[SOLVED] CMU200 problem with INVALID parameters - Page 1
Forum section: electronics / testgear

author: om4ik
author_rank: Contributor
timestamp: April 03, 2020, 08:58:07 am
content: HiSorry for extensive topic message but it is important for detailed description of my problem.I have got CMU 200 with PC from CRTU FMR6 (Pentium 933 MHz) with basic configuration (only B11 OCXO installed). Bios is CRTU-RU v0.91 and BASE v5.21. Two weeks ago I have got problem with cycling on and off so I disassemble machine and measure. Problem was on membrane (power switch pin has electric leakage with another) and that was reason why machine powering on and off. I interrupt this connection on membrane connector and solder paralel 2 wires for switch to pins on PC board. I disconnect also CMOS battery because I dont want to solder to board with voltage. Then a install battery back and try to power on machine. Problem with on and off disappear but appear a new problem. Machine power up I press F1 for default CMOS parameters then machine boots up and looks like OK. After 3 min appear an error message : "Temperature measurement aborted !" FANs goes to max RPM ant after clicking ENTER it drops to MSDOS. After restarting situations repeat with same symptoms (3min ok, error, fan max...) so after boots up I have about 3 mins to trying anything. I try measure spectrum it looks OK, I try to start rf generator and also it is ok, Power meter OK but after 3 mins error stop the program. I try to make selftests and there are some errors. Eeprom reading of all boards are OK but measured voltages, temperatures, NETCLKs etc. has only INVALID value on all parameters on DIGI board and also on FE board. When I try to selftest REF board eeprom is ok but after eeprom OK value appear error window with message : "Unsyncs recalibs not supported" and machine must be restarted. When I try to selftest RXTX board there are no problems eeprom ok also measured parameters (temp voltages...) are OK too (no red or invalid). When I try to test RFloops also it is OK. I disasemble it again and inspect for any short circuit or damaged connector pins but nothing found. I try to update firmware, reinstall base, downgrad base to older also I try to format HDD and reinstall a new SW but still same problem. Only what I not try is flash bios from CRTU v 0.91 to CMU 200 because I dont know where to download it for FMR6 P933MHz. But I thing it is not reason because bios was same before this issue appear and it works. Only what I do was change battery from CMOS but I click to default CRTU. Maybe on CMU bios there are another default setting.I thing problem looks like there is problem only on diagnostic parameters because main measuring parameters are OK. I think this is reason why error temperature measuring aborted appear because main SW havent info about temperature of machine. Also when I run FM calibration it looks OK but when I look better there are temperature 0 on all parameters. But on service manual there are little informations about procedure of selftest parameters so I dont know how it works if there is special bus for this or why RXTX board measuring selftest good but other boards INVALID values. On manual is information the DIGI board has AD converter for diagnostic parameters of CMU boards monitoring but whu RXTX has good parametrrs and DIG and FE and REF has problem.Any idea where could be a problem ? Is there any information with scheme of mainboard and other boards connections ? Have anybody CMU200 FMR6 bios dump file please ?Thanx for any ideas. I dont know what to do next.OM4IK IgorPS: I also measure all PSU voltages on mainboard pads near green leds and also 5V reference but all OK. Also checked coaxial connection between all boards with no problems.

author: om4ik
author_rank: Contributor
timestamp: April 09, 2020, 05:45:03 am
content: Can someone help me with take a photo of default bios settings of CMU200 ? Very helpful will be to take a photo of all submenus please).Thanx

author: _Wim_
author_rank: Super Contributor
timestamp: April 09, 2020, 07:55:26 am
content: Here you are. Hope you can fix the problem

author: om4ik
author_rank: Contributor
timestamp: April 11, 2020, 10:45:51 am
content: Thanx very much Wim. 80% parameters are same but in my Bios there are some parameters there is not present on your bios and also on your are some what is not on my. Anyway I try to set everything what was able to set to your setting but problem is still here. What CPU and bios version do you have Wim ? I have Pentium 3 933MHz and Bios FMR6plus v0.91 for CRTU-RU (see photo). Can you also take a photo please ?Thanx

author: _Wim_
author_rank: Super Contributor
timestamp: April 11, 2020, 11:49:49 am
content: Quote from: om4ik on April 11, 2020, 10:45:51 amThis is my version.

