CSA7404B & TDS7404B repair

[charlyd]

Hi i start i new topic about a the upgraded 7000series tektronix scopes.  the B series.
i got in a couple for repair with complicated problems.
problems i want to share but also talk about so everybody can take there benifits from in the future.
at this moment i got on my bench:
 a CSA7404B  with trigger problems  all channels display a zero.
so i suspect the MAX9601 or something arround this chip.
https://www.eevblog.com/forum/testgear/tek-csa7404-repair-project/msg4331338/#msg4331338
..to be continued

a TDS7404B which doesnt boot up fully.
it give me a power faillure on the ACQ processor.
looking for power rails arround the proc.

a TDS7404B which has  311  errors in  Diagnostics  and Misc 512.
the error 311 indicaties memory chips U554 and U754

[charlyd]

a question for the TDS7404B with the ACQ processor power failure. 
does anybody by all means maybe know the exact location of the cpu on the acq board  (B version).
i mean a lot of heatsinks are covering the real identity of the chips.

can anybody point me to its location?
on the picture seen below....

from my first view i have two visible chips to discover there identity.  the 4 red circles are channel related, yellow is triggering related and in the Middle of the 4 red circles  i guess a dataplexer. so on the left i see
- MM9618-UCB
- Xilinx Spartan XC2S50

[KrudyZ]

I have a spare that I keep for parts for the non-B version of the ACQ board.
There clearly are some differences, but I got the heat sinks off two of the parts, so you can have a look.

[charlyd]

@KrudyZ thanks for your reply but i am looking for the acq Processor location on the B version board. not the old board.

so anybody?

[KrudyZ]

Are you sure there is one?
I would not expect it to be covered by a heat sink.
It could be off-board or a soft core processor in an FPGA...

[charlyd]

Thanks for your reply @KrudyZ.
i don t know really where to find maybe i can better post the error tomorrow. maybe that will point more to the problem thanks real good one.

[coromonadalix]

this is the most complete service manual i've found, "the one with the most pages count"   

haven't found another who beat this one  loll unless i try my luck on Fleabay ??

alas   no schematics

https://ia801302.us.archive.org/26/items/tektronix_TDS7000B/TDS7000B.pdf      348 pages

could give you some insights ....  i have made some cals backups and a few things  from a 7254B,  see the other thread about this series  here

EDIT

I retract myself  this one as 396 pages

https://www.opweb.de/espanol/empresa/Tektronix/TDS7254

[charlyd]

Hi ok there we go today i swapped the PowerPc board out because after the post from yesterday i thought for a moment the problem is maybe not related to the ACQ board....but it is for sure. and the message i get is power failure on ACQ Processor.

see bottom of log
-------------------------------------------------------------------------
updateAcqProcFirmware("dbfs:c:/vxBoot/acqProc.hex")
0x16987e0 (tShell): Program enable command didn't echo back properly.
logTask: 1 log messages lost.
value = 0 = 0x0
     cd "pc:"
value = 0 = 0x0

    raxInitializeDevices
done
0x16987e0 (tShell): (Re)starting Acq Processor
0x16987e0 (tShell): Acq processor powerup failure!
---------------------------------------------------------------------

Code: [Select]

romPost: L2 cache ü
romPost: I am alive .


uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu


romPost: L2 cache turned on.

romPost: MPC107  Walking-one passed.

romPost: MPC107 configuration passed.

romPost: Intel21555 PCITOPCI bridge configuration passed.


romPost: PERFORMING ROM CHECKSUM TEST...

romPost: ROM checksum passed.


romPost: PERFORMING DRAM CELL TEST...

romPost: Enabling data cache...
romPost: Data cache enabled.
romPost: Enabling instruction cache...
romPost: Instruction cache enabled.

romPost: DRAM Cell test passed.

romPost: PERFORMING DRAM MARCH TEST WITH CACHE OFF...
romPost: Disabling data Cache...
romPost: Data cache disabled.
romPost: Disabling instruction cache...
romPost: Instruction cache disabled.
romPost: Writing address to each *address...
romPost: Reading address from each *address...
romPost: DRAM march test passed...

romPost: PERFORMING DRAM MARCH TEST WITH CACHE ON...

romPost: Enabling data cache...
romPost: Data cache enabled.
romPost: Enabling instruction cache...
romPost: Instruction cache enabled.
romPost: Writing address to each *address...
romPost: Reading address from each *address...
romPost: DRAM march test passed...

romPost: PERFORMING DRAM WALKING-ONE  TEST...

romPost: DRAM Walking-one test passed.

romPost: PERFORMING NV-MEMORY WALKING-ONE  TEST...

romPost: NV-MEMORY Walking-one test passed.
romPost: Disabling data Cache...
romPost: Data cache disabled.
romPost: Disabling instruction cache...
romPost: Instruction cache disabled.
romPost: Enabling instruction cache...
romPost: Instruction cache enabled.


romPost: POWER-UP DIAGNOSTIC COMPLETE.

