Do you have a question? Post it now! No Registration Necessary
- Posted on
- Macron (HiPo) MPT-4012/5002 pooter PSU
- who where
June 14, 2009, 5:45 am
rate this thread
Just been asked to look into a batch of these units which all expired the same
day, during power fluctuations and brownouts.
Initial observations are fuse blown, caps all look OK and no signs of distressed
components. Bridging the fuse lights the series lamp fully i.e. short present
on input side. Main suspects are the pair of 2SK2765 FETs.
The trouble with this design - aprtf rom the obvious lack of a schematic - is
the lack of space to access any components. There's arguably a 2mm gap between
heatsinks and the main tfmr, with components mounted under an overhang on the
'sinks. To remove for example one of the FETS would require removing an entire
heatsink assembly with three semis attached.
Before I embark on this probably uneconomic task, I thought I'd ask on the
extremely remote chance that someone may have a schematic for any of this family
of MACRON psu's, as deep googling has turned up zip.
Interestingly, on the HiPo website the -4012 is listed as 115/230V while the PSU
label states only 230V. There is no sign of even the potential for a voltage
selector switch on the pcb trackwork, so I'm forced to wonder if it is one of
those auto-sensing dual voltage types which traditionally get confused and die
during 240V system brownouts.
Re: Macron (HiPo) MPT-4012/5002 pooter PSU
Have seen worse than that in some gear. Most switchmode power
supplies everything is jammed into a small space like you describe.
You have no choice but to just desolder all devices and pull the whole
heatsink assembly out.
If the things use clips to attatch to the heatsink, you may be able to
get them out and use tweezers to remove the device
I had a problem with a series of Panasonic units like that in the
1990s. I simply removed the Triac that was used (when turned on by
the control logic) to change the main filter capacitor pair bank from
series (240v) to voltage doubler. (120v). Never had another problem
(note - Im assuming you will use this on a 240v supply.)
Any arrangement like I have just described is pretty easy to identify,
and deal with except for the very inexperienced
Failing that, you will need to look at external brownout protection.
Im sure such devices are available for commercial electrical
installs. They are needed for things like fridges etc where the
compressor motor can burn out at lower voltages.
If its physically possible to mount, and to wire it to your system, it
might be a good idea to give these MACRON PSUs the boot and use a
regular PC power supply. These normally dont give much trouble, and