Help with a component ID (pic and description)

Electronics
#1

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I wanted to reach out for help locating a data sheet on these two parts. The 8pin smt dip marked ACTH and AJRG. A google search turned up nothing.

I can tell you what they’re supposed to do. The ACTH is supposed to put out one volt on the second pin from top, given an input and probably a comparator. The AJRG is supposed to do exactly the same (same pinout) at 3.3 V. I know that I am not getting 1 V in that circuit.

But I need a data sheet to see if ACTH is broken or if the problem is further upstream (incorrect inputs).

The logic chip on this board is also running exceedingly hot. And instead of 1.0V I read 0.06v I think (but not 0V). The other portions of the chip test nominally so far. I do not have schematics. But I do have a working copy to compare.

#2

I should clarify, it appears to be an adjustable Vreg chip, because as you can see from the test point top left, you get 2.5 V off the same AJRG chip, that does 3.3 elsewhere.

I can go into more detail as to what I measure on each pin, but I don’t think it’ll help. I don’t have a scope, just a cheap multimeter.

#3

Those look like buck converters. Check pin 2, which should be immediately to right of the one you described, and see if you have any voltage there.

Look over the board for shorts, because it sounds like it’s shorted somewhere around (or in) that really hot chip.

#4

There should be a regulator chip on your board. If so then Google that part number and look for Application Notes from that vendor. Many times the vendor’s Application Notes will have a test circuit described with component part values. You just may luck out that your circuit was designed very closely to the Application Note.

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#5

post more details about the unit, often there are service manuals available. however, I agree with michaelb - those are buck converters, and the problem is likely elsewhere.

#6

The silk screen for the ATCH chip output says 1p0V_Core (left of the inductor/choke). This implies to me this regulator is powering an SOC (likely with 3.3V I/Os which have voltage supplied by AJRG in the upper right of the photo, or possibly with 2.5V I/Os which have voltage supplied by the AJRG located along the left hand side of the photo towards the top) that has its digital logic powered by a 1V supply. I’m guessing the digital core of the unseen SOC is a power hog.

You could test the capacitors on that supply, but I wouldn’t be surprised in the least if the SOC is toast.

#7

Yea. I got all that. That’s what I was trying to say

What I need is the specific pinout on ACTH. A data sheet. Then I can see if the correct voltage is going in. If so, then acth is the culprit. If not then I need to go further upstream and find out where the inputs are coming from. For now I’ve traced the error to that specific section the 1V power supply for the logic.

It’s not that it’s a logic hog- per Se. as I mentioned, I have a (2 actually) working one(s). So, I can see that the voltage vs ground at the visible test point is in fact 1 V on a working chip. And it’s 0.06 in this broken one. So I think it’s likely the IC. Capacitors are solid state by looks and are unlikely to blame

I don’t have an easy way to test the caps at hand either. But I could peg it to the the caps with a data sheet. It worked at one point and stopped.

What I am specifically looking for is a data sheet or advice on how to find a data sheet given that imprint. In the past I’ve just looked up the imprint to find the part. Or there’s a standard (R, L, C). This one ACTH- I’m at a loss for. No hits in searching online. Maybe ACTH is a standard I am unfamiliar with that gives away its ID. Or maybe someone’s seen it. I can’t even order a replacement from mouser because I don’t know what it is.

#8

The unit is a MoCA adapter. Basically an Ethernet to coax converter for sending Ethernet lan through an existing home coax cable installation. They’re rather expensive. There is almost no documentation for them. And there really isn’t any support. Only 2 companies make them. Motorola and this company (who’s name currently escapes me). It’s not one you’d recognized because nearly all their business is selling to companies like time warner cable for home installs.

I can take a wider angle shot but it would lack detail. But there is a large logic ic under a perm affixed heat sink. If it goes under there I’ll probably just give it up.

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#9

I’m not seeing the chip in question in the pic. Can you post a zoomed out version of that as well?

#10

There’s no standard code, it’s a combination of luck and more luck to find the part number from that case.

Good news is you don’t need a datasheet to know that on the ATCH part the second pin from the right on top (pin 2 if you’re numbering traditionally) is the power going in to the chip.

