EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: perdrix on January 27, 2021, 10:58:00 am
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Hi all,
Following my recent experience with the serial EEPROM in my GPIB-USB-HS losing its memory, I thought I should open up my GPIB-USB-HS+ and take an image of its EEPROM.
Unfortunately I've failed at the "first base" - undo two Philips screws, and then what? Case doesn't want to open and I don't wish to break it! I thought there might be another screw under of the labels, but if there is, I can't find it by the usual trick of pressing on the label which normally reveals the location of screws or screw holes.
Does anyone know how to get inside these?
Thanks
David
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Maybe it's just a bit stuck.
Tap those fingerscrews simultanously towards the opposite sides of the case.
Is it even hinting?
You can also stuff something between a screw and a case from the back.
Usually you will also leave a mark.
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No obvious clips - I've pried the case apart in numerous locations, so far w/o success.
D.
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You see some photos on google
This site shows 4 screws holes ??
https://xdevs.com/guide/ni_gpib_rpi/
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The one with 4 holes is the GPIB-USB-HS, not the GPIB-USB-HS+
They are quite different. This is what an HS+ looks like:
(https://images-na.ssl-images-amazon.com/images/I/61NdRQCwQGL._SL1000_.jpg)
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No screw(s) under the sticker/label?
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Not AFAICT (see first post).
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Left side of the case in the picture is even, right side is not.
Maybe it's flipping open sideways.
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slowly insert an x-acto knife blade between the shell ??
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Apart from the fact that I used a thin bladed screwdriver rather than a knife, I already tried that :( Though I didn't "push my luck" for fear of breaking things.
D.
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Take it into the dark and scan the sticker with a red dot or UV light.
Maybe that can reveal those screws.
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Well, the two Philips screws are nothing to do with opening it! They just screw the GPIB plug to the lower case half.
The upper case half is a clip fit which is really designed to be fitted and never removed :(!
I did however manage to pry it off with minimal damage apart from a few scratches.
I attach pix so you can a) see how it fits together and b) to see what's inside - no Cypress USB ICs :(
There's just a large NI TQFP custom chip and an ST M29W800DB-70ZE6IC flash memory chip.
(https://www.eevblog.com/forum/repair/how-to-open-the-case-of-an-ni-gpib-usb-hs/?action=dlattach;attach=1163300;image)
(https://www.eevblog.com/forum/repair/how-to-open-the-case-of-an-ni-gpib-usb-hs/?action=dlattach;attach=1163304;image)
(https://www.eevblog.com/forum/repair/how-to-open-the-case-of-an-ni-gpib-usb-hs/?action=dlattach;attach=1163308;image)
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Well, it still has a circuit board.
Few discretes left and right of the memory seems like afterwads soldered.
Something programming something perhaps?
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Could be ? or a rework at the company before shipping / selling them ?
Huge cpu in there
Could you show us the other side of the pcb ??
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Huge cpu in there
Could you show us the other side of the pcb ??
Your wish is my command:
(https://www.eevblog.com/forum/repair/how-to-open-the-case-of-an-ni-gpib-usb-hs/?action=dlattach;attach=1165770;image)
Looks like J3 is intended for "bed of nails" JTAG or similar programming at the factory. The traces from pads (2, 4, 6, 8, 10) run to vias that come up under the large NI IC.
PS I tried the new "full size inline image" option for the picture but all I got for my pains was: [attachimg=1]
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Hum for an eeprom im not sure if its in the NI tqfp chip, it could even be an 1 wire eeprom ?? Ie: an sot23 transistor look a like ?
You have 2 black square ic's on each side of the usb port, and u3 near the brain chip ?? maybe it would help to get their part numbers ??
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Here's the component side again with SMD codes in red:
(https://www.eevblog.com/forum/repair/how-to-open-the-case-of-an-ni-gpib-usb-hs/?action=dlattach;attach=1173988;image)
I think the six pin parts marked 1GK are BC847CDW1T1G dual BC847, and the two pin one marked B2P may be a 3V zener. Failed to ID the rest. U3 has NO MARKING.
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My guess is that U3 is USB data something,
R36 left of it is current shunt and chip left of it is its monitor.
S-W section is probably other voltage source.
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Since this thread has such good pictures of the board of an actual GPIB-USB-HS+, I figured I'd post a picture of the board from a $150 ebay special knock off.... It actually shows up as a legit board with the current NI Visa drivers (NI-VISA 21.5).
No idea what the mystery "H08Z95" Processor is.....
(https://www.eevblog.com/forum/repair/how-to-open-the-case-of-an-ni-gpib-usb-hs/?action=dlattach;attach=1554919;image)
These guys spent a TON of time making all the packaging, labels, housings, inserts look legit. (Apart from the price) I was fooled right up until I saw the PCB.
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Renesas popped up here.
Where is its clock, behind the nylon spacer?
Missing side connector, still J3, holes are open.
Some kind of a second round thing?
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No idea what the mystery "H08Z95" Processor is.....
In some ads it is called SZ98 Chinese chip.
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Mine just showed up and uses the same H08Z95 processor with 1222 date code. Same blue, non-copper-coated case. And this thread is what comes up on Google when searching for that part
Thing is: It works with the LeCroy scope I bought it for, serial number matches from box to documents to device to advertised serial number, it does register fine with NI, and the only suspicious thing is the word "Baord" on a sticker on the (old style National Instruments) box - otherwise this would fully pass as a legit device. Of course now that I have seen the insides, I checked on the NI product registration page and it says it's a PXIe-7862 unit that needs "manual verification" - well, guess they're gonna have questions real soon.
Seller was "Amazon US" with Amazon credentials, I guess they sell/ship stuff from US sellers to Europe on their behalf. Depending on the reaction of NI, we'll see how that goes. After all, it works, so I'd actually like to keep it...
...at a slight discount >:D
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might probe with Neodymium magnet / strong magnet to detect screws while prying up by spudger which's the good one is the customized improved one by our own