author: Ice-Tea
author_rank: Super Contributor
timestamp: April 11, 2020, 11:54:41 am
content: Somehow, you seem to have received a CRTU "head" on a CMU? Very odd...Accidently, both the CMU and CRTU (but CRTU a bit more) have issues with dry caps around the CPU. You may want to look into that? I assume that the CPU had its own fan? In that case its a CRTU board for sure.Have you considered rebuilding the SW? Can be done from the startup menu (menu select during boot)-> after board swap.

author: om4ik
author_rank: Contributor
timestamp: April 11, 2020, 03:02:14 pm
content: Thanx for replyYes it is CRTU PC in CMU200 machine (CPU has fan) but I buy it in this configuration and it works OK. After I change cmos bat on pc board the problem appear (detailed I describe it in the beginning of this topic). I also try to update firmware, downgrade and upgrade base, also I format HDD and install clear MS-DOS and also SW but without any luck. Problem with INVALID parameters in selftest in FE DIG and REF board is still there.

author: ps
author_rank: Regular Contributor
timestamp: April 14, 2020, 09:26:32 am
content: Of course you ran the "firmware update after board change" procedure from the version manager, didn't you? This collects the calibration data from each module's EEPROM and generates the parameter table on hard disk. Refer to the "Adjustment" chapter in the service manual.

author: om4ik
author_rank: Contributor
timestamp: April 15, 2020, 04:26:34 pm
content: HiYes firmware update from version manager (Menu after 3x beep) I try first and many times then (I reinstall base, downgrade version, upgrade version, reinstall MS-DOS...) but without any luck. Procedure of fw update goes OK without interrupt but after bootsup problem still there. (In selftest all board has eeprom test without problem but the second part of selftesting when parameters of voltages temperatures etc. are tested there is problem with INVALID parameters (see attached pictures in the beginning of this topic). It looks like problem with A/D converter for diagnostic data on DIG board or some missing reference. On service manual is very little informations about it. There is only information on section about DIG board there is A/D converter specialy used only for selftest diagnostic parameters from all boards converting from analog to digital. It looks like all diagnostic voltages from all boards are connected to DIG board and in this board there are converted to digital signal. But I havent got schematic so I dont know where to measure. I inspect DIG board but I find only 1 AD converter and this is connected with coax to RXTX board (measuring parameters of spectrum AD converter) but I cannot find another specialy used for diag voltages. Another secret for me is why RXTX board hasnt problem in selftest and other board has same INVALID parameters problem. Maybe RXTX has all diagnostic procedure circuits on own board and it only represent digital data to dig board but other boards represent analog values to DIG board and there is converted to digital on DIG board, but it is only my idea I am not sure how it really works. Maybe other boards has analog multiplexer which switching every parameter to 1 input synchronized by actual step of selftest procedure I dont know. There must be one common thing for selftest FE DIG and REF and not common for RXTX because this boards has same selftest problem and RXTX not. I try to measure all pins of 34 pin connector on FE board by the selftest running but I cannot find any pins where the voltage was changing synchronous with selftest steps goings on. Its very difficult to repairing without schematic and right idea how it works.

author: om4ik
author_rank: Contributor
timestamp: December 28, 2020, 04:10:26 pm
content: HiI solved it. The problem was on DIGI board. On this board is A/D converter for diagnostic voltages multiplexed by every board except RXTX (this board has its own diagnostic engine) and paralel connected to one signal wire. Also DIGI board has own multiplexer for its selfdiagnostic. This A/D converter and some transistors on voltage reference circuit for this converter and also 4xamplifier also was faulty. I havent got another board so i must repaired this one and now everything is OK. Repairing was not simple and describing also. Schematic diagram is impossible to find for this board so I do some reverse engineering of DIGI board and I have got some circuit schematic painted with my hand on many papers so I have plan to write post about this repairing and also with photos I public it on my personal blog. Then I inform about link to this post.Thanx to everyone with helping me.Stay safe and 73 on hamradio band.OM4IK

author: _Wim_
author_rank: Super Contributor
timestamp: December 28, 2020, 06:50:20 pm
content: Quote from: om4ik on December 28, 2020, 04:10:26 pmCongratulations! That must not have been easy!

author: om4ik
author_rank: Contributor
timestamp: December 29, 2020, 02:14:31 pm
content: Thanx9 month I repairing it but with long pauses also. Life isnt easy so repairing also not but now I am much happy ☺.

author: ven
author_rank: Newbie
timestamp: July 10, 2023, 04:55:21 pm
content: Looking forward to your article on this fix。