Author Topic: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2  (Read 37911 times)

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Offline vaualbus

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #75 on: January 04, 2014, 03:33:24 pm »
I think that the central asic is not a mux (that indeed should be a demux) but the trigger asic, when dave freaze it the trigger point move and the wave not trigger for a moment.
Is more probably that the mux is near the memory or even inside the main fpga.
 

Offline burra7

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #76 on: January 04, 2014, 04:42:23 pm »
 

Offline burra7

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« Last Edit: January 04, 2014, 06:28:00 pm by burra7 »
 

Offline toomas

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #78 on: January 04, 2014, 10:57:42 pm »
If the adc is 9 bits, then maybe it outputs them all in parallel. If you could locate those pins, then maybe you can probe them or force them to high or low and see what the waveform on the screen does.
 

Offline vaualbus

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #79 on: January 04, 2014, 11:41:36 pm »
Definitly the middle chip is the trigger asic.
Indeed there is this patent associted with that: http://www.google.com.tr/patents/US6219094
 

Offline Fryguy

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #80 on: January 12, 2014, 06:53:57 pm »
Has anyone noticed the "Dallas Timekeeper Ram" chip at the top center of the board ? If i'm not mistaken , these chips will KILL the scopes when the lithium battery inside drops dead !
I remember seeing them on old computer mainboards (i386 + i486) and on gamemachine mainboards . The ram is hooked up to the battery inside the chip - and when the battery voltage has dropped below a certain level , the ram loses it's programm and the machine drops dead - most likely forever .   :-BROKE

If that is the case here , all these scopes will definitely die in 100% working condition . . . and i will stop buying Tek equipment forever . People who put self-destruction-devices in expensive top quality lab equipment deserve the spanish inquisition .  :--

Sorry if i'm a bit emotional on this but nothing drives me as crazy as some a**h***s wasting perfectly good stuff .
May the forces of evil get confused on their way to your home !
 

Offline Hydrawerk

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #81 on: January 12, 2014, 07:22:01 pm »
Oh shit, there is a 3V battery in my DSOX2002A, too. But is there a Dallas-Timekeeper-Ram??
« Last Edit: January 12, 2014, 09:01:18 pm by Hydrawerk »
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Offline Fryguy

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #82 on: January 12, 2014, 07:36:26 pm »
You should feel lucky if you can replace the battery in your scope - The "Dallas-Timekeeper-Ram" or "Dallas-Clock-Chip" was specifically designed to kill the machines . . .

Keyword : planned obsolescence

Seeing the datecodes on the chips (98/99) and knowing the nominal lifespan of the "Dallas" devices is about 10-15 years makes me wonder how long these scopes will continue to work . . .

Did the "Australian Forces" know about it . . . ?
« Last Edit: January 12, 2014, 08:54:14 pm by Fryguy »
May the forces of evil get confused on their way to your home !
 

Offline philpem

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #83 on: January 12, 2014, 09:00:03 pm »
You should feel lucky if you can replace the battery in your scope - The "Dallas-Timekeeper-Ram" or "Dallas-Clock-Chip" was specifically designed to kill the machines . . .

Keyword : planned obsolescence

Seeing the datecodes on the chips (98/99) and knowing the nominal lifespan of the "Dallas" devices is about 10-15 years makes me wonder how long these scopes will continue to work . . .

Did the "Australian Forces" know about it . . . ?

They weren't designed specifically for that reason -- they were designed to maintain data (typically data which is updated often enough to wear out an EEPROM) across power cycles. If the manufacturers choose to use it to store program code or critical data without providing a means to reprogram said data then that's their decision and may hellfire rain upon them for it.
Phil / M0OFX -- Electronics/Software Engineer
"Why do I have a room full of test gear? Why, it saves on the heating bill!"
 

Offline c4757p

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #84 on: January 12, 2014, 09:07:18 pm »
People who put self-destruction-devices in expensive top quality lab equipment deserve the spanish inquisition .  :--

They deserve it, yes, but can you really blame them for not expecting it?
No longer active here - try the IRC channel if you just can't be without me :)
 

Offline Hydrawerk

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #85 on: January 12, 2014, 09:15:40 pm »
Here is the dallas killer scope device. There is probably no similar component in my DSOX2002A. http://www.flickr.com/photos/eevblog/sets/72157626631250619
Amazing machines. https://www.youtube.com/user/denha (It is not me...)
 

