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

[epicelite]

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

Apologies that it took me so long to get around to doing this, but here ya' go!

Meter on the 20V DC setting.

1. 5.5
2. 0.01
3. 2.7
4. N/A
5. 5.7
6. 0.01
7. 0.01
8. 5.5
9. 5.3
10. 16.0
11. 14.4
12. 0.01
13. 0.01
14. 0.01
15. 0.01
16. 0.01
17. 0.01
18. 15.4

[PlainBill]

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

Apologies that it took me so long to get around to doing this, but here ya' go!

Meter on the 20V DC setting.

Well, that didn't work out very well. In another thread zulururu has the results and readings from the same pins. Here they are and what the pin does.
1: 5.05v Oscillator charge
2: 5.05v Oscillator return
3: 2.54v Oscillator control current
5: 5.08v 5.1 V reference
6: 0.07v Error amp out
7: 0.07v Error amp - in
8: 5.04v Error amp + in
9: 14.60v Enable adj.
10: 0v Fault input
11: 0.19v Soft start
12: 14.06v B output
13: 0v Gnd
14: 0.27v A Output
15: 15.06v Vcc
16: 5.04v One shot RC

One obvious problem is somehow you came up with an extra 2 pins. What is worse, zulururu has not updated his thread to indicate if replacing the main SMPS controller has solved the problem.

I'll be honest, I don't have any solid recommendations at this time, just suggestions.

You can repeat the measurements.

The other thread has links to sources for the main smps controller IC.

Searches for a schematic for this supply have been unsuccessful; perhaps you can have better luck.

If I had my hands on a dead BN44-00195A, I could confirm that the main smps controller is actually the problem.

PlainBill

[epicelite]

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

Maybe I derped and measured the wrong one, I will check later.

[PlainBill]

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

One other point you should check is (CM512?), the long blue cap near the main SMPS transformer. The equivalent cap was the cause of problems on the BN44-00173A power supply. One point, on the other thread, I didn't see any signs of activity out of the SMPS controller, so I wouldn't bother replacing that cap, but if your DMM measures capacitance, it definitely is worth the trouble of removing it and verifying it is good.

PlainBill

[epicelite]

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

Not sure what cap your talking about, and I don't see any other IC's to check on this thing.

[PlainBill]

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

Not sure what cap your talking about, and I don't see any other IC's to check on this thing.

Uh, huh. The cap is identified in the picture as Long Blue cap. The IC is identified as This IC and the corner pins are numbered 1, 8, 9, and 16.

PlainBill

[epicelite]

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

Ok I will give it a check.

Yeah that is the IC I checked, how the hell did I get 18?

[epicelite]

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

Blue thing, starts out at about 34V's and slowly goes down as I measure it. If I stop for a few seconds and come back it starts out at 34V's again.

[PlainBill]

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

Blue thing, starts out at about 34V's and slowly goes down as I measure it. If I stop for a few seconds and come back it starts out at 34V's again.

1. Does your meter have a capacitance range?

2. What are the numbers on the blue capacitor?

3. How are you measuring it's capacitance?

PlainBill

[epicelite]

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

Dunno.

Can't read them too well:
12 U J 630V

This is my meter, nothing special.

http://www.harborfreight.com/7-funct...01B2163195C&mr

[Toasty]

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

That meter does not have capacitance testing ability. (I have one of them.)

[epicelite]

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

I have another meter but no leads for it.

[PlainBill]

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

Dunno.

Can't read them too well:
12 U J 630V

This is my meter, nothing special.

http://www.harborfreight.com/7-funct...01B2163195C&mr

Any chance you can get a sharp picture of the numbers on the cap?

PlainBill

[epicelite]

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

Ugh can't find my camera.

It says

1 2 n J 630V
384 MMK(II or possibly an H?)

[PlainBill]

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

Ugh can't find my camera.

It says

1 2 n J 630V
384 MMK(II or possibly an H?)

Thanks for the effort. You have confirmed that it is a 12 nanofarad 5% 630 volt cap.

PlainBill

[epicelite]

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

So what's next then?

Should I redo those readings from that IC?

[PlainBill]

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

So what's next then?

Should I redo those readings from that IC?

Yes, please. After that, you have several options. Zulururu has a replacement IC on order, until he has received installed it there is no point in your duplicating the effort. If you wish to replace CM512, equivalent parts are Digikey P12114-ND, Panasonic ECW-F6123JL or DigiKey 495-3215-ND, Epcos B32672L1123J000. Each would cost under $1.00, shipping would run under $3.00 by USPS First Class Mail. And I will admit, I don't know if that will work.

I've said this before, troubleshooting this supply presents serious problems. Most SMPS supplies operate in the 70 Khz range; this one runs at 1 Mhz. I seriously doubt any DMM can react to the drive signal. On the other hand, an oscilloscope can easily see the drive signals.

PlainBill

[epicelite]

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

What if I sent you the power supply board? Or at least all the boards, dunno if you could figure the thing out without the LCD screen and backlight.

Shipping the whole thing would be like $25 and I'm too poor/cheap for that.

[Toasty]

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

Any progress?

[PlainBill]

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

Any progress?

Nothing definitive. I've received the power supply and tested it.

When I used a 2.2K resistor from S_B to PSON to turn the main supply on, it came right up. The power supply is rated at 5.3 volts at 3 amps and 24 volts at 3 amps. I tried various loads, ranging from about 1 amp on each output to over 4 amps on both outputs, and it worked perfectly.

The only conclusion I can come to is there is a short on one of the loads (signal board or inverter), which prevents the main power supply from coming up. I haven't tried shorting either output to see if that is a valid conclusion.

The only obvious problem at this point is a number of the caps had been replaced with NTE caps. A complete recapping would be required before I'd try using it in a monitor.

I did get voltage readings on the main SMPS controller at various loads, and frankly don't understand exactly what they mean.

PlainBill