Tektronics TDS754C schematic

[carlton_mick]

Hi
Have a TDS754C with faults, wont boot and know it has faults on the video memory. really need schematics to trace faults on the processor pcb. anybody able to help?

[vaualbus]

No schematics has ever been released to any TDS scope apart from TDS520/544/644 and 544B.
Good luck, if they will never publish them, it would be like find gold.

[carlton_mick]

Vaualbus. Thanks for the info. I am sure many elements will be similar so will search out those you list. I have some problems with dsp memory and info on the I10412-01 daculator.

[cedinu]

IMP I10412 is 16 DACs 12bit. No datasheet AFAIK. You can see the pinout in 1740A WFM service manual.

[nctnico]

Vaualbus. Thanks for the info. I am sure many elements will be similar so will search out those you list. I have some problems with dsp memory and info on the I10412-01 daculator.

Your assumption is correct. You can use the schematics for other oscilloscopes from the same series (start by looking for 'TDS520B component level service manual') to figure out what the problem is. Over time there have been some optimisations but the basic designs are the same. There are quite a few ASICs in these oscilloscopes which would make it hard to make radical changes without needing to do a costly re-design of the ASICs.

[vaualbus]

But the CPU board is completely different on C/D models, they switched to a 68040 CPU so probably the schematics are not correct at all.
Even between 540 and 540A the CPU was redesigned.
I think A and B model CPU are the same maybe?

A.V