Author Topic: HP 1980B Oscilloscope repair  (Read 1174 times)

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Offline michoTopic starter

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  • Posts: 1
  • Country: si
HP 1980B Oscilloscope repair
« on: August 19, 2019, 02:45:08 am »
Hi,
I was given an 1980B to have a look at it. Someone tried to repair it before and lost some screws. Also messed up the voltage rails by plugging one connector backwards. And lost almost all of the screws that secure bottom boards to the chassis.

I got it to turn on eventually. But only thing it does, is all front panel lights are on. And if I press Beam find there is a very faint green glow that appears on one side of the CRT. So something is working.

After 8 hours of troubleshooting, I got to a point where I am almost 100% sure that the problem lies on the "processor board". Troubleshooting charts also followed me to this board. I checked around the processor board and one of the masked ROM chips (U18) was boiling hot, where the other one was cool (U17). They are pair and even when I swapped them, the problem followed with a chip. It is an Intel P8355 part.

What do you think?

Is there anyone on the forum that has a parts unit and would be willing to sell me those ROMs?





« Last Edit: August 19, 2019, 02:47:40 am by micho »
 

Offline MarshallPlexi

  • Contributor
  • Posts: 34
  • Country: us
    • Jackson Audio
Re: HP 1980B Oscilloscope repair
« Reply #1 on: November 15, 2024, 08:34:24 am »
Any updates on this? I’m having a similar issue.
Founder/CEO - Jackson Audio, Jackson Ampworks
CEO - Fulltone USA
 

Offline Poroit

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  • Posts: 196
  • Country: au
Re: HP 1980B Oscilloscope repair
« Reply #2 on: November 16, 2024, 05:47:07 am »
G'day Micho,

There is a similar topic running in Test Equipment.
 


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