Pace MBT-350 LCD - Page 1
Forum section: electronics / repair

author: trapc45
author_rank: Newbie
timestamp: December 14, 2018, 02:48:07 am
content: Has anyone opened up an MBT-350? I need to replace the LCD on mine. You can only see it from the side, about a 40-60 degree angle. Of course the company that touts component level repair tools doesn't offer that as a part. They want to sell you their $700 board which is almost twice what I have in the unit to start with. Looking for a part number for the LCD if anyone has it.

author: Shock
author_rank: Super Contributor
timestamp: December 15, 2018, 01:27:25 am
content: Did you try changing the display backlight and contrast settings according to the manual?I can tell the from the color they changed the MBT 350 display a few times, hopefully no pinout differences but otherwise it looks fairly generic. I would take some good photos of the pcb front and rear to post here on the forums and take some measurements to determine pin compatibility compared to datasheets. The image below has the most recent display.Don't expect manufacturers to carry every individual component as a spare part (it's never going to happen). If you haven't already, email them and ask if they can look up the component part number of the display so you can locate a replacement. This is fairly common request when a PCB replacement is beyond economical repair.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 15, 2018, 04:15:48 am
content: It seems to be an 2x16 standard lcdon the pictureCan you remove the top case and take some photos or find any numbers on the lcd itself ??

author: trapc45
author_rank: Newbie
timestamp: December 17, 2018, 07:03:09 am
content: Unfortunately the menu adjustments have no effect. I called to inquire about the part and all they wanted to do was sell me a new board @ $500 US for what should be a $3 part. I was more than a little miffed at the irony of a company that specializes in PCB rework tools took this stance. I agree that it appears to be a vanilla 16x2 LCD. Just trying to confirm if anyone else had already done this repair and had a part number or spec. My luck is it would be some odd voltage or pinout. I guess to the healing bench she goes! It will probably be after Christmas before I get to tear in to her. We are traveling and will be gone for a few weeks. I will post up a PN or spec for posterity once done. NOT looking forward to solder wick and the the old manual sucker to get the thing off. I have become rather fond of vacuum de-soldering.

author: trapc45
author_rank: Newbie
timestamp: December 17, 2018, 07:07:30 am
content: Unfortunately disassembly will require disconnecting the vacuum assembly which I am certain is going to be a PITA. I am hoping to only have to do that once. I found a used board on fleabay for $350 out of China. The pics on the post weren't very helpful. Just what you would expect the LCD to look like. No pin marking or PNs to be seen.

author: stevelup
author_rank: Regular Contributor
timestamp: December 17, 2018, 10:06:13 pm
content: I would be absolutely astonished if that display is anything other than a bog standard $3 jobbie with a HD44780 controller.The pictures I've found suggest that it's the type with a single row header across the top rather than the double row header off to the side.These are almost always completely interchangeable - the only things to watch out for are that some generate the contrast voltage on board, and others need an external supply. And some have the LED current limiting resistors on board and the display lights up when you connect 5V to it, whereas others need a separate feed for the backlight.Both will be easy to establish once you've cracked it open.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 17, 2018, 11:28:53 pm
content: Maybe sliding the panels a little without dismantling tons of stuff would helpAs stevelup said ...If it's 1 row or dual row is a good startNormally you have 14 (without backlight) or 16 pins header (with backlight)You can search HD44780 lcd's, you will have tons of pinouts available, the only thing left is the contrast adjustment pinout to decipher, maybe an trimpot, an fixed resistor, or simply an short between the pins ?

author: trapc45
author_rank: Newbie
timestamp: January 08, 2019, 12:29:47 am
content: Thanks for the input gentlemen. I was able to weasle my way to a Pace Enginerd by calling with a rather BS technical question about this model. Once I had him on the line he offered up a source for the display, see the link below. Should be here soon. After I disassembled it (PITA) I decided I am not going to do this with solder wick, so I surfed fleabay for a few weeks and was able to pick up a pretty pristine PPS-400 for $250 and free shipping. Another $70 for a SensaTemp SX-90 (already have tips for the IntelliHeat SX-90 from the MBT-350) and this repair should be a snap. I will let you know how it turns out in a few days. Once again, thanks for the input!https://www.crystalfontz.com/product/cfah1602btmijt-16x2-character-lcd

author: james_s
author_rank: Super Contributor
timestamp: January 08, 2019, 07:20:50 am
content: That's a bog standard 44780 type character display, you can buy those all over the place, I don't think I've ever seen one that wasn't interchangeable.It's possible that the display is fine though, if the contrast adjustment does nothing then I would be more inclined to suspect the circuit that controls the contrast voltage.

