Wacom cintiq dtz-2100 power issue (need ideas)

[chicago77]

Good evening. I figure you can find anything on the internet, but I've been stumped.

I have a Wacom cintiq 2100k I acquired that randomly powers off. When you let it sit for a while unplugged it powers up generally on the first try and will stay on for a few minutes. It then goes completely dead (no lights). If I wait, it normally comes back on after a minute or so and then repeats. Generally it powers off faster and stays off longer if I leave it plugged in.

I've done some debug by unplugging boards one at a time and I believe I have narrowed it down to the middle board that has the 12V input and DVI plug. Nothing looks obviously bad and the 12V in seems to be good.

I was thinking about replacing the DVI chip (gm5862h-lf AA) but I haven't found a place to order it, nor do I know if it has any vendor loaded code on it. Does anyone have familiarity with this chip? There 2 SDRAM chips next to it I assume it boots from. I was also considering hitting the oscillator with some LN2 to see if it was failing as it heated up. Nothing really seems to be getting too hot.

Does anyone know where I could find a replacement board? I checked ebay and was shocked there was nothing there.

Id also love to just fix this board if anyone has any ideas. I have access to a re-flow machine. So I should be able to swap any part on the board if I can get it. Do you guys have any idea what I should look for to narrow it down? I'm pretty handy with a multimeter, but am lost without a schematic.


I really appreciate the help, thank you =)

[piernov]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

Take some high-res picture of the board.
Sounds like an overheating issue, maybe a voltage regulator on the board you're talking about.

[chicago77]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

Take some high-res picture of the board.
Sounds like an overheating issue, maybe a voltage regulator on the board you're talking about.

Sorry I totally forgot to add them.

[piernov]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

I see some discoloration around IC7, but I don't see any markings on this chip?
Anyway, check the voltage on all its pins when it's working and when it stops to work.

[chicago77]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

IC7 Has readouts of GND, 1.8V out, and 3.3Vinput when the unit is working and 0V all around when it isnt. The other voltage regulator is 6.2 adj, 12V input, and 12V output when the unit is working and when it is not.

The inductors on the left is measuring 4 volts and the one of the right is at 3.3.

[chicago77]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

It appears the board looses all 3.3V when it is not functioning.

[piernov]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

Ok so you would need to trace the 3.3V line to check where it's coming. Since you mention 3.3V at the coil on the right, I guess it comes from somewhere near that, maybe IC6. What are the markings on this chip?
I still find it strange that IC7 has so much discoloration around it, it may need to be replaced.

[chicago77]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

Ok so you would need to trace the 3.3V line to check where it's coming. Since you mention 3.3V at the coil on the right, I guess it comes from somewhere near that, maybe IC6. What are the markings on this chip?
I still find it strange that IC7 has so much discoloration around it, it may need to be replaced.

I'll try to check on that when I get home. The discoloration is not as evident in real life, I think it may be just some flux residue that is getting picked up by my camera. Ill try to take a few better photos as well.

[chicago77]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

Ok so you would need to trace the 3.3V line to check where it's coming. Since you mention 3.3V at the coil on the right, I guess it comes from somewhere near that, maybe IC6. What are the markings on this chip?
I still find it strange that IC7 has so much discoloration around it, it may need to be replaced.

IC7 - M35L 1117-18
IC6 - APW7085 AN66L
IC5 - APW7085 AN66L
IC4 - APM3020P ON53R

The two caps are LF 270C

The board isnt working long enough for me to track down the 3.3 source. It looks like the IC5 and 6 chips are meant to generate this. Do you think I should just swap those out and see what happens?

[piernov]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

IC7 is a 1117, I've already seen some fail (especially under thermal stress, and that seems to be the case with the discoloration). Even though I don't think it's the issue, you can rule it out by replacing it (it's a very common part, should be easy to find).

IC6 is indeed a DC-DC buck converter so it probably generates 3.3V from a 5V or 12V source. You need to check the inputs of this component, namely VIN (pin 1) and EN (pin 2), to check if it's the source of your problem or not. VIN is probably 12V, so check that when it's not working. EN must be higher than 2.1V for this DC-DC converter to turn on, so check that as well.

