Solartron 7061-- help needed - Page 1
Forum section: electronics / general

author: rodd
author_rank: Regular Contributor
timestamp: April 16, 2019, 07:17:34 pm
content: Dear All,I happened to put my hands in one of these beasts which seems to be in very good condition.It passes self test and initialize properly, I think (see att 1)The PCB's are in very good shape, so I think no one has tried to mess with this instrument before (att 2)My questios are:1 - The configuration dip switch that is described in the manual has 6 contacts but the one installed in the board just 4.I could not find a adjustment recommendation for it in the service manual2 - Some of the large caps are dated 1987, and one has a 5308 (??!!) date code. (att 3 and 4).Now the recurring question in this forum: Should I replace them?3 - I can't find any date code in the small electrolytics.Are they always printed?4- The always recurring question in this (and other forums):Should I replace them?Will I have to re-calibrate the instrument in case I replace them?

author: schmitt trigger
author_rank: Super Contributor
timestamp: April 16, 2019, 07:34:50 pm
content: Thanks for sharing!These vintage DMMs are a sight to see.One commet though....your photos are either low-res or they are blurred/unfocused. Can't make the lettering an most devices.I believe the forum lurkers here (and myself of course) would appreciate if you re-took the images.My opinion with respect to the electrolytics? I would, at the very least, replace the larger power supply ones. Those are the ones that see the most ripple. And if your voltage regulators are working fine, I don't see a need to re-calibrate anything, although a voltage sanity check can be done in less than a minute.

author: rodd
author_rank: Regular Contributor
timestamp: April 16, 2019, 08:04:51 pm
content: Hi,Thank you for your reply.I would gladly take more photos, but the forum limits the attachment size and I had use a very low resolution.Probably I lowered it too much, since most of the photos here are quite "readable".I will use a tripod and use a higher resolution to increase the quality of the photos.Unfortunately I am travelling tomorrow, so the photos will have to wait until the other weekend, when I will be back home.Regards,Roger

author: pigrew
author_rank: Frequent Contributor
timestamp: April 16, 2019, 08:28:24 pm
content: I was working on a Solartron 7081 last year. I'm assuming similar components are used in it.About half of the capacitors were bad (low capacitance). I suggest replacing all of the electrolytics except perhaps the huge ones. On my boards, none of them leaked. It's cheaper to just replace them all than try to debug issues with the existing ones. Replacing the capacitors should if anything move it closer to its old calibration (unless it's been recalibrated with failing capacitors).I think it also has a NiCd battery for backup? I replaced it with a super-cap and I'm very happy with that mod. The battery has leaked on every meter I've seen photos of.On the 7081, the dip switch is used to set the Baud rate of the serial port.Take a look atmy thread on the 7081

author: rodd
author_rank: Regular Contributor
timestamp: April 26, 2019, 02:13:17 pm
content: Hi Folks,Here are the new pictures.I could not find my tripod, so the photos might be still a little blurry.Please give me feedback if they are acceptable.Regards,Roger

author: grizewald
author_rank: Frequent Contributor
timestamp: May 06, 2019, 06:08:59 am
content: It looks like the battery may have already leaked. It also looks as if it has been replaced at least once already.As a matter of priority, I'd check if it has leaked and if so, remove it, neutralise the alkali with water and spirit vinegar and repair any damage.The other part you should immediately replace is the Schaffner mains selector and input filter. It looks original and these things have a tendency to burst into flames, spitting black potting compound everywhere at the same time. I've replaced the filter in my Solartron meters and I found replacements at Mouser. They're not exactly cheap, but you don't want to deal with the aftermath if it does fail (which it will if it's original and the meter has been powered off for a long time).