Offline Fryguy

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #86 on: January 12, 2014, 09:26:18 pm »
You should feel lucky if you can replace the battery in your scope - The "Dallas-Timekeeper-Ram" or "Dallas-Clock-Chip" was specifically designed to kill the machines . . .

Keyword : planned obsolescence

Seeing the datecodes on the chips (98/99) and knowing the nominal lifespan of the "Dallas" devices is about 10-15 years makes me wonder how long these scopes will continue to work . . .

Did the "Australian Forces" know about it . . . ?

They weren't designed specifically for that reason -- they were designed to maintain data (typically data which is updated often enough to wear out an EEPROM) across power cycles. If the manufacturers choose to use it to store program code or critical data without providing a means to reprogram said data then that's their decision and may hellfire rain upon them for it.

These chips were keeping the bios data on the old computer mainboards - how often was that updated in it's lifetime ? once ? or twice ? that won't wear out an EEPROM . On the gamemachines i've seen the "bios" getting updated literally zero times .

I'm pretty sure they were expecting it at some point c4757p - they put the timebombs in there  ;)

Hydrawerk - the battery is inside the "Dallas" device ( that's why the chip is 3x thicker than the other chips - it contains a RAM chip , a realtime clock chip , a clock crystal and a lithium battery - if i'm not mistaken - i teared some of those chips apart a long time ago ) - if you see a battery , you don't have to look for that chip .

However - i'm curious what Dave's got to say about this huge  :-- .
« Last Edit: January 12, 2014, 09:59:37 pm by Fryguy »
May the forces of evil get confused on their way to your home !
 

Offline vaualbus

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #87 on: January 12, 2014, 11:18:52 pm »
The real name of this chips are nvram,
no volatile ram. In almsot old 80/90 instruments are used to mantained calibration data and information about the instrument options.
This chips not spread acid on the board. They are made by dallas semicondactors, now is maxim (some of this ics still be in free sample on the maxim site indeed) and just not mantain data when the internal battery go away.
There is good reason to not place the calibration data on eeprom sometime calibration is made every time you turn on the intrument (for example in network analyzer) and there is no reason to place the data on a eeprom.
The IC maxim life time is about 10 years but the ic still work also for a longer time (recently I change on of this ic and was made in the late of 92 but still work).
Best regards, Alberto.
 

Offline sync

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #88 on: January 16, 2014, 12:50:04 am »
These chips were keeping the bios data on the old computer mainboards - how often was that updated in it's lifetime ? once ? or twice ? that won't wear out an EEPROM .
They hold the BIOS data. Uncritical data. They didn't contain the BIOS code.
 

Offline EEVBlogViewer

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Please bring your projects to an end
« Reply #89 on: January 22, 2014, 09:20:17 am »
There are a a couple of repair videos in the eevblog - but when its not a damaged fuse it seems that a repair is impossible.
 

Offline EEVblog

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Re: Please bring your projects to an end
« Reply #90 on: January 22, 2014, 09:26:17 am »
There are a a couple of repair videos in the eevblog - but when its not a damaged fuse it seems that a repair is impossible.

That's murphy at work every time.
 

Offline Hydrawerk

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #91 on: May 31, 2014, 04:48:56 pm »
What is going on, Dave?
Amazing machines. https://www.youtube.com/user/denha (It is not me...)
 

Offline SeanB

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #92 on: May 31, 2014, 07:40:34 pm »
The case was worth more than the scope on Ebay?
 

Offline wesphillips

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #93 on: January 12, 2015, 06:37:57 am »
Dave,
  How can you say that the hybrid is working? you didn't check the output of the hybrid when the ch3 timebase setting caused the display to  disappear. I would be interested to see the output of ch3 when there is no display at all for ch3.
 

Offline Monittosan

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Re: EEVblog #565 - Tektronix TDS3054 Oscilloscope Repair - Part 2
« Reply #94 on: January 13, 2015, 10:13:12 am »
The scope sold on ebay for a pretty penny so it may just stay a 3ch scope for now  :-BROKE
 


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