245BW, can't find problem. No 24 or 6.3V, standby is good.

[epicelite]

Power light comes on but I'm getting nothing on the 24v or 6.3v outputs from the power supply.

The only lead I have is the large cap "CP801" which says "450WV 82Uf" on it but only gives out 173V's. Someone told me this is normal but I'm not sure if I should trust them.

Model # on the board is: BN44-00195A

[PlainBill]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

Power light comes on but I'm getting nothing on the 24v or 6.3v outputs from the power supply.

The only lead I have is the large cap "CP801" which says "450WV 82Uf" on it but only gives out 173V's. Someone told me this is normal but I'm not sure if I should trust them.

Model # on the board is: BN44-00195A

There are several other threads on this monitor / power supply. This sounds like a common problem - something about three resistors that often fail.

PlainBill

[jetadm123]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

The 3 resistor failure problem only applies to the BN44-00173A model power supply. Your model supply is different (BN44-00195A). Please post some good focused photos of the top and bottom of the entire power supply per PlainBill's links.

[epicelite]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.





All the regular cap's have been replaced, I checked all the resistors for continuity, fuses are good.

[PlainBill]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

All the regular cap's have been replaced, I checked all the resistors for continuity, fuses are good.

In the future, please attach the photos using 'Manage Attachments' - below the text entry area. If additional pictures become necessary, it is best if they are as close to 2000 x 2000 pixels as possible (without going over). Here's why:

1. On the top view I see a cap that looks suspiciously like it is bulging. I think I can see the identifier, but can't read it. The best I can do is say it is directly above the 'A' in BN44-0195A.

2. Above that cap is an 8 pin IC. Again, while I can see the identifier, but can't read it. That is the SMPS controller. What is the part number?

3. To the right of the board number are a pair of connectors. I can see labels indicating the function of the pins, but again, they are unreadable. One of the pins may be labeled 5V Stby, or something like that. What is the voltage on that pin?

PlainBill

[epicelite]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

In the future, please attach the photos using 'Manage Attachments' - below the text entry area. If additional pictures become necessary, it is best if they are as close to 2000 x 2000 pixels as possible (without going over). Here's why:

1. On the top view I see a cap that looks suspiciously like it is bulging. I think I can see the identifier, but can't read it. The best I can do is say it is directly above the 'A' in BN44-0195A.

2. Above that cap is an 8 pin IC. Again, while I can see the identifier, but can't read it. That is the SMPS controller. What is the part number?

3. To the right of the board number are a pair of connectors. I can see labels indicating the function of the pins, but again, they are unreadable. One of the pins may be labeled 5V Stby, or something like that. What is the voltage on that pin?

PlainBill

Well if I had a better camera maybe...

1: Cap is just fine, and it's new.

2:
A6159
SK812
419K

3: Mistake in the thread title, 6.3V should be 5.4V. There is nothing coming out of it.

(I don't see a attack image option when posting?)

[alexanna]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

^ Good lighting and a very steady hand works wonders.
Go advanced on your Post,and you will see the option.
Maximum dimensions allowed are 2000x2000 pixels so you will have to resize the pictures.

[epicelite]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

Well that's as good as my camera can do so if you can't make it out in those pics I dunno what to tell ya'.

[PlainBill]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

Well that's as good as my camera can do so if you can't make it out in those pics I dunno what to tell ya'.

You can do what you have done, it just means the information transfer is a bit slower. The sketch gives me the information I needed, your note adds more, and the IC is an Allegro MicroSystems STR-A6159. It's an combination SMPS controller and power FET in one package. The datasheet of that IC is here.

From the datasheet, pin 3 is Ground, pin 2 is Vcc. With power on, CAREFULLY measure the voltage from pin 3 to pins 1, 2, 4, and 5. Do NOT measure the voltage on pins 7 or 8; if the IC is working it could destroy your DMM.

Oops, almost forgot. In the picture, the pins are numbered counterclockwise, starting at the lower left.

PlainBill

[epicelite]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

Oh well this sounds dangerous... SIGN ME UP!

1:0.01
2:11.6
4:0.01
5:153.2

[PlainBill]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

Oh well this sounds dangerous... SIGN ME UP!

1:0.01
2:11.6
4:0.01
5:153.2

Pin 2 is the key. The SMPS controller won't start until it reaches 17.5 volts. On similar ICs, the solution has been to replace the SMPS controller. You might wish to first check the capacitor connected to pin 2.

PlainBill

[epicelite]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

Well where the heck do I get a new one?

EDIT: Measured what I think is the correct cap with it powered on and it was giving out 0.01V's. Could you circle the cap that I should be measuring in the picture?

[PlainBill]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

Well where the heck do I get a new one?

EDIT: Measured what I think is the correct cap with it powered on and it was giving out 0.01V's. Could you circle the cap that I should be measuring in the picture?

Available from this firm. I'm not familiar with the firm,and the price seems somewhat high. I found it by Googleing buy STR-A6159.

The picture of the bottom wasn't good enough to allow me to positively identify the startup cap. The cap circled in blue is the primary suspect. The ones circled in yellow are also possibilities.

Plainbill

[Toasty]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

B&D is fine. Used them for TV parts in the past.

Everybody else has the part cheaper, but no stock...

Newark has them for 92¢ each if you buy 1000

If you replaced all the caps in that area as you said, what brand and series did you use?
i.e.- Radio Shack caps are not acceptable.

Trace the power supply circuit to that chips input (Pin 2) as PlainBill noted.

A closer, better lit picture of the back of the board (mind the glare) of the upper left which is the area of interest. Essentially (from your current photo) above the horizontal black line and the left of the vertical black line/slots.

.

[epicelite]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

Sorry I didn't want to upload it here because I would have to make it smaller. Ignore what looks like a really bad solder job I fixed it and it looks a lot better in person. I wasn't the one that replaced the caps.

[Toasty]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

It would have been fine. Edit your post, pick "Go Advanced" and choose "Upload Attachment" and use the "Upload from URL" of the picture from Google. Quick!

TOOO late. I did it for you.

[epicelite]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

I tried it just says upload failed because its too big I think. Why does it matter where it's hosted anyway?

[Toasty]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

The -file- size is the limit. Your pic is only 140kb. The forum limit is 1.9Mb for .jpeg and 3.8Mb for .jpg (there's a difference?).

The pixel size limit is requested to be no greater than 2000 x 2000 pixels. The forum auto-resizes it when you post it inline so it doesn't FUBAR all the pages. Posting it as an attachment doesn't screw with people who have limited bandwidth and speed. It allows them to -choose- to see the big pictures, one at a time, not have the forum "shove them all down their throats".

Posting it on the site preserves it for eternity (LOL!) in our server. ImageShack and the like sometimes delete the pics or the account and then it's lost to anyone looking for info here in the future.

It may have failed because edit time expired (30 minutes, IIRC).

[epicelite]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

That cap circled in blue, it MIGHT be bad? I can't get more then 0.07V's from it. It also has some clear goo on the top that I thought was just hot glue but maybe I am wrong?

EDIT: You know what, I'm an idiot. The more I think about it I realize that can't be hot glue. I will go down to radio shack tomorrow and see if they have anything.

I can go higher in the uf rating right?

EDIT 2: Screw it I will just order from Digikey, I need a DVI cable too and don't wanna pay $30 for one.

[epicelite]

Re: 245BW, can't find problem. No 24 or 6.3V, standby is good.

Nope it still doesn't work, I refuse to pay $10 for a single IC. >:|

Especially when it's not guaranteed to be the problem.