Cleaning a Datron 4000  - Page 1
Forum section: electronics / repair

author: meandeev
author_rank: Regular Contributor
timestamp: September 01, 2020, 06:52:27 pm
content: I need some advice from the community regarding the cleaning (or not) of a Datron 4000 calibrator.I bought a Datron 4000 from ebay. The device seems rather clean from the outside and the calibrator stickers from 2016 were intact.A raw check of the outputs with a brymen869 multimeter didn´t show abnormalities.Because of a fading diplay I decided to open it.I couldn´t believe, what I saw: The device was very dirty/dusty inside!The most dust resides on the backside (power supply, heatsink, fan), but also on the power-amplifier (see picture).

author: coromonadalix
author_rank: Super Contributor
timestamp: September 01, 2020, 08:57:43 pm
content: Compressed air with controlled pressure would do a good job ? sure the dry pads will help on the bigger surfaces ... cotton swabs ... paint brush ??I would not wet the sensitive board(s) .... until really need to do it .... and have a good dry timeAfter a good cleanup, check for the tantalums and capacitors ... you have threads here and some schematics on ko4bb website

author: garrettm
author_rank: Frequent Contributor
timestamp: September 01, 2020, 10:23:31 pm
content: That sounds like some pretty nasty dust!To be honest, I'm surprised that IPA didn't work. I've had excellent results with using it on all sorts of greasy, gritty, dirty equipment.You could try using Flux-Off or methanol--possibly both? If you try methanol, you would want to do it outside in a well ventilated area, as methanol metabolizes into formaldehyde and formic acid in the human body.The sensitive PCBs with high impedance nodes can be cleaned using a commercial can of compressed air (no oil or water content) or compressed nitrogen. High purity IPA or methanol is also fine to use on these boards. You don't want to use a normal air compressor since they will contaminate the boards with micro droplets of oil.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 01, 2020, 11:02:26 pm
content: Ipa and break cleaner did not remove some gunk ?? wow thats nasty for sure+1 for @garrettm comments, i should have written compressed air canBut i had some problems in rf boards with break cleaners, some of them did leave some residues ... some chemtronics brand pcb cleaners too ...Now i use some aqueous pcb cleaners at my shop, and with hot and demineralized water i does a great job. Not sure for non sealed relays ...

author: meandeev
author_rank: Regular Contributor
timestamp: September 09, 2020, 08:42:45 pm
content: because of your hints and my experience with the power-supply board I cleaned the power-amplifier today (used compressed air some days before to blow away the dust):- desoldered the 3 relays, the trimmer and the switch on the board (all not sealed)- gave it a bath of 99% IPA for 30min (pcb completely submerged in IPA) , used a brushafter that some residue left on the board (I knew it from the power supply-board ...) and so I was brave (or stupid) enough to use- a bath of demineralized water with a drop of dishwashing liquid, also brushed it some time- a LOT of demin. water to wash the detergent away- then an additional bath of new IPA for 1 hour to remove the water a little bit and cleaned it again- used compressed air to blow away the IPAafter this procedure the board looks very clean- now it´s in the oven at 70°C for drying (if water exists somewhere )so it seems that at least some of the dirt is only removable with water based cleaning procedures :-(

author: coromonadalix
author_rank: Super Contributor
timestamp: September 10, 2020, 01:52:08 am
content: ive seen dirt acumulation causing some problems like humidity and moisture ... was turning like a gunk