Anyone knows how to replace the back case of this monitor, or how to open it properly?

It's kind of like opening a phone, the tension points are located dead center of either white sticker (top left, right), and equidistance below that.  Prying between the seal and white back case you can pop one at a time, just have a shim handy to hold one open while moving to the next. There ARE pretty tiny cables, some ribbon that are easy to bugger up, so be careful!

That said, I haven't had good luck with the available back cases, namely the lithium ion battery packs don't fit as well, and are more susceptible to powering off during normal use.  We've opted since to use the vendor repair option, but YMMV.

Thanks J. USOC sell the rear case for about 600 dollars each. But I talked to Phlips, they said customer repair is not yet available, and no parts available for MX-40. I wonder how USOC get the parts, are they OEM parts?

i talked to my supervisor and we are sending them to philips for repair.

i wonder do you have the same issue as the 4th pin on the screen side left to right always get corroded? almost all my mx-40s have some degree of corrosion on this same pin. i was thinking probably it's a design flaw.

if it was because the cleaning agent , it would make all the pins corroded not only one.

any idea?

I don't know how to upload a picture. otherwise i would like to show you.

Philips has a service bulletin out on this issue.  They are blaming it on improper cleaning:

Philips has received reports of corrosion of the patient cable connector pins on the MX40/MX4J Patient Worn Monitor (PWM). The connector pin that is most often affected is Pin 4; however, other pins can also be impacted. There may also be corrosion of the contacts inside the connector of the patient cable.

SYMPTOMS: ·

• Visible corrosion (black and/or green) ·
• Visible loss of gold plating from the pin(s) ·
• Inability of the MX40/MX4J PWM to communicate with the patient cable (“Leadset Unplugged” technical INOP) ·
• Inability of the MX40/MX4J PWM to acquire ECG and/or SpO2 signals (“ECG Leads Off”, and/or “SpO2T No Sensor” technical INOPs)

CAUSES:

Improper cleaning/disinfection of the patient cable and/or the MX40/MX4J PWM, and/or use of unapproved cleaning and disinfecting agents can cause the above noted issues, specifically:

• · Application of disinfecting products other than Isopropyl Alcohol inside the connector on the patient cable can result in corrosion and/or chemical residue build-up ·
• Application of product other than Isopropyl Alcohol inside the connector on the patient cable, followed by connection to the MX40/MX4J PWM while there is still fluid inside the patient cable connector, and then insertion of batteries into the device, will cause a reaction between the base metals of the contacts. This then results in corrosion to both the MX40/MX4J connector pins and patient cable connector contacts ·
• Application of bleach inside the connector on the patient cable results in corrosion and residue buildup on the contacts.

Service Bulletin SB86202830A provides current cleaning and disinfecting information from MX40 Instructions for Use, Release B.06.5X. Once corrosion of the pins on the MX40/MX4J PWM has occurred, it cannot be effectively removed or corrected. The device will require replacement via the Exchange Process, or for USA and Canada only, bench repair (at the Philips Lifecycle Support Center). Once corrosion of the contacts on the patient cable connector has occurred, the patient cable will need to be replaced. Note: These failures are not product quality related and do not qualify for warranty replacement/service

Thanks, Chris. I will notice the user.

But is it odd that only this pin is corroded the most?!

Their response that it is incorrect cleaning is utter garbage, it would have to affect more than one pin. We resolve the issue by cleaning off the corrosion and applying a thin film of conductive carbon grease. Has no adverse effect on the device's ability but immediately resolves the connectivity issues.

Agreed.  It is caused by a faulty leads cable in my opinion.  Philips has redisigned the cables since this notice was released and we have not seen any issues since.

"It's kind of like opening a phone, the tension points are located dead center of either white sticker (top left, right), and equidistance below that.  Prying between the seal and white back case you can pop one at a time, just have a shim handy to hold one open while moving to the next. There ARE pretty tiny cables, some ribbon that are easy to bugger up, so be careful!

That said, I haven't had good luck with the available back cases, namely the lithium ion battery packs don't fit as well, and are more susceptible to powering off during normal use.  We've opted since to use the vendor repair option, but YMMV, mentioned."

Why don't you choose YMMV?