Tektronix THS7xxx Scope Hack/Teardown/Discussion - FW 1.16 found

[harrimansat]

Hi folks,

I have two questions:

Is posible to modify a 730A to work with the options of the 720P with the resistors mod?

This version of wavestar will work with the THS series?

https://www.tek.com/oscilloscope/tds510a-software/wavestar-oscilloscopes

Thanks
Regards

[mk_]

This version of wavestar will work with the THS series?

https://www.tek.com/oscilloscope/tds510a-software/wavestar-oscilloscopes

as the THS-Series is not listed I thnk it will not work with the SW

[harrimansat]

This version of wavestar will work with the THS series?

https://www.tek.com/oscilloscope/tds510a-software/wavestar-oscilloscopes

as the THS-Series is not listed I thnk it will not work with the SW

It works!!!! but only a 9600, at others speeds it hangs, I have tested 2 serial cables

[djnz]

I have saved images from my THS720A to my laptop at 38400 baud rate using a python script that I either wrote myself or found and modified (I forgot what exactly had happened).

See https://www.eevblog.com/forum/testgear/tek-ths720a-portable-scope-teardowndiscussion/msg1108612/#msg1108612 for details.

[HighVoltage]

I posted the WinTek32 software before:

https://www.eevblog.com/forum/testgear/tek-ths720a-portable-scope-teardowndiscussion/msg700940/#msg700940

For screen captures, it works really well.

[yaromka]

Hi all, that is 1.16 FW full flash from my ths720a.

[Zucca]

Thanks yaromka,

I hope to start to work again on this projekt as soon as possible.
This good new is also on the first page.

How did you read out the FW?

[yaromka]

You are welcome. I hope that it will be useful. I just removed IC from board and read data with TL866+.

[BravoV]

As we have the latest firmware now, thanks to yaromka. 

The question is how do we upgrade it, without re-calibration if possible ?

[rvalente]

This is not broken, the polarizer is soooo burnt that looks bronken

Mine is just like yours, got replace this polarizer and sabe this lcd

[rvalente]

Fixed my THS720P screen, these are the steps:

First: buy the polarizer film replacement,  from ebay or any local source

Take the scope apart
Disassembly the LM32P10 LCD, thake the glass + PCB out.
Pull out the polarizers
Clean the residual glue/polarizer, tried many solvents, gasoline worked the best
Clean the fingerprints with rubbing alcohol

Try you polarizer in various angles, check what angle gets the best screen contrast (change the screen contrast on menu also)

Cut the polarizer with a scalpel, a little bigger them the display, scissors will crack the polarizer film.
Trim the excess with the scalpel.

Do a better job than I did, cleaning the back light diffuser.

There you have-it, a working screen for low cost.
 

[rvalente]

My backlight is very dimmed, I believe the lamp is showing its age. Does anyone have replaced the lamp or added a LED upgrade?

[Tiberius1]

Hi Zucca
i have the std ths720 and it has a power supply issue - always draws current around 300ma when off and no batteries
CPU is warm which indicates the unit is on in some way.
The schematics i found on this site seem to be a little different in the power supply section.
My unit seems to be an older version.
Are these units different throughout the models and age of the units in regards to the supply section?
Would anyone have a copy of an older version if available?
Thanks in advance

[Zucca]

If the voltage rails are ok why do you suspect the power supply?
If there is too much current then there is a low impedence path somewhere outside the power supply.

does the unit works properly?

We habe only one schematic version available unfortunately.

[goaty]

Just got a 720A and converted it to 720P thanks to TurboTom.
Wanted to test 730 mode which works also, you get the 1Gsps horizontal, but of course not the bandwidth.
So the samplerate is there if anyone wants to try.

Too bad there is no 730P mode ;-)

[amindavid11]

Do you think its possible to do the same thing with the no A version? THS720 to THS720P?

[harrimansat]

Mod  works in my  ths730 too

[seebeck]

Great!!

[MSS]

Hi! Does anybody know, if it is possible to upgrade THS720(without letters) to the THS720P ?

[djnz]

It looks like I need to change the polarizers of my LCD display.

I tried searching but I do not know what kind of polarizer to get- transmissive or reflective or transflective. Are the polarizers used in mobile phone displays different from the scope's LCD? Could someone please link to suitable polarizers from ebay / AliExpress? Thank you!

