Tech 2 Repair

[DeltaAngler]

Hello,
I have a GM Tech 2 made by Vetronics and I need a new logic board for it. Does anyone know if they are available at all and if so, where I can get one? One of the pins in memory card slot was damaged. I attempted to fix it, but apparently it is still not making a good connection. I get power on, but it doesn't do anything other than show "system initializing" and none of the other keys work.

 

[Dr.Fiero]

Is it a genuine (gag.. cough...) or one of the usual clones?

I'll lay you odds that any parts that are available would be genuine, and cost 1000 times what a whole new clone unit would be.

I managed to find JUST the unit many years ago - no cables, no case, nothing. Sometimes if you email a seller directly they'll arrange something like that.

 

[mrrsm]

Try following this Dude (His Chenglish is AWFUL ...but the Video is Good) in performing the "GYMKO" Tech 2 Self Test Procedures after removing the VCI Module and Spraying it out with CRC Electronic Component Solvent. Sometimes... just by *Cleaning & Exercising* the VCI Slide Lock Mechanism and DLC Cable installation ... you can awaken the Tech 2 from out of its Slumber.

Don't ignore the possibility of having Cracked or Poorly Soldered Lead on SMCs (Surface Mounted Components) present on the PCB after carefully disassembling the system and then using a powerful, inexpensive USB Microscope to find the errant component or corroded-dirty interface:

how to run the system self test on a tech 2 at DuckDuckGo

DuckDuckGo. Privacy, Simplified.

duckduckgo.com

Also follow up with watching all of the Tech 2 Videos presented by "Dr. Shock" at his YouTube Channel for many Step By Steps with tearing these Tech 2s apart and re-assembling them in working order:

https://www.youtube.com/results?search_query=dr.+shock+tech+2

Check out Amazon for the CRC Circuit Board Solvent:

Amazon.com: CRC 05103 QD Electronic Cleaner -11 Wt Oz: Sports & Outdoors

Buy CRC 05103 QD Electronic Cleaner -11 Wt Oz: Electrical Cleaners - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

For Related On Topic Threads:

Dead Tech 2 scanner repair.

Many thanks to this forum for the information pointing me in the right direction. I removed the small DC to DC inverter board and found a blown component, after searching 12 volt DC to DC inverter diagrams on the internet I replaced it with a .2 ohm resistor, now the scanner powers up ok but...

gmtnation.com

Tech 2 WIKI: The "Short Cuts" Step-By-Steps

This is an On-Line WIKI shows the "Short Cuts" for the Tech 2 Paths necessary to follow when stepping through each selection to achieve either Diagnostics or Changes and Updates to the PCM and Power Train Settings and/or when Updating Calibrations...

gmtnation.com

 

[Mooseman]

You do know that there is a second slot? It's just above the other one.

 

[DeltaAngler]

Thank you all for your replies to my post. I have tried your suggestions and visited recommended videos. After trying may things and cleaning up some residue flux on several parts of the board and other connections, I finally got my Tech 2 working. How ever on the "Power On Test Results", I got a Fail on URAT. What is this and what can I do to fix it? I also ran the "Automated Main PCB and VCI" test and all passed. Please help!

 

[Mooseman]

Mine fails on one of those tests but it still works. It could be for something inconsequential. If it still works, I'd ignore it.

One day I'll have to make a video of mine on boot up so I can read which one it is since it goes by so fast.

 

[mrrsm]

Unless you are using your Tech 2 Scan Tool in a Bench Top Diagnostics and Calibration or Programming Activity... It is critical to remember to ONLY Power The Tech 2 through the Power Connection situated on the DLC Connector fitted Under The Dashboard and NOT using the one located on the Lower Right Corner of the Tech 2 Unit.

 

[DeltaAngler]

I was running the Tech 2 with the AC Adapter and tried with both the bench top plug and the full cord used for the vehicle. Got the same results with both, no matter where I plug in the AC Adapter. All but one test result passed, one failed for URAT. According to my user guide when hooked up in the vehicle the cigerete lighter adapter needs to be hook up to the Adapter that plugs into the car port to insure proper grounding. I will try to research to and find out what URAT is and how to fix it, however if any one of you know please reply. Thaks for the help so far.....

 

[mrrsm]

NP... The placement of the DC Power Input Issue has more to do with lending Power directly into the DLC Port rather than through the Tech 2, since the Power Fluctuations tolerated by the OEM DC-to-DC Converter mounted arbitrarily on the PCB is Fault Tolerant in between 8 Volts DC and 18 Volts DC.

It is BEST to *** Avoid Using the Cigarette Lighter for a Power Source *** and connect the Power and Grounds directly from the Truck-SUV Battery instead. Avoid using the A/C to DC Power Converter to avoid "Bricking" the Calibration Read-Writes due to the possibility of having External A/C Radio Frequency Interference fluctuations getting inducted into the Communications Circuit.