author: trapc45
author_rank: Newbie
timestamp: January 14, 2019, 05:29:43 pm
content: Thanks for all the replies and input. It is vanilla 16 pin display. The link above is to the OEM part verified upon replacement and suggested as a replacement by a very helpful Pace engineer. replacement was pretty straight forward with one caveat. The power wires to the front panel ON/OFF switch were staked on. I did not fight with them and just disconnected the vacuum/pressure ports and the three connectors to the board. Removed the mounting screws and carefully backed the hand piece connectors out. They are held captive with tabs so you have to compress those and slowly wiggle the three connectors out in unison. Overall an easy repair. I got this unit for a song off fleabay. It was DoD property that was sold off through DRMO based on the paperwork. I suspect it was part of a contingency packout as it had property tags attached, but had never been used. I think the LCD itself had separated some over time and that was the issue. New display is in and everything works great. I never want to be with out a vacuum desolder capability again. I did score a great PPS-400 out of the deal so now I have a back-up station. I might swap it out and use the MBT-350 as a more portable unit since it is smaller and lighter.

author: Shock
author_rank: Super Contributor
timestamp: January 14, 2019, 08:54:23 pm
content: Good to hear you got it going. You got a PPS-400 as well that is sweet. Should take a photo of it up and running or show your setup in theShow us your soldering setup thread.

author: lmazzoli
author_rank: Newbie
timestamp: November 06, 2019, 04:59:44 pm
content: I changed two times the lcd display on two MBT 350. The only difference betweeen the popular 3$ lcd and the original one is the controller (never mind, still compliant with any HD44780 16x2 LCD) and the thickness of the entire display assembly. In order to accomodate the thinner one you must change the holding screw and the related four spacer to increase the thickness of about 4,5 mm.What breaks in the original display are the backlight diodes (two in parallel). In stead of replacing the entire display wich requires desoldering 16 pin you can just move the backlight assembly from a new display to the original one. I managed also to change just the led diode on the same original BKL diffuser once but I suggest to exchange the full assembly for a faster repair.

author: Firefly
author_rank: Newbie
timestamp: March 29, 2021, 06:40:57 pm
content: Thank you!I hate those Blue LCDs, they are junk and hard to read, I will be changing mine to black on yellow.

author: Shock
author_rank: Super Contributor
timestamp: March 30, 2021, 09:35:42 am
content: Welcome to the forum. Show us what it's like when you're done.I think this latest display they are using looks fine. I prefer not to see the matrix so I turned the brightness up and contrast down in settings (seen in the above image).

author: Firefly
author_rank: Newbie
timestamp: April 08, 2021, 08:00:13 pm
content: So much better!

author: Shock
author_rank: Super Contributor
timestamp: April 08, 2021, 09:25:56 pm
content: Firefly modded

author: djsb
author_rank: Super Contributor
timestamp: June 19, 2021, 01:39:00 pm
content: Firefly,Where did you buy your Black on yellow LCD (mines the OEM white on blue type) and was it easy to fit? I would like to change mine. Thanks.David.PS I'm based in the UK so a supplier in UK or Europe would be ideal for me. Thanks.

author: w9gb
author_rank: Contributor
timestamp: July 22, 2023, 11:05:45 am
content: Answer (and notes for install) previously posted.Crystalfontz LCD (Hitachi HD44780 standard)https://www.crystalfontz.com/product/cfah1602btmijt-16x2-character-lcdCrystalfontz America, Inc.12412 East Saltese AvenueSpokane Valley, WA 99216-0357USAHours: Monday - Friday, 8:30am - 4:30pm , Pacific TimeTelephone: +1 (509) 892-1200Fax: +1 (509) 892-1203Toll Free: +1 (888) 206-9720e-Mail: sales@crystalfontz.com

author: tooki
author_rank: Super Contributor
timestamp: July 22, 2023, 01:03:15 pm
content: Quote from: djsb on June 19, 2021, 01:39:00 pmBear in mind that that is about as bog-standard a 1602 LCD as you can get, so there are tons of compatible replacements. For example,www.buydisplay.com(which I’ve used before for TFTs) carries them in more colors, like white on black. (For one-off quantities, it may be cheaper to use buydisplay’s eBay store.)There also exist OLED drop-in replacements, though I’m not sure they’re ideal for this application, which has a lot of static text for extended periods of time.