Sony SMD-HS73

[jetadm123]

Re: Sony SMD-HS73

I could be wrong, but Q7 may not be a transistor, but some sort of voltage detector. Referring to spec sheet, pin1=5V and pin3=4.2V. Try measuring for these voltages.

[torin3]

Re: Sony SMD-HS73

I could be wrong, but Q7 may not be a transistor, but some sort of voltage detector. Referring to spec sheet, pin1=5V and pin3=4.2V. Try measuring for these voltages.

Pin 1 to 2 = 4.39 VDC
Pin 3 to 2 = 1.17VDC with lamp off, up to 5.7VDC with lamp on.

[alexanna]

Re: Sony SMD-HS73

This inverter controller has been discused look at the last 2 posts.
No fix was listed but an explantion of how the oz960 works.
https://www.badcaps.net/forum/showth...ighlight=oz960
Al.

[jetadm123]

Re: Sony SMD-HS73

Pin 1 to 2 = 4.39 VDC
Pin 3 to 2 = 1.17VDC with lamp off, up to 5.7VDC with lamp on.

Try measuring the same points using a different ground. If you get a voltage on pin 2, I either guessed wrong on what Q7 is or it may be defective.

[torin3]

Re: Sony SMD-HS73

Try measuring the same points using a different ground. If you get a voltage on pin 2, I either guessed wrong on what Q7 is or it may be defective.

Same readings using a ground point near CN1.

Ground to pin 2 is 0.00VDC.

[alexanna]

Re: Sony SMD-HS73

Off = .12V
On = .14V
Light on, hard to tell with my slow meter, but it looks like close to 5V.

I think you are going to find a problem with the logic board. Could you re check the voltages on the on off pin at CN1?
If you look at page 2 of the data sheet of the oz960 the enable or the on off voltage is 2 to 3.3volts when on.[you have to lay your head on your left shoulder to read it].
I think I would also take a closer look at the voltage regulators on the logic board, monitor the output voltages as you power the monitor on and do it several times.
I really don't know if this is the answer it's just something to try.
Al

[torin3]

Re: Sony SMD-HS73

I think you are going to find a problem with the logic board. Could you re check the voltages on the on off pin at CN1?
If you look at page 2 of the data sheet of the oz960 the enable or the on off voltage is 2 to 3.3volts when on.[you have to lay your head on your left shoulder to read it].
I think I would also take a closer look at the voltage regulators on the logic board, monitor the output voltages as you power the monitor on and do it several times.
I really don't know if this is the answer it's just something to try.
Al

Voltages at the on/off pin are the same as before at CN1.

Checking the Enable voltage from the oz960, I'm getting 1.17V for off, then frequent drops to about .5V.

Should I be looking between pin 3 for U1 and the on/off location at CN1 for possible bad components? Or should I consider getting a replacement oz960?

Also, the two voltage regulators on the logic board. 3.3V seems to be pretty close to that. When on, a steady 3.34V when off steady 3.37V. The 1.8V chips bounces between 1.09V and 1.24V when left on. When turned off, it goes immediately to 2.35V and gradually works it way up to 2.48V and stays steady there. When turned on it goes to 1.17V for a second or two before bouncing between the 1.09V and the 1.24V.

[alexanna]

Re: Sony SMD-HS73

Voltages at the on/off pin are the same as before at CN1.

Checking the Enable voltage from the oz960, I'm getting 1.17V for off, then frequent drops to about .5V.

Should I be looking between pin 3 for U1 and the on/off location at CN1 for possible bad components? Or should I consider getting a replacement oz960?

Also, the two voltage regulators on the logic board. 3.3V seems to be pretty close to that. When on, a steady 3.34V when off steady 3.37V. The 1.8V chips bounces between 1.09V and 1.24V when left on. When turned off, it goes immediately to 2.35V and gradually works it way up to 2.48V and stays steady there. When turned on it goes to 1.17V for a second or two before bouncing between the 1.09V and the 1.24V.

The 1.8 volt regulator may be a problem,
I am going to ask for help on it, let's see what the other guys say
Al

[retiredcaps]

Re: Sony SMD-HS73

Also, the two voltage regulators on the logic board.The 1.8V chips bounces between 1.09V and 1.24V when left on. When turned off, it goes immediately to 2.35V and gradually works it way up to 2.48V and stays steady there. When turned on it goes to 1.17V for a second or two before bouncing between the 1.09V and the 1.24V.

I'm a bit confused and it is almost 1am in the morning, but back in post #9, the regulators were identified as 1086D25 a 2.5V regulator and BA033 a 3.3V regulator. Where did 1.8 come from?

[torin3]

Re: Sony SMD-HS73

I'm a bit confused and it is almost 1am in the morning, but back in post #9, the regulators were identified as 1086D25 a 2.5V regulator and BA033 a 3.3V regulator. Where did 1.8 come from?

I was up late and tired too and reading the wrong leg on the regulator?

[torin3]

Re: Sony SMD-HS73

I'm a bit confused and it is almost 1am in the morning, but back in post #9, the regulators were identified as 1086D25 a 2.5V regulator and BA033 a 3.3V regulator. Where did 1.8 come from?