[superman13]

It looks like I need to change the polarizers of my LCD display.

I tried searching but I do not know what kind of polarizer to get- transmissive or reflective or transflective. Are the polarizers used in mobile phone displays different from the scope's LCD? Could someone please link to suitable polarizers from ebay / AliExpress? Thank you!

Hi, I have changed polarizer film recently for one my old THS scope... Initially I was thinking that LCD is broken but after disassembling I was surprised that is LCD is still alive... just polarizers burned and lamp was broken...

I have got polarizer film from one friend who uses this film for mobile phones screens... I don'n know exactly which model of film is, but after I have changed film and instead of lamp I have used an LED strip from some tablet... screen was not Black and White but Blue and White 

Stuff with color can be also a trick from different spectrum of LED strip for backlight...

I have attached some photos with screen before and after... and also with LCD without polarizer film...

By the way... getting out of glue from LCD is not the easiest stuff... tried a lot of solvents... best results achieved with Acetone from the lab and a new sharp blade...

Before you glue new polarize film, play with angles and you will see when it is correct placed... Also I have used a Vacuum lamination chamber

P.S. Use some medicinal gloves when removing glue and prepare some cotton pads to remove glue from blade... With acetone this glue does not completely dissolve and then you have to get a new blade...

Good luck!

[giacomo]

Hi guys, i have got a THS710A with the dc current offeset issue, i tried the offset compensation multiple times but it did not solved the problem.

Since i did not have a function gen right now (i recently sold it and waiting for the new one), but i had a TL866 with the TSOP40 adapter i tried to update the firmware from the 1.11 --> 1.16 and do the resistor mods for turn it into a 720P.

The mod and the update are gone perfectly and also after running the offset compensation just one time after the update the dc issue wanishes completly. No recal.


superman13 i have a fluke 105B that has the same problem, i also removed the polarization screen (it has been big pain in the butt), coincedently i removed it in the same way.

Now i have to purchase a new one, if you can get information about where your friend purchase it, i would be interested (in this way hopefully i would not wait one month to get one from china that will not work)

[giovannirat]

Hi giacomo,

can you explain how you did the update exactly? Removed the NVRAM and reprogrammed it or used a new chip?

With the 1.16 firmware from yaromka ?

Thanks for any information.

[giacomo]

can you explain how you did the update exactly? Removed the NVRAM and reprogrammed it or used a new chip?

Yes, i desolderd the AM29F080, reprogrammed and soldered it again. To do that i have used hakko FX-888D (with a flat tip, but i think that any tips would be fine, i have not used a fine one), solder 0.7mm, solder wick, hot air 858D, flux pen. i would highly recomend (even if you have a perfect sight) a magnifying glass, even better a microscope that i did not have.

For desoldering without damaging anything around i followed the steps (but first get confident with your tools):

1) I added a blob of solder on the pins and short all of them, that for mix up new solder (and the flux in it) with the older solder
2) remove the solder with the solder wick, do not push, use a good solder wick with a lot of flux in it, the solder will just flow into the wire
3) add flux again with flux pen
4) set the hot air to minimum air flow and 300°C and point it very close against the chip and remove it

Pay attention to not pull hard the chip while you are trying to remove it or the pads will come with it

5) clean the pads with the solder wick, clean the chip if needed and check for short with the magnifing glass, clean it and the pad with a flux remover.
6) set up the TL866, if you purchase the TSOP32/40/48 adapter from xgecu on alyexpress use the TSOP40A 8 bits adapter, select the ic try to read the old firmware, then update the new one

Now resolder the chip

7) align the pin and put a solder across all of them in order to short all of them, no need to be precise
8 clean your tip, add flux with a flux pen and move the tip slowly and gently against the pin, the excessive solder will accumulate on one side or it will remain stick to the tip
9) use solder wick for the excess of solder and repeat from 8, a couple of times for each side while checking with the magnifing glass or the microscope if there is any short

Remove the resistors.

Time needed around 40 minutes for me.

With the 1.16 firmware from yaromka ?

Yes

[BravoV]

With the 1.16 firmware from yaromka ?

Yes

Thats all I need to hear, thank you.