Hello dear voltnuts, especially DATRON series 10X1 series owners, while waiting for people to decide getting the connectors for my Solartron 1061, I thought that it will feel alone and got a DATRON 1071 for a reasonable price (for Germany
), sold as: "Working, but sold as defect because but I've had enough replacing the tantalums, everytime I replace one, another one pops and errors appears...". If you search fleabay in German, you'll get plenty of them. Also, "it starts with an error, but if you let it run long enough it will eventually come..."
So the instrument comes (nicely packed, I have to admit) and of course the truth is out there but not here, the instrument starts in hold mode, and produces a cornucopia of errors, from 0L to 7, I think I've seen them all. After reading whatever I could find (and it was a lot) I've disconnected all the boards on the bottom ( DCI, R and ACV ) in turn, all 3 of them were producing errors, finally, just with the DCV ( the upper side ADC board, near the digital board) the device started normally and allowed a zero to be made. So all boards on the bottom are screwed, one way or the other.
The replaced tantalums, BTW, were exactly ONE, on the ACV board, that I found it fully massacred, all the test points, cut and the device was delivered with the connector from it unplugged (also the retaining plastic bracket lost). Also some precision capacitor was touched with the soldering iron and whoever cretin tried to do repairs blocked a trimmer by touching it with the soldering iron. And this is some kind of old shop with a reputation
I fucking HATE the equipment sellers that are trying to do these clumsy miserable repairs and running (semi)permanently some nice device, one moron there even peeled off the label of the "True RMS" specialized chip on the AC board that is really unobtanium, even if it actually has just 5 NPN bipolars, why would one do this, is beyond my human comprehension
. I pray that he didn't destroy it, but chances are that is gone, he seem to have cut the original tantalum and clumsy soldered some ordinary elco on the pins, frakking some other components in the process, it was probably with a soldering iron used for plumbing coper pipes.
The main DCV itself is not fully OK, if left with the inputs floating, it will slowly increase the voltage until some large values and marching for the dreaded Error 0L
.
Naja, I can send it back or I can try to repair it myself, even if my blood pressure will increase everytime I'm looking into these "Pfuscherei", so I have a couple of questions for the more experimented people:
- Tantalum capacitors, is it worth replacing all of them on all the boards, even if they are looking OK, what would be some acceptable brands ?
- All the ELCOS will go, the gang of 6 from the ADC board seem to be a main candidate, and the tired looking ones form the power supply as well, is it worth increasing a bit the values ?
- I've seen in another thread some troubles regarding the rectifiers bridge, is it worth replacing them, they are in rather clumsy to reach position, but if it's recommeded, I'll do it ?
- There is a lot of corrosion on metal parts, ground contacts and such, I believe this must be cleaned to at lest have a faint hope of a low noise and sustainable calibration ?
- Speaking of corrosion, the input terminals are connected with screws and nuts and they are really corroded and actually look like ordinary posts, if I'm to replace them, what do you recommend ?
- The calibration key, does anybody knows where to get one, I don't want to do obvious kludge jobs ?
- Any advice and gotchas are extremely appreciated as it's my first restoration of a (relatively sick) precision instrument.
Best regards,
DC1MC