However, the Off-The-Shelf Replacement DC-to-DC Converter replacements are NOT so forgiving and thus... directly inducing the DC Voltage into the DLC Port Pin 16 for B+ Voltage and using Pins 4 & 5 for the Body AND the PCM Ground are CRITICAL for providing the very stable Voltage needed during ANY Calibration Writes to the In-Dwelling PCM. Naturally... having a Fully Charged 12 Volt Vehicle Battery supported by a Battery Maintainer are also prerequisites here as well.

 

[mrrsm]

URAT = UART (Universal Asynchronous Receiver Transmitter)

Universal asynchronous receiver-transmitter - Wikipedia

en.wikipedia.org

The reason your are getting this UART Error is because without having a Special Loop Back Plug inserted into the RS-485 - RJ-485 Female Port on the Left side of the Tech-2 adjacent the RS-232 - RJ-45 Insert Port ...it will NOT be able to run and complete that particular portion of The System Diagnostics Tests. :>)

 

[DeltaAngler]

URAT = UART (Universal Asynchronous Receiver Transmitter)

Universal asynchronous receiver-transmitter - Wikipedia

en.wikipedia.org

The reason your are getting this UART Error is because without having a Special Loop Back Plug inserted into the RJ-485 Female Port on the Left side of the Tech-2 adjacent the RS-232 - RJ-232 Insert Port ...it will NOT be able to run and complete that particular portion of The System Diagnostics Tests. :>)

Thanks for the Info mrrsm. Do you know what type of diagnostic tests are done using the RJ-485 loop back plug? I am just wondering if that is something I may need. Also do you know if the JR-485 loop back plug is readily available online.

 

[mrrsm]

There were only Two Chinese "GYMKO" PCBs made for the various Bosch Vetronix OEM Tech 2 Knock Offs made for the NAO and European Markets. In one of the two... the RS-485 - RJ-485 inserts were meant for the OEM Bench Top Calibration Testing done during Post Manufacture and "Custom Customer Orders" Assembly. In some cases... the Chinese did NOT even bother with soldering in that port at all.

Please note that ALL of the Peripherals (RS-232, RS-485, DC-to-DC Converter and the VCI Interfaces) were added on AFTER the manufacture of the PCB Logic Boards by Hand Soldering. Thus, their Quality and Functionality can often vary a great deal... AND YET... each component can still be easily fixed by Re-Flowing their Soldered Joints if necessary.

There were also Two Variants for the Blue Skim Coated Viewing Screens, too. One used a Multi-Pin Interface to allow for the easy detachment - re-attachment of the "Blue" Screen for access to the areas underneath it... and the other was simply Hard Soldered onto the PCB. In any case, as mentioned by @Mooseman in Post #6 ...

"If it WORKS... Don't FIX It!" :>)

 

[FOOEYWUFFLE]

I don't know if this has already been covered. I bought a GM TECH-2, and didn't work right. Never been taken apart, and looks like never used. Kept showing RS232 loop-back not present. Checked the MAX232, and it seemed fine. So looked over the main board, and on the back, a Lithium battery! It was dead! Replaced and all the problems have disappeared! Will know if it is working right soon.

 

[mrrsm]

Welcome to GMT Nation...

Well Done on your Tech 2 R&R Diagnostic and Discovery of the Failed "Coin" Battery... Others of us who own Disabled Tech 2 Scanners will benefit from knowing what you have just figured out... and that making the Battery Replacement "...is worth a try" to Repair their Scan Tools.

The "RS-232 Loop-Back Tester NOT PRESENT" simply means that THIS Item was NOT plugged into the RJ-45 Port situated on the Left Side of the Tech 2 Scan Tool with the Blue Screen facing UP:

If you have any of the 4 Pair Twisted CAT-5 or CAT-6 Cable (8 Wire) Terminals and a Length of Spare Cable along with an inexpensive RJ-45 Connector Repair Kit... you can make your own version using this Wiring Pattern... literally "Looping Back" the signal transmissions used by the "GYMKO" Tech 2 during Boot-Up and the Self-Diagnostic:

An 8 Pin RJ-45 Loop-Back Clear Plastic Test Plug should be wired as follows:

Pin 2 connected to pin 7 (RTS to CTS)
Pin 4 connected to pin 5 (TxD to RxD)
Pin 1 connected to pin 8 (DTR to DSR)





Or... You can always purchase one on eBay for a mere $5.20:

Loopback Adapter Tester Plug RJ45 Network GigaBit 100MB Ethernet CAT6 | eBay

Commonly used for network administration and installation tasks, these RJ45 loopback adapter cables are a useful way to make a network device communicate with itself without carrying around a network hub.

www.ebay.com

 

[FOOEYWUFFLE]

After tracing the wiring for the RJ-45 on main board, only need 2 jumpers, 1 to 8 and 4 to 5. The other pins are 2 no connection, 3 tied to 6, but no connection to any circuit, 7 is connected to main board ground. Also had to set the internal clock to 2006 or got another fail. Tried it on H2, and found no fault codes, so I guess it works?

 

[Mooseman]

I never thought about the internal clock. I guess beyond a certain year (2013?) it doesn't work, sorta like Y2K back with some older computers. I guess 2006 works as the same as 2023. Maybe have to do the same with the laptop running Tis2000.