Ok, I had a chance to remeasure this morning. I was reading the wrong leg. Between ground and Vout I'm get about (If I'm remembering right, I'll check again when I get home) about 2.63V. It is rock steady when on or off or the lamp coming on or off.

Checking the datasheet, if my memory is correct, the voltage looks a little high.

[PlainBill]

Re: Sony SMD-HS73

Ok, I had a chance to remeasure this morning. I was reading the wrong leg. Between ground and Vout I'm get about (If I'm remembering right, I'll check again when I get home) about 2.63V. It is rock steady when on or off or the lamp coming on or off.

Checking the datasheet, if my memory is correct, the voltage looks a little high.

It is. The LDO regulators are usually specified as +- 1%. It's either the regulator or your meter.

PlainBill

[torin3]

Re: Sony SMD-HS73

It is. The LDO regulators are usually specified as +- 1%. It's either the regulator or your meter.

PlainBill

I wouldn't be surpised at all if it was my meter. I've got 2 cheapie meters, and I'll try with both of them when I get back home today. On the presumption that even if both meters are inaccurate, they aren't likely to be inaccurate in exactly the same way and amount of error.

I should probably get a better multimeter for when I need accuracy rather than continuity checks.

But it will have to wait until after I get my ESR meter kit.

[retiredcaps]

Re: Sony SMD-HS73

I wouldn't be surpised at all if it was my meter. I've got 2 cheapie meters, and I'll try with both of them when I get back home today.

Back in post #9, you measured the 5V rail as 5.05V DC stable and you measured the regulator as 2.48V

PlainBill says that the 5V rail is usually regulated.

So 1.01 (1%) x 5.0 = 5.05V.

1.01 (1%) x 2.5 = 2.525V
0.99 (-1%) x2.5 = 2.475V

So I think the multimeter that you used in post #9 is okay?

Something has changed since then to cause this higher voltage reading (17V and now 2.63V). We had one case a few days back where the battery in the multimeter was low and causing funny readings. You may want to try a fresh battery?

[PlainBill]

Re: Sony SMD-HS73

Back in post #9, you measured the 5V rail as 5.05V DC stable and you measured the regulator as 2.48V

PlainBill says that the 5V rail is usually regulated.

So 1.01 (1%) x 5.0 = 5.05V.

1.01 (1%) x 2.5 = 2.525V
0.99 (-1%) x2.5 = 2.475V

So I think the multimeter that you used in post #9 is okay?

Something has changed since then to cause this higher voltage reading (17V and now 2.63V). We had one case a few days back where the battery in the multimeter was low and causing funny readings. You may want to try a fresh battery?

A correction, retiredcaps. LDO regulators, such as the AS1117-3.3, etc are spec'd +-1%. The 5V output is regulated, but the actual voltage is determined by a number of components added by the monitor manufacturer.
I'd expect it to be within 5%, but is often deliberately set high to compensate for drop through the conductors. 5.1V is very common.

PlainBill

[jetadm123]

Re: Sony SMD-HS73

Ok, I had a chance to remeasure this morning. I was reading the wrong leg. Between ground and Vout I'm get about (If I'm remembering right, I'll check again when I get home) about 2.63V. It is rock steady when on or off or the lamp coming on or off.

Checking the datasheet, if my memory is correct, the voltage looks a little high.

What's been puzzling me is that when you measure the same voltage(s) a second time you seem to get something different each time. Like the 12V output going to 17V, the difference in the 2.5V voltage regulator output, the "bouncing" voltage feeding the CCFL controller, etc. Very confusing.

[torin3]

Re: Sony SMD-HS73

Well, either I didn't remember correctly, or like mentioned, I might have a low battery, and it might be giving me screwy readings.

2.5V regulator is at 2.49V on both meters right now. 3.3V regulator is 3.36VDC.

And just to verify, I checked the 12V rail again. Up in the 17V range when peaking.

Oh, and while it is somewhat frustrating, and I probably should be up so late before staring to work on this particular monitor, I am finding this process fascinating, and I'm learing quite a bit. Thanks again for all the help.

[alexanna]

Re: Sony SMD-HS73

Voltages at the on/off pin are the same as before at CN1.

Checking the Enable voltage from the oz960, I'm getting 1.17V for off, then frequent drops to about .5V.

Should I be looking between pin 3 for U1 and the on/off location at CN1 for possible bad components? .

What is the voltage on the enable pin #3 of oz960 when the back lights are on?
Al.

[torin3]

Re: Sony SMD-HS73

What is the voltage on the enable pin #3 of oz960 when the back lights are on?
Al.

It is hard to say. I didn't get a 1 to 1 correlation for the .5V range for when the lamps were on. The voltage drop happened more often than the lamps came on. It might be that it was trying to turn them on more often than they acutally turned on. But the lights are on and then back off again so quickly that my meter can't say for certain exactly what the voltage was when they were on. There also may be spikes of more than the 1.17V, but if so they happened so quickly it didn't register on the meter.

But the 1.17V reading was only when the light was off.

[retiredcaps]

Re: Sony SMD-HS73

Just out of curiousity, what is the part number for IC2 on the backside of the power board?