Tektronix TDS3012 with red screen after DS1742W-120 battery replacement.  - Page 1
Forum section: electronics / testgear

author: cloco2
author_rank: Newbie
timestamp: October 08, 2025, 02:40:00 am
content: Hello everyone.This is my first post and I hope someone here can help me on this issue.My TDS3012 stopped updating date a while ago, but I ignored it (stupid!).This week, it lost all memory of my settings, and today, when I turned it on, it froze on the splash screen and wouldn't get past this.I did some research and concluded that the DS1742W-120 chip had reached its timeout due to the internal battery being drained.I decided to remove and open the chip to install an external CR-2032. I reinstalled the chip and turned it on to test. It booted up apparently normally, with the self-test OK, but the screen displays red instead of the usual blue.The date still can't be updated, and it loses any memory of the settings I make, after turning off the power. I checked voltage of the CR-2032's and it's fine (3,2V).I believe I lost some vital information, such as the SPC constants. So, I decided to reset the factory settings to see if that would fix the issue, but even that didn't work.Since I'm a bit lost and unsure of what to do next, I wonder if there's a way to resolve this situation? And if so, I'd appreciate it if anyone can help me, please tell me how I should proceed.Thank you!

author: cloco2
author_rank: Newbie
timestamp: October 08, 2025, 01:14:52 pm
content: Here's a picture of the red screen, as I mentioned.This doesn't seem like a very common situation, as I haven't found anyone describing a similar symptom.As I mentioned, resetting or recall factory settings, or even performing a Tek Secure Erase memory, returns the screen to its normal color (blue), but only while the oscilloscope is powered on. Recycling the power returns everything to the same state.Any suggestions are welcome. Thanks!

author: sicco
author_rank: Regular Contributor
timestamp: October 09, 2025, 11:47:27 am
content: Most likely your CMOS RAM inside the DS1742W module is not getting the new battery voltage. Possible causes:* The - of the CR-2032 is not connected to GND (pin 12 I think).* The + of the CR-2032 is not connected so that it does not reach the internal chip inside the potted DS1742W module.* Polarity of battery swapped by accident maybe?* Shorted new battery terminal / leads.* Too much damage done to the DS1742W insides when trying to remove the old coin cell battery inside.

author: cloco2
author_rank: Newbie
timestamp: October 09, 2025, 11:34:17 pm
content: Hello, Sicco.Thank you for your message.Actually, I checked GND with pin 12 and it's ok. The positive terminal of the CR2032 is impossible to check. The polarity is correct and the voltage is 3.2 V, as I mentioned.Possible damage to the internal chip is indeed a possibility I can't rule out.I have already ordered a replacement chip, from ebay, to see how the oscilloscope behaves.

author: TinLethax
author_rank: Regular Contributor
timestamp: October 10, 2025, 12:42:00 am
content: I guess you've got a special Evil Tek scope

author: OYAZI
author_rank: Newbie
timestamp: October 10, 2025, 05:53:18 am
content: Hello,How about running 'Tek Secure Erase Memory' from the utility menu?

author: cloco2
author_rank: Newbie
timestamp: October 10, 2025, 11:21:39 pm
content: Hello OYAZI."As I mentioned, resetting or recall factory settings, or even performing a Tek Secure Erase memory, returns the screen to its normal color (blue), but only while the oscilloscope is powered on. Recycling the power returns everything to the same state".It was one of my first attempts!

author: cloco2
author_rank: Newbie
timestamp: October 10, 2025, 11:27:54 pm
content: Quote from: TinLethax on October 10, 2025, 12:42:00 amYeah, it seems so, eh, eh!!!

author: cloco2
author_rank: Newbie
timestamp: October 16, 2025, 09:49:26 pm
content: UPDATE:Well, I received the new chip today and installed it in the oscilloscope. Operation is back to normal.Now, all that's left is to calibrate it to make sure everything is perfect.Thank you all for your support.Carlos