03GP.

Retired...regarding the SMPS controller, since I've no schematic, so am I to look into part U102 a 4 pin chip labeled L0649 817B ?

Why don't use the original one?

[kingofcoins]

Re: Data sheet links

Here's what I found on OEM and Digikey data sheets:
40T03GP Mosfet OEM sheet.... Can't find
DIGIKEY :
https://cdn.badcaps-static.com/pdfs/...8448f1f7d5.pdf

SBT 150 10 Shottky diode oem sheet (same make as Digikey) :

D2SB 60A Bridge rectifier oem Sheet is at: http://kazus.info/datasheets/102915/D2SB60A.html
DIGIKEY :


F200 fuse ...'S'on oem no schematic available, size 0.126" L x 0.063"
DIGIKEY SHEET:https://cdn.badcaps-static.com/pdfs/...29bd6ba8e7.pdf