Search MX 2424 Service Manual - Tascam blocked during Initialization.

[Herve QUEVAL]

Hi
This morning My MX2424 works perfectly, this afternoon... Blocked during initialization. Display Tascam message and stopped.... No Disk mount message.
Open the box, check power supply OK; check battery: 2.9V: replace it, not better.
Disconnect Digital I/O and Analog I/O and it works. Disk mount message and terminate with error (no I/O board).
Other test with Analog I/O and it works init is OK. I confirm it was blocked when I connect the TDIF-1 board (alone).
Factory setting do not change any thing.
Now the question is: where is the problem: mother board or TDIF-1 board?

Could some body provide the Service Manual for MX 2424. certainly some internal test to do and also schema could help to investigate

Best regards
Hervé.

 

[WarrenG]

Here ya go

Warren

 

[WarrenG]

I have a zipped file of the Schematics I have need a way to send a 5 + meg file to you. File is to large for this forum.

Warren

 

[Herve QUEVAL]

Hi Warren, have sent a private message.

 

[Herve QUEVAL]

Is there some integrated test programm in the MX-2424? How to run them from front panel?

 

[WarrenG]

Sorry your guess is a good as mine.
If you find some test sequences please let the forum know, I'm sure it could help other users.

Warren

 

[Herve QUEVAL]

for sure, I will share with the community.

 

[witzendoz]

Hi Herve,

Send me your email via a personal message and I can sheer my manuals, schematics etc with you via Dropbox.

You said you replaced the battery, is the operating system still fully installed?

Have you tried disconnecting the analog I/o and the digital I/o separately, there may be a short on one of them killing the power?

Cheers
Alan

 

[Herve QUEVAL]

Hi Alan, I send you a private message with access to my G drive.

About the battery, no issue to replace it. We loose current parameters it has no impact on operating system. The operating system is strored in a EEPROM and normaly not impacted by battery failure. I check on my machine after replacing te batery and Firmware is there (V3.01) and have to update time, date, IP address, etc...

About my failure, I did not describe correctly the problem. it is not power supply. In fact the power in on in all cases: I/O option present or disconnected.
The problem is during MX initialization:
With Analog I/O connected or no I/O connected, it works fine. Boot is OK, ready to accept command and recording. If no I/O board connected, I get error message "no board". Works fine.
When I only connect the TDIF I/O, the MX initialisation is blocked with MX welcome message on display. Infinite loop....

I check the voltage of each power supply on the motherboard and it is OK, I will say "in an acceptable range".
Yesterday I did some investigation on the initialization sequence or we can say boot:
Looking at the LED on the mother board it seems that it is blocked during initialization of the Digital option board.
I take a look at the architecture (schema from Warren) and two point:
1st) The interface for Digital extention and Analog extention are separate (bus, clock, etc.) it confirmes the the problem is on Digital interface.
2nd) But it don't sound good because Digital interface on mother board and TDIF board are directly provided by FPGA!! I cannot replace them (do not have the equipment to do) There is an buffer for clock and othe signals that I will check to see if every thing is there.

Yesterday I bought a MX chassis working for 100€. I will be able to check the TDIF interface into it. Long tunnel for the moment.

If you have some Service manual, technical note it will help.

PS: I create my Service guide with all information that I will share on the forum.

Best regards
Hervé

 

[witzendoz]

I sent you 4 Dropbox shares, all schematics and all manuals plus mx view for later windows

Cheers

 

[Herve QUEVAL]

MAny thank's, I will download...

 

[Herve QUEVAL]

Hi, some result of my investigation:
IT WORKS grrrr....
I don't know why but looking at the signals with my scope (buffered signal from mother board, doing init test using reset input on the mother board (it is a warm start but OK to init without switching of the main power supply, I discover that it terminate the initialization of the Digital board...

seems boing to cable problem or solder problem.... on Option card side.

 

[Herve QUEVAL]

At the end of the day:
50pin Cable checked, replaced, check connectors solder OK - No change.
Signal between mother board and TDIF I/O board checked: level, rize/fall time OK for low level TTL.
No missing signals when fail.

How it works:
Disconnect TDIF I/O board
Power On MX, Initialization is OK
Then wait 30 s to1mn
power off and connect the TDIF I/O board.
Power on: Init is OK everything works.

I did several reset (using reset input of the mother board. This is a hot resart and never failed.

It seems that the problem is during cold start after power on. It Never starts except if I proceed as decribe here upper.

I focus on the init of the I/O board but could change something after initialization, due to the presence of Digital board. It is not linked to usage of the board. Harware critial timing?

I will stop testing this configuration. I will wait my spare MX to do a test with another mother board... Next week.