Electronics > Repair

HP 3478A: How to read/write cal SRAM

<< < (40/41) > >>

dietert1:
Just managed to save the calibration of our HP 3478A. Thanks to all who contributed!


--- Code: ---HP 3478A calibration data
cadt.de 2024-04-16

cal[0] O
0 @@@ACC A@LDM MJ 255 000133 10C4D 133 1.09637
1 @@@@AD AOALN LO 255 000014 1F1CE 14 1.09058
2 @@@@@B AO@BO ML 255 000002 1F02F 2 1.09019
3 IIIIIC AOMMN IG 255 999993 1FDDE -7 1.08668
4 IIIIII AONAD JF 255 999999 1FE14 -1 1.08814
5 @@@@@@ @@@@@ @@ 0 000000 00000 0 1.00000
6 IIIAIB AO@OC KF 255 999192 1F0F3 -808 1.08993
7 IIIBAH ANDL@ KJ 255 999218 1E4C0 -782 1.08360
8 IIICBE AMCBB LE 255 999325 1D322 -675 1.07322
9 IIIIC@ AMDLD KF 255 999930 1D4C4 -70 1.07364
10 IIIIIC AMOMM IH 255 999993 1DFDD -7 1.06867
11 @@@@@@ ALMEN MB 255 000000 1CD5E 0 1.05748
12 @@@@@@ AMLEL MD 255 000000 1DC5C 0 1.06646
13 @@@@@@ AMNOE LO 255 000000 1DEF5 0 1.06795
14 IIIHCD BMMML J@ 255 999834 2DDDC -166 1.16666
15 IIIIHD BLMND JB 255 999984 2CDE4 -16 1.15684
16 @@@@@@ @@@@@ @@ 0 000000 00000 0 1.00000
17 IIIAIB AO@OC KF 255 999192 1F0F3 -808 1.08993
18 @@@@@@ @@@@@ @@ 0 000000 00000 0 1.00000
cal[248..] @@@@@@@@
--- End code ---

Regards, Dieter

radar_macgyver:

--- Quote from: m k on April 15, 2024, 03:24:21 pm ---Figure 7-G-5 (03478-66501) is the older schematics.
Figure 6-5 (C3478-66501) is the newer one, with 7402.

So your machine has a newer configuration.

--- End quote ---
Got it - however, the documentation is still a bit confusing since the schematics show the NOR gates as U515, while the text(and my board) references U508. In the schematic, U508 is a hex inverter.


--- Quote from: m k on April 15, 2024, 03:24:21 pm ---What kind of U502 you have?
Section 6-25 says that revision D changes it to 28 pin chip.

--- End quote ---
Mine is a 20-pin DIP.

m k:
Seems that your board is at least partially renumbered.
Few pictures would be nice.

Earlier U502 is a ROM chip, maybe it's missing.
Older versions had two MCUs, there analog side has already embedded its code.
Maybe your version has digital side code embedded also.

Your earlier picture has a chip above C512 and U507 is originally placed.
So I'm assuming your board still has both MCUs.

radar_macgyver:
My bad - I thought you were asking about the cal RAM - the program ROM is a 24 pin ceramic DIP, no window and no label. Please see attached image of the board. The battery used is a new one I installed a few days ago, it's a half-AA Lithium cell.

m k:
Yes, documentation is still more than a bit confusing.
I've seen rev C with 28 pin ROM and your machine has 7402 for cal.
Maybe 7402 was also the original design.

Normally board info is under rear inputs.

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod