Sony SMD-HS73

[torin3]

Re: Sony SMD-HS73

No real point. Just trying to say that FM has lower ESR than FC.

Ok. No problem. Just wanted to make sure I wasn't missing your point.

[retiredcaps]

Re: Sony SMD-HS73

But I'm not sure why you are telling me that FM would have lower ESR. I'm aware that relative to FC there are caps that would have lower or higher ESR specs in those can sizes.

No real point. Just trying to say that FM has lower ESR than FC.

[torin3]

Re: Sony SMD-HS73

Just remember that if the equivalent FM caps are available, they have even lower ESR.

Ok, I'm apparently completely missing the point you are making.

Since I've already replaced the caps with FC series caps I'm not planning on replacing them again unless they go bad. I don't know what brand/series were on there originally, so I can't say for certain that they are out of spec, but again, going by FC specs, they certainly seem to be going bad. Especially since 3 other caps, including at least 1 more 47uF cap all tested much lower.

But I'm not sure why you are telling me that FM would have lower ESR. I'm aware that relative to FC there are caps that would have lower or higher ESR specs in those can sizes.

[retiredcaps]

Re: Sony SMD-HS73

The 10uf cap was at 15Ω, as opposed to the FC spec at 3Ω. The 47uf caps were at 6.2Ω & 7.3Ω compared to the FC spec at 1Ω.

Just remember that if the equivalent FM caps are available, they have even lower ESR.

[torin3]

Re: Sony SMD-HS73

Sorry I haven't been working on this one while I was waiting for my Blue ESR meter kit to arrive. I came in Monday and I put it together last night. I seem to have gotten it right the first time.

Anyway, I've been testing some of the caps I pulled off this board. It has been long enough that I'm not 100% sure of which through-hole caps were from this board, but for the logic board, it was the only one I removed SMD caps from. 3 of them seemed to be likely bad based off of the FC series data sheets. (I can't tell what brand, the only markings other than voltage and capacitance is what looks like 30I1 on the 47uF, and 3a on the 10uf cap, all 16v.)

The 10uf cap was at 15Ω, as opposed to the FC spec at 3Ω. The 47uf caps were at 6.2Ω & 7.3Ω compared to the FC spec at 1Ω.

I should be working more on this board over the weekend. I'll be trying to trace down possibly bad components on the board.

[torin3]

Re: Sony SMD-HS73

What is the model number for Q3?

SSS6N70A 341
http://www.alldatasheet.com/datashee.../SSS6N70A.html

Sorry, one more. What is the part number for the diode that is providing the 12V rail? It will be one of the two that is mounted on the heatsink.

I had to remove the cap from in front of it to get the number...

UD6340 STPS10 150 CT

http://www.alldatasheet.com/datashee...STPS10150.html

[retiredcaps]

Re: Sony SMD-HS73

Sorry, one more. What is the part number for the diode that is providing the 12V rail? It will be one of the two that is mounted on the heatsink.

[retiredcaps]

Re: Sony SMD-HS73

What is the model number for Q3?

[torin3]

Re: Sony SMD-HS73

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

200D6 PZDC

This looks like it should be right.
http://www.alldatasheet.com/datashee...1200D60R2.html

[retiredcaps]

Re: Sony SMD-HS73

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

[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.

[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

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.

[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.

[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

[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?

[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.

[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

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.

[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?