Tektronix 7854 ROM Upgrade preventing ROM ROT

A huge thank you again for all that continue to Join us in the lab for repairs and alignments. The channel would not exist with out all of you so thank you again for dropping by.

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In this video we get another step closer to doing a calibration/alignment on the 7854 frame. I address the issue of ROM ROT that these scopes suffer from just given their age. The 7854 being the first sampling scope that I am aware of I would like to get one up and running totally for the lab but I have confirmed that both of my units are out of spec when It comes to their alignments. Therefore they both need work.

** Repair exposes the Tech to mains electric and should only be done by trained personal. Errors can be fatal. **

[davidpeterson]

I vote for more than one video!
I have a 7854 that I've been holding off aligning because it is such an intimidating piece of equipment. This intro is great, and I would love to learn more about potential bit-rot. My scope seems to be working fine, but if there's anything I can do to prevent the ROMs becoming corrupted I'd like to know how. And it seems this diagnostic board is worth having, just for the excellent capabilities it brings to the process.
Your videos have helped me understand and perform alignment and calibration of my 465s as well as my cal gear. And what cal gear to accumulate. Yet there's always more to gather and do. That's part of the fun!
Demonstrating the 7854 alignment will be a great addition to your videos.

[jspencerg]

I've recently made first-time visit to the Tek Museum. Great people are still creating useful gear.
I have a request and suggestion after discovering your channel. First, I'm no EE. I'm learning. Using older Tek and HP gear provides me with practical insights from the documentation. So, reading instructions while watching is great. Could you show a little more detail when you do something that is a restorative or "tricks learned" technique? Things we first timers would benefit from.
I also have a goal of implementing a gbib network. Seeing you start and expand connections while demonstrating some nitty-gritty details would be great.
Hope you all are doing well in the new year.

[jenniferwhitewolf]

Could use the link to the 7000 series hoods. I might want to get a few.

This really tells me to not bother putting one of these on my 'to-get' list. In 7000, I use a 7834, an R7844 and a 7104 1gig. I had thought one of these might be fun to add, but for me, these are just lab tools, not a hobby or 'collectable' activity. A 2247A provides rise and fall time, freq & period, cursers, and other digital aids... and a current production Siglent provides heavy math like FFT. I sure like the 7854 concept, but am not prepared to engage in the rite of passage to keep one running. Glad the Vintage Tek guys have the goodies, and others are doing restoration, but I'll pass myself. I will enjoy watching your restoration regardless of how you split it up

[Edisson.]

Beautiful machine, great video. They probably divided video with calibration into analog and digital.

Nice day 🙂 Tom

[chrisabad]

I'll take these video's anyway they come!

[paulcarboneNY]

Oh nice, is that the card that Holder Luben designed a few years back? I didn't realize it was in production.
Your ROMs may not be subject to the rot - I thought it was the earlier purple ceramic ROMs from MOSTEK that were the real culprits (they were on my 5042). It's worth mentioning that the real value of this card, in addition to the diagnostic mode, is that the pin compatible EPROMs that can replace these ROMs are complete unobtanium, and even if sourced, are not programmable by modern programmers that hobbyists would tend to have.

[tuopeeks]

Interesting video, I have the same scope. You have me worried now about the ROMs 🙂, perhaps I should prise them out and make duplicated before too long. Its a tricky call as easy to make faults when it essentially ok.

[_hackwell]

very nice pice of kit! If only I had room in my lab for one of those...

[mr_mopar]

How about a link to the tek forums you mentioned.

[propellerbum]

that really sucks about the damage. maybe next time use a specialized shipper