#11

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Although maybe there is a short under there and that’s th reason the sink is getting so hot.

Pin 2 is the out V- at 0.06.

It’s likely a buck Converter of some type. Going in are 2 5V pins (6 and 7) and a 7.5V (p8), 2 ground, and 1 NC or another signal that seems to float. There are lots of kinds of buck converters though. Mouser has something like 27,000 of them :), sure when you pare it down to 8pin SMT, of roughly that size and an output V in the 1V range it’s a manageable number. That might be my next step, just clicking through the results, of which there will prob be a few hundred

#12

Pin 3 is the pin going to the inductor. I assume that’s the pin that has 0.06v on it (though it doesn’t really, it has a switching waveform you can’t see with a meter). Pin 2 is connected to the two capacitors C212 and C213. The horizontal line indicates the top of the part so the pin on the left end of the line is 1 and the right is 8. The dot on the silkscreen at the top left of the other part confirms this.

#13

I was looking for documentation on the product … perhaps a schematic

I found this in the User Manual …
LOL

Important Safety Instructions
Basic safety precautions should always be followed to reduce the risk of
fire, electrical shock, and personal injury, including the following:

  • Do not use this product near water – for example, near a bathtub,
    kitchen sink, laundry tub, or swimming pool, or in a wet basement;
    only clean with dry cloth.
  • Do not block any ventilation openings. Install in accordance with the
    manufacturer’s instructions. Do not install near any heat sources such
    as radiators, heat registers, stoves, or other apparatus including
    amplifiers that produce heat.
  • Do not use the telephone to report a gas leak in the vicinity of the
    leak.
  • Use only the power cord and batteries indicated in this manual if
    applicable. Note: you may need to reword for batteries or adapters.
  • Do not dispose of batteries in fire, as they may explode – check with
    local codes for possible special disposal instructions if applicable.

Full Text
… https://www.actiontec.com/wp-content/uploads/2017/01/ECB6200_UserManual.pdf
Product Web Page
… https://www.actiontec.com/products/home-networking/ecb6200/

#14

On the bottom of the circuit board the silk screen has the number E248779. This is the UL Certification number for the manufacturer of the circuit board. According to the UL database the manufacture’s name for the circuit board is:

Victory Giant Technology (Huizhou) Co Ltd.
Hangcheng Technology Area
Huiyand Area
Huizohou, Guangdong 516211 China

The above information is available from the UL website if you know where to look. It is a shame that I no longer work for UL, otherwise I would have been able to pull the file and get a copy of the schematic.

#15

What I need is the specific pinout on ACTH. A data sheet. Then I can see if the correct voltage is going in. If so, then acth is the culprit. If not then I need to go further upstream and find out where the inputs are coming from. For now I’ve traced the error to that specific section the 1V power supply for the logic.

This does not follow. What’s much more likely is that the correct voltage is going in, ACTH is doing its damndest, but a short downstream is dragging down its output voltage. It’s very unlikely for a buck converter or its support passives to have failed for no reason, and it’s usually quite obvious (think exploded chip package).

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#16

btw, pretty sure I found it for you…

your device is the ECB6200 by Actiontec, they make another device called WXB6X40Q. It has a published schematic filed with the FCC available here.

Looking at that, you can see a similar supply circuit for 1p0V_CORE using a MP1495DJ-LF-Z buck converter.

From this aliexpress listing you can see they have similar top markings, probably a date code.

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#17

This is great- thanks guys! Definitely the right direction. Haven’t had a chance to get back to this little project- but hopefully soon. Sorry I’ve been MIA. Much appreciate the schematic.

I don’t think there’s a problem with ACTH per se- it’s more of a testable breakpoint- where I know what I should measure- thus I can say the problem is either upstream in the comparator Vcc or there’s a short to ground- very likely under the heat sink. Before I tackle the heatsink though, I’m gonna have to follow up on a possible warranty claim if one so exists. Just to be sure I don’t blow that.

After that, I may simply lack the skill to follow this all the way to the fault. And the equipment. I’ve been looking for a cheap, perhaps computer connected scope/ multimeter and microscope so I can do some more advanced work at home. It’s hard to justify the cost at this point because my fix rate is so low, It rarely makes sense.