HP w2007 PTB-1773 - Where to start?

[PlainBill]

Re: HP w2007 PTB-1773 - Where to start?

That measures 160.1 v.

Very interesting. That brings up some important questions.

1. What is the voltage across the two points I have circled in yellow?

2. It's a little hard to make out the details of that portion of the circuit board. Could you try to take a better picture of the area I have outlined in brown.

3. The datasheet for the (presumed) SMPS controller is here http://pdf1.alldatasheet.com/datashe...TEA1530AT.html Page 15 has outline information. Could you please confirm the orientation of the IC.

PlainBill

[maverick530]

Re: HP w2007 PTB-1773 - Where to start?

#1 - 0.77 v
#2 - See Attached. Is this detailed view better?
#3 - The writing on the IC is upside down in the attached picture. Does that mean pin 1 is the top right pin? If so, I should also be checking across pin 1 +(Vcc) and pin 2 - (GND) instead of 1 & 3 right?

[PlainBill]

Re: HP w2007 PTB-1773 - Where to start?

#1 - 0.77 v
#2 - See Attached. Is this detailed view better?
#3 - The writing on the IC is upside down in the attached picture. Does that mean pin 1 is the top right pin? If so, I should also be checking across pin 1 +(Vcc) and pin 2 - (GND) instead of 1 & 3 right?

The voltage reading indicates there is a problem with the IC. I am almost certain we have NOT identified it correctly. It'll be a few days before I can get back to this. In the meantime, please try to identify where each pin of the IC goes.

PlainBill

[maverick530]

Re: HP w2007 PTB-1773 - Where to start?

I don't quite understand how we know the IC is bad due to that voltage reading. That voltage reading is simply the voltage on resistor R804 leading up to the IC.

However, I did re-probe the IC with what I now believe is VCC and GND and I get nothing--which DOES indicate a failure of the IC, right?

Any luck finding out what IC this is exactly?

[PlainBill]

Re: HP w2007 PTB-1773 - Where to start?

I don't quite understand how we know the IC is bad due to that voltage reading. That voltage reading is simply the voltage on resistor R804 leading up to the IC.

However, I did re-probe the IC with what I now believe is VCC and GND and I get nothing--which DOES indicate a failure of the IC, right?

Any luck finding out what IC this is exactly?

OK, my thought process went this way: Most SMPS controllers use a resistor from the main line filter capacitor to the 'start up power' pin. Typically that pin is rated for an absolute maximum voltage of less than 35 volts, and a typical voltage of 20 volts (This varies widely from one chip design to another). In this design, R804 provides start up power to the SMPS controller. Looking at R804 on the top side of the board, it appears to have brown, green, orange, and gold bands (reading color codes is tricky even in pictures as good as these). That would give a value of 15K 5% if I still remember the menomic (bad boys rape our young girls but Viola gives willingly). A .7 volt drop across a 15K resistor gives a current of .05 ma - far too small.

As far as identifying the IC, any progress will depend on you. I've marked up the picture of this area, and need help identifying which pins of the IC go to certain points. I've indicated what should be pins 1, 4, 5, and 8 of the SMPS controller, as well as points A, B, C, D. See if you can determine which pins of the IC are connected to those 4 points.

Also, please confirm the color bands on R804. If you have a good magnifier or a low poer microscope available, the part number of the IC would be a big help.

PlainBill

[maverick530]

Re: HP w2007 PTB-1773 - Where to start?

ok, do you have that picture labeling points A B C & D?

[PlainBill]

Re: HP w2007 PTB-1773 - Where to start?

ok, do you have that picture labeling points A B C & D?

Duh!!! One more senior moment in a day full of them.

PlainBill

[maverick530]

Re: HP w2007 PTB-1773 - Where to start?

The bands on R804 (from left to right) are Gold?, Orange, Green and Brown.

[maverick530]

Re: HP w2007 PTB-1773 - Where to start?

I got a 10x Loupe and my close up lense and I'm fairly certain about the top right number being 1530A (see pic), which is the most important, right?

My best deciphering says IC801 is:

CA1530A
6S1DZ02
HnG7311

Line 1 didn't change. Line 2 changed most with more confidence. The first character on the 3rd line is a bit fuzzy, it could even read WnG7311.

[maverick530]

Re: HP w2007 PTB-1773 - Where to start?

Ok,

I probed the board via continuity test, and found that:

A maps to pin 6
B maps to C (otherwise couldn't find pin mappings for these B or C)
D maps to pin 2

Is there any other test I can do to better map B and C or is this enough to go off of? What does this tell us?

BTW, here's a link to my new MY-69 DMM! ! So far, it's been great!

[PlainBill]

Re: HP w2007 PTB-1773 - Where to start?

I got a 10x Loupe and my close up lense and I'm fairly certain about the top right number being 1530A (see pic), which is the most important, right?

My best deciphering says IC801 is:

CA1530A
6S1DZ02
HnG7311

Line 1 didn't change. Line 2 changed most with more confidence. The first character on the 3rd line is a bit fuzzy, it could even read WnG7311.

I keep coming back to the same point. The only number that begins to make any sense is CA1530A. It's a heck of a big leap, because even then it must be a partial number -the full number would be TEA1530AT.

Let's try a few points. Earlier I had identified the pins of IC801, and labeled 4 points. With power off, measure the resistance between points A thru D and pins 1 thru 8 of IC801. Use the lowest resistance scale on your DMM, ignore any reading that is off scale. If pin 2 is NOT connected to point D, this cannot be a TEA1530AT. As a further check, point A should be connected to pin 6.

EDIT: Whoops, I see you have already done this. Great!!! That appears to confirm the identity of the IC. It is now rapidly approaching my bedtime. I'll come up with voltage measurements to make tomorrow.

PlainBill

[PlainBill]

Re: HP w2007 PTB-1773 - Where to start?

Ok,

I probed the board via continuity test, and found that:

A maps to pin 6
B maps to C (otherwise couldn't find pin mappings for these B or C)
D maps to pin 2

Is there any other test I can do to better map B and C or is this enough to go off of? What does this tell us?

BTW, here's a link to my new MY-69 DMM! ! So far, it's been great!

With the power supply plugged in, try measuring voltages from pin 2 (black lead) to the other 7 pins. Pin 8 should be about 160 volts, others should be mush lower. I'm particularly interested in any signs the voltages are fluctuating (a sign the controller is trying to start up).

PlainBill

[maverick530]

Re: HP w2007 PTB-1773 - Where to start?

Voltages from pin 2 (negative black) to pin:

1 - -15.7mV
3 - -.1mV
4 - 0
5 - 0
6 - .051v
7 - .007v
8 - 159.5v

So I do get the 160v between 2 & 8 you expected, but no real signs of voltage fluctuation. The only fluctuation I saw was a steadily increasing voltage on pins 6 & 7 probably due to my "Auto" sensing scale DMM. When I set it to V (not auto scale) it gave those solid readings above.

[maverick530]

Re: HP w2007 PTB-1773 - Where to start?

Does this mean IC801 is bad? Should I go ahead and order one? If so, I'll get the order in immediately as HKin takes weeks.

[PlainBill]

Re: HP w2007 PTB-1773 - Where to start?

Does this mean IC801 is bad? Should I go ahead and order one? If so, I'll get the order in immediately as HKin takes weeks.

Not quite yet. I'm well outside my comfort zone here and have been trying to figure out how to troubleshoot this thing. It's a lot easier when I have both good and bad circuit boards in front of me and a scope and dmm to use to compare the two.

Rather than concentrate on the controller, I'm going to have you look at the surrounding components. In the attached picture the blue circles are all semiconductors. Use the diode setting on your meter and make sure the diodes show conductivity in only one direction. Q803 is the power FET, check in both directions from each pin to the other two pins. This may or may not show conductivity. The main thing is that it is not shorted.

The red ovals are for resistors. Compare the resistance to the value of the component. And the black circles are solder joints that don't look all that healthy. Heck, better check the solder joints on Q803 too.

PlainBill

[maverick530]

Re: HP w2007 PTB-1773 - Where to start?

Ok, I checked the Semiconductors. I've labeled the values and polarities on the attached diagram.

The only one that seems odd is D806, that reads .080 in both directions!

Q803 looks ok, even though I don't get any reading in any direction from G to D.

Will check the resistors shortly.

[PlainBill]

Re: HP w2007 PTB-1773 - Where to start?

Ok, I checked the Semiconductors. I've labeled the values and polarities on the attached diagram.

The only one that seems odd is D806, that reads .080 in both directions!

Q803 looks ok, even though I don't get any reading in any direction from G to D.

Will check the resistors shortly.

It looks like R813 and R814 are across D806. That might explain the reading on D806. Q803 probably is good. I have problems figuring out FETs.

PlainBill

[maverick530]

Re: HP w2007 PTB-1773 - Where to start?

How do you know what polarity to test Resistors? I've marked up the diagram with both values (if different).

Not sure how to read what R814's value should be. It's markings are (from left to right): Gold Black Orange Orange. It reads 21.8 ohms in either direction.

R803 reads .6 ohms (rated for .51 ohms)
R805 reads 100.6K ohms (rated for 100k ohms)
R811 reads .5 ohms (rated for .27 ohms)
R814 reads 21.8 ohms (rated for ??)

See anything wrong with these values?

[PlainBill]

Re: HP w2007 PTB-1773 - Where to start?

How do you know what polarity to test Resistors? I've marked up the diagram with both values (if different).

Not sure how to read what R814's value should be. It's markings are (from left to right): Gold Black Orange Orange. It reads 21.8 ohms in either direction.

R803 reads .6 ohms (rated for .51 ohms)
R805 reads 100.6K ohms (rated for 100k ohms)
R811 reads .5 ohms (rated for .27 ohms)
R814 reads 21.8 ohms (rated for ??)

See anything wrong with these values?

Out of circuit, resistors don't have polarity. In circuit could be another matter. You were reading the color bands of R814 in reverse order. Orange, orange, black, gold is 33 ohms, 5% tolerance. Whoops!! Are those bands orange or red? Red would mean it is 22 ohms.

OK, I looked at the picture in the first post and it looks like red, red, black, gold to me.

At this point my best guess is that I801 is bad.

PlainBill

[maverick530]

Re: HP w2007 PTB-1773 - Where to start?

Ok, I will order the TEA1530AT; Anybody know where I can purchase this or do I have to do the month-long HKin.com process (too expensive to pay for tracked 3 day shipping)?