Fan regulator
This simple mod, originally described by tinhead on EEVBlog forum, is intended to make built-in cooing fan quieter. Typical problem with cooling fans is the noise they make and typical solution is to decrease voltage (and therefore current) to the fan to make it rotate slower. Hantek DSO5000-series oscilloscopes have 3 terminal 12V regulator dedicated for the fan (pointed at by an arrow on the title picture). To change the fan voltage I simply need to replace the regulator marked U7 on the power supply PCB.
Tinhead’s original mod was to replace 7812 (12V) regulator with 7805 (5V). It will work assuming good quality fan. Mine refused to start from 5V so I used MC7808 – a 8V regulator. Another good candidates were 7806 and 7809 but after first try I decided 8V is good enough – the fan is spinning well and the noise level is low.
The following picture shows power supply PCB unscrewed from the chassis and turned upside down. Again, an arrow shows the regulator. The PCB is single layer; replacing the regulator is a simple matter of removing solder with a solder wick, pulling the original regulator out and soldering on the replacement. If everything is at hand, the mod takes about 15 minutes to complete, including testing.
Enjoy!
Oleg.
Bottom side of the PCB
Or… you could put a few diodes in series with the fan lead. Or even a zener diode.
– Steve
Looks like more work to me.
There’s a 24 May 2013 video review of the Tekway DST1102B which from what you say here and what I’ve read elsewhere is hardware identical to the Hantek DSO5102B. The unit reviewed has a vent and place for a fan, but no fan:
http://www.youtube.com/watch?v=GpFjUELk-dM
This makes me wonder if the Hantek DSO5102B even needs a fan then.
They all work better with a fan since several parts are overclocked and generate quite a bit of heat.
Hello .. For those who have this model of oscilloscope would make me very welcome thing if I could communicate that generates the supply voltages, because my power supply and out of service. Thank you very much
Hi Salvatore. I probably have the same trouble with my oscilloscope. Did you find out the supply voltages you were looking for? It could help me to try repair my dead oscilloscope! Thank you
I know there’s potentially a hardware mod of removing some filter capacitors on the front-end, but any idea if the current production lower-end Hanteks (ex. 70Mhz DSO5072P) can still be upgraded to 200Mhz via software (either serially at first to test, or thru flashing the folder name change /dst1102b to /dst1202b using Tools_P_models.zip)
At least one post on the eevblog forum suggests it can be bricked
http://www.eevblog.com/forum/testgear/did-i-brick-my-hantek-oscilloscope-just-2-days-after-purchasing/msg530002/
Hackaday has some good posts on the subject:
http://hackaday.com/2015/10/22/upgrading-rigols-more-expensive-oscilloscopes/
http://hackaday.com/2013/07/02/unlocking-a-rigol-scope-once-again/