You could check the same stuff on IC5.

[chicago77]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

Dumb question, but where would I source these parts I can only find the 7085 on ebay and it looks like a 2-3 turnaround on shipping.

[chicago77]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

IC7 is a 1117, I've already seen some fail (especially under thermal stress, and that seems to be the case with the discoloration). Even though I don't think it's the issue, you can rule it out by replacing it (it's a very common part, should be easy to find).

IC6 is indeed a DC-DC buck converter so it probably generates 3.3V from a 5V or 12V source. You need to check the inputs of this component, namely VIN (pin 1) and EN (pin 2), to check if it's the source of your problem or not. VIN is probably 12V, so check that when it's not working. EN must be higher than 2.1V for this DC-DC converter to turn on, so check that as well.

You could check the same stuff on IC5.

When the unit is not funcioning both ic 5 and 6 have the same outputs 1-8:
12.49, 6.29, 12.10, decaying voltage, 0, 0, 0, 0.

I only managed to get pins 5-8 on ic6 while it was working 0, .8, .55, 4.

[piernov]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

Hum… I guess "0, .8, .55, 4" is in fact from pin 8 to 5, since pin 8 is GND so it must be 0V, and pin 5 is LX which is connected to the output inductor, so it must be close to 3.3V.

If you have a low-end multimeter the measurement on pin 5 might be slighty off (as it seems to be right now) since it is switching at a high frequency. If you measure after the coil you should get 3.3V.

I'm not sure about the pin ordering of "12.49, 6.29, 12.10, decaying voltage" either. Could you check that again?

[chicago77]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

Hum… I guess "0, .8, .55, 4" is in fact from pin 8 to 5, since pin 8 is GND so it must be 0V, and pin 5 is LX which is connected to the output inductor, so it must be close to 3.3V.

If you have a low-end multimeter the measurement on pin 5 might be slighty off (as it seems to be right now) since it is switching at a high frequency. If you measure after the coil you should get 3.3V.

I'm not sure about the pin ordering of "12.49, 6.29, 12.10, decaying voltage" either. Could you check that again?

Yup, I brainfarted on 5-8 they are reveresed. That 4volts is 4v before and after the coil I have a fluke 87 which is fairly decent.

What I mean by decaying is the voltage starts around 2-3v and goes down as something in the circuit drains.

The 12.49, 6.29, 12.1, decaying order is 1-4.

[chicago77]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

Could you check that again?

I got it to turn on again long enough to take good measurements. These are correct with correct pin labeling this time

IC5 1-8 working: 12.49, 5.23, 7.00, 4.30, 4.07, 0.474, 0.797, 0.00
IC5 1-8 broken: 12.49, 0.62, 12.10, ~~~, 0.0, 0.0, 0.0, 0.0

IC6 1-8 working: 12.49, 5.23, 6.9, 4.32, 3.297, 0.540, 0.802, 0.00
IC6 1-8 broken: 12.49, 0.62, 12.10, ~~~, 0.0, 0.0, 0.0, 0.0

[piernov]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

Pins 5 to 8 at 0V obviously means that those IC aren't producing any output, it's not even trying to switch apparently.
Indeed, pin 2 (enable) is low at 0.62V when it should be higher than 2.5V for the IC to be working.
Now… Why is the enable pin low? Who knows… Maybe the scaler IC is shutting down, or maybe it is another IC. You would have to use your multimeter in continuity mode (beep) to trace out the enable signal (which probably goes through a resistor).

[chicago77]

Re: Wacom cintiq dtz-2100 power issue (need ideas)

Pins 5 to 8 at 0V obviously means that those IC aren't producing any output, it's not even trying to switch apparently.
Indeed, pin 2 (enable) is low at 0.62V when it should be higher than 2.5V for the IC to be working.
Now… Why is the enable pin low? Who knows… Maybe the scaler IC is shutting down, or maybe it is another IC. You would have to use your multimeter in continuity mode (beep) to trace out the enable signal (which probably goes through a resistor).

Can you explain how vcc works on this chip because that is also going into the weeds. Is it strange for ic5 to be sitting at 4v I'm wondering if it's shutting off due to over voltage.