BNC 625A firmware

[nidlaX]

On a final note, some brute force reflashing has revealed that the byte at offset 0x601B in the ROM seems to control which model is displayed at boot up and enable pulse/function/arb.

For example, my unit originally has 14, while AwArD_RzD's has 54. Changing it to 55 or 5D results in a BNC 625, while 5E or 5F results in a BNC 625A. If you have a unit that's stable and you just want to enable arb mode, I suggest only editing your own ROM and reflashing instead of flashing over the entire BNC625A ROM that's on here and losing your calibration data.

Tested with V3.3 and V3.5. By the way, if you ever have a bad flash over RS232, you can hold down the Remote key on boot up to enter boot loader code download mode. Boot loader versions I've seen include B2.1 and B2.2.

[Nermash]

Finally  All along I had a feeling that there is a magic byte 
My 625 original FW had 54 value at offset 0x601B (version 3.5), changing it to 5F unlocked the arb functionality.

My unit also experiences lockups, but only once per session, and approximately 60 minutes after power up.

[nidlaX]

My unit also experiences lockups, but only once per session, and approximately 60 minutes after power up.

I'll test V3.3 for a few hours to see how stable it is and compare with V3.5 update.

Your next task is to reverse engineer the BNC 632 ROM so we can all get 31.5 MHz for free.

[nidlaX]

I was asked regarding the schematics for the Telulex SG100, so here they are: http://imgur.com/a/GDnOU

I can't remember where I got the files from originally.

[PepaZdepa]

Finaly, I repaired the generator, but it seems to be a little unstable. I'd like to try older firmware, but all I have is v3.5. Is here someone who would send me the v3.3 for instance, please?
Thanks 

[nidlaX]

Finaly, I repaired the generator, but it seems to be a little unstable. I'd like to try older firmware, but all I have is v3.5. Is here someone who would send me the v3.3 for instance, please?
Thanks 

Alright, here it is! I think this is the stock firmware from my unit, modded to enable the arb functionality. If your generator is unstable due to firmware, I recommend you copy your calibration data from your original firmware to whichever firmware you plan to use. This assumes that you backed it up before you made any changes.

[PepaZdepa]

Thank you man, I'll try it following your recommendations 

[nidlaX]

A warning for those of you who have this unit: CHECK THE CAPS ON THE PSU! My unit's PSU had some leaky caps which probably resulted in an overvoltage condition that blew up the DAC and also killed some portion of the synthesizer!

I believe Meanwell makes a drop-in replacement PSU with +-12V that's pretty cheap. I'm still not sure if there's any reason to use a +-15V PSU when the PCB and schematics all specify 12V.

[AwArD_RzD]

Thanks for the info nidlaX i will check those, i don't use it very often so i think it's a good time to open it and check those cap

Anyone fixed the freeze/crash problem when the unit is power on more that 30-60 min ? It still a pain in the ass when the unit do that in the middle of an experiment but usualy i store the config i'm using and when this happen i unplug the signal cable cycle the power and reload my it, take 10 sec so this don't bother me too much.

I have some picture of the schematic from this unit (maybe from this forum i don't remember where i got them), maybe it's time to give it a go but this is not a big priority on my to do list for now !

Thanks for keeping this little signal generator alive, the spec is not great but the unit is very usefull !

[casinada]

I think the unit overheats. Check some of the components inside. I have the same problem. 

[eevcandies]

Here is a good and informative 625A manual for the B&K clone.

https://www.digikey.com/htmldatasheets/production/642800/0/0/1/4070A-Manual.pdf

I bought 3 of the Berkeley 625A units at some insane price like $150 for all three about 7 years ago & never messed with them (they ended up in random places in the house, one was in a cabinet with rolls of gift wrap, another was buried in some piles of books).   I needed to generate AM outdoors last week & finally gave one a try; it is much lighter than my "big bench" generators & none of my other little generators had internal modulation.   The 625A fired up & was good (ver 3.5)!

[mnementh]

Necro-ing the thread to add some Tech Ref for future generations.

I'm using the SG-100 Schematic linked here to troubleshoot my own B&K 4070A; I've done some cleanup so I could print it legibly and made a denotated version as well. Both are attached here, along with the 8070A-specific version I made for myself.

For those who care, the 4070A is not a clone... it's an outright rebadge of the Berkeley Nucleonics Model 630.

Cheers,

mnem