Hel










                            VxWorks System Boot


Copyright 1984-1996  Wind River Systems, Inc.





CPU: Tektronix HPP - IBM 750CXe
Version: 5.3.1
BSP version: 2.0.1.10
Creation date: Sep 30 2003, 07:53:07




Press any key to stop auto-boot...
 0
auto-booting...


boot device          : sm
processor number     : 0
file name            : c:/vxboot/vxWorks.st
inet on backplane (b): 192.168.0.1:ffffff00
host inet (h)        : 192.168.0.2
gateway inet (g)     : 192.168.0.1
flags (f)            : 0x1008
target name (tn)     : tds7000
startup script (s)   : c:/vxboot/topscript.hw

Initializing backplane net with anchor at 0x1e80000... done.
Backplane anchor at 0x1e80000... Attaching network interface sm0... done
done.
Attaching networkPC1 dio device driver installed
 interface lo0... done.
Attaching DIO client... done.
Loading c:/vxboot/vxWorks.st...1773468
Starting at 0x200000...

Host Name: bootHost
User: target
Initializing backplane net with anchor at 0x16e0000... done.
Backplane anchor at 0x16e0000... Attaching network interface sm0... done
done.
PC1 dio device driver installed
Attaching network interface lo0... done.

Adding 6034 symbols for standalone.


 ]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
 ]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
 ]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
      ]]]]]]]]]]]  ]]]]     ]]]]]]]]]]       ]]              ]]]]         (R)
 ]     ]]]]]]]]]  ]]]]]]     ]]]]]]]]       ]]               ]]]]
 ]]     ]]]]]]]  ]]]]]]]]     ]]]]]] ]     ]]                ]]]]
 ]]]     ]]]]] ]    ]]]  ]     ]]]] ]]]   ]]]]]]]]]  ]]]] ]] ]]]]  ]]   ]]]]]
 ]]]]     ]]]  ]]    ]  ]]]     ]] ]]]]] ]]]]]]   ]] ]]]]]]] ]]]] ]]   ]]]]
 ]]]]]     ]  ]]]]     ]]]]]      ]]]]]]]] ]]]]   ]] ]]]]    ]]]]]]]    ]]]]
 ]]]]]]      ]]]]]     ]]]]]]    ]  ]]]]]  ]]]]   ]] ]]]]    ]]]]]]]]    ]]]]
 ]]]]]]]    ]]]]]  ]    ]]]]]]  ]    ]]]   ]]]]   ]] ]]]]    ]]]] ]]]]    ]]]]
 ]]]]]]]]  ]]]]]  ]]]    ]]]]]]]      ]     ]]]]]]]  ]]]]    ]]]]  ]]]] ]]]]]
 ]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
 ]]]]]]]]]]]]]]]]]]]]]]]]]]]]]       Development System
 ]]]]]]]]]]]]]]]]]]]]]]]]]]]]
 ]]]]]]]]]]]]]]]]]]]]]]]]]]]       VxWorks version 5.3.1
 ]]]]]]]]]]]]]]]]]]]]]]]]]]       KERNEL: WIND version 2.5
 ]]]]]]]]]]]]]]]]]]]]]]]]]       Copyright Wind River Systems, Inc., 1984-1997

                               CPU: Tektronix HPP - IBM 750CXe.  Processor #0.
                              Memory Size: 0x2000000.  BSP version 2.0.1.10.
                             WDB: Ready.

done
KERNEL: THERMAL CONTROL INITIATED
Executing startup script c:/vxboot/topscript.hw ...
dbFsIoctl: invalid code 3
    ################### topScript starts ###############################




     cd "dbfs:c:/vxBoot"
value = 0 = 0x0


    pDbDev = ramDevCreate(0, 512, 1152, 1152, 0)
new symbol "pDbDev" added to symbol table.
pDbDev = 0x1692d40: value = 23670112 = 0x1692d60 = pDbDev + 0x20
    pDBfs  = dosFsMkfs("/db", pDbDev)
new symbol "pDBfs" added to symbol table.
pDBfs = 0x1691720: value = 23669856 = 0x1692c60


    ld < TekScope.o
value = 23657440 = 0x168fbe0
    ld < TekScopeSM.o
value = 23660544 = 0x1690800
    copy ("TekScope.DBF", "/db/TekScope.DBF")
value = 0 = 0x0



    loggerInit


Serial No: B010125

value = 21822832 = 0x14cfd70



    overrideFPdefaults()
value = 0 = 0x0

    measurePPCtimebase
value = 0 = 0x0


    registerMemPartitionSizes ( 0x00000000 )
value = 0 = 0x0

    semInitForQueueCheckLogMsg
value = 23661184 = 0x1690a80

    initSysWaiter()
value = 0 = 0x0




    raxInit
value = 0 = 0x0
    paiInit
done
value = 16129500 = 0xf61ddc = PaiBaseRegisterTable + 0x804



    configureACL
SUCCESS
value = 0 = 0x0



    verifyAcqBoardID
value = 0 = 0x0





     tcsLoadTableToNVRAM "pc:c:/vxBoot/setup.tcs"
value = 0 = 0x0
     updateAcqProcFirmware("dbfs:c:/vxBoot/acqProc.hex")
0x16987e0 (tShell): Program enable command didn't echo back properly.
logTask: 1 log messages lost.
value = 0 = 0x0
     cd "pc:"
value = 0 = 0x0

    raxInitializeDevices
done
0x16987e0 (tShell): (Re)starting Acq Processor
0x16987e0 (tShell): Acq processor powerup failure!

[charlyd]

and this is what i found reading the theory of operation.
each channel has its own processor...

so back to post to and look for a general error. like no communication or what ever

[charlyd]

did somebody here ever traced out the power rails on these ACQ boards?

[coromonadalix]

you will have to find the lines ...  like poking on the five pins regulators, trying to find supply lines near some decoupling capacitors  near the ic's   ....

without schematics, it wont be an easy task

some people  probed on the  pcb's interconnect  (between the pcb's) ...  some people reported that removing them and reseating them helped (oxidation)    ...

cant recall if you have voltages tests points written on the pcb

[mikehank]

Here a bit of info on this board

[mikehank]

Acq processor failures usually involve power up the board.  Check all the pins on the interconnect boards on the side between the power supply and the acq board.

[mikehank]

I believe the acq processor is an ATMEL chip toward the front of the board.  I have seen one maybe two be bad

[charlyd]

Hello @MikeHank i did what you suggested and guess what i am missing power rails from J2.   and from what i discovered the +15 and -15 is coming from J2 even as  +5 and -5 volt.
This is a start and doesn t mean my acq board is ok, but let us hope so.

of course thanks for your reply , thats a good one i already saw the amtel chip.

BTW any ideas on the load to Fire up this PSU separate.
startup :  PS_ON#   ---->  GND .   [ J1. pin-c1 <> pin-c4 ]

[mikehank]

I've never had any luck troubleshooting these power supplied.  I usually just bough a power up but defective unit on ebay and swapped out the power supply.

[charlyd]

Ah ok... at this moment i have 2 broken PSUs and a good one as my reference.  i swapped out  about 7x  68uF/35v already . and now they start but still miss sec. outputs. lots of smps circuits.

for the PSUs.... to be continued.

meanwhile:  i worked on fixing 2 out of 3 ACQ boards.  with errors in the logs.
 and i hope to fix the last one also.  3 out of 3 would be great.
but i also have a PowerPc with problems and a backlight inverter with problems.
details will follow later.

[charlyd]

ok this weekend i was fully working on a few TDS7404B i again
one did not have a display and a ACQ error. the other one a broken psu and also ACQ board problems. 

i managed to get the display working the invertor had a blow fuse and thinking that was it. No i also have to swap out components on the powerPC. 
so the PSUs and the ACQ errors are my last errors in these units. for the ACQ boards i ordered some sram chips because of the errors in diagnostic run.  i got errors mem 311 and misc 512. and on the other TDS7404B  even more errors lots mem related.  have to wait for chip to arrive come back on this one.

the PSUs  : 
on (1) psu my T7  is primairy not starting  so no 5 and 15v both  +and -

on a (2) psu i replaced  both primairy FETs  and the 5 parallel 2 ohm resistors. then the psu starts and i can power it on but
when conne tinglazuur a load  on J1  on  5v 3,3v and 12v  a 18ohm.resistor my primairy side burns out.

any tips on one of these two PSUs.?

[mikehank]

No good tips on the PSU's sorry.

MISC error 512 i believe is because a calibration flag is set to fail or does not match the s/n from acq board to PPC board.  I used to remember how to change them but its been a bit....

Maybe someone else remember that. 

The memory callouts are usually pretty good.  I believe each demux has 4 SRAM's and the diag failure is usually one of the 4.

[coromonadalix]

i saw that when you change the acq board vs the power pc board  you have to do some kind of a serial match between them   somewhere in the manuals ... ??

[mikehank]

I believe error 512 can be removed by a factory calibration.  I'm unsure if the performance verification in the service manual will help.

[calibrationfixture]

Hi.

I found this on the Repair of TDS 7000 PSU's. Maybe it is usefull.

Succes

[charlyd]

@calibrationfixture  thanks very much but i already got that one ;-)
if someone has more tips on the secundairy side please drop in...

[charlyd]

This weekend i worked on 2 more TDS7404B version scope both with a defective ACQ board.   after hours i got the first one working and the second one is waiting for test.

i made a layout from all the info i have got. 

location of the SRAM chips both top and bottomside and that in combination with the DEMUX chips en i didn t see all error version but as stated in the library in Demux"X" in blue are predicions.

if there is more info i can add please send me and i will make a layout to help everyone here to easily find the problems;-)

[calibrationfixture]

Hi.

Same Forum another Topic/Thread:

https://www.eevblog.com/forum/testgear/tek-csa7404-repair-project/

Contribution of Xyphro. Page 20, 21 etc. Partly Electric Diagram of TDS 7x04 PSU.

Succes