[1000mp] Maintenance and Repair of the Mark V FP-29 PSU

[Mike Schatzberg]

Hello 1000MP Fans:

I received the email below today, from Andy, G7LRR, regarding his experience
with the Mark V outboard power supply.
You may want to update your maintenance practice after reading it.

73 and Happy DXing,

Mike
W2AJI


The PSU on the MKV went bang and it was looking like a new unit was needed
at a cost of £495.00 around $700.00.
Lucky I had friends in the trade that was helpful, as Yaesu UK wanted
£100.00 just to look at it,

In the FP-29 PSU it uses 2 voltages 30volts @ 15 amps and 13.8 @ 5 amps.
With this design it gets very hot and yaesu in their wisdom placed the
cooling fan at the bottom of the unit ¼ inch above this is the CAPS and
transformer around this point is about 600volts DC.

This collects dust like you would not believe, I had a like a cat get a
fluff ball in it which shorted across the caps and diodes solder points and
taking out 2 main IC.

These are what I call Black box units having no part numbers nor info in the
drawing from yaesu and made for yaesu only.

These 2 IC alone cost £150.00 around 275 dollars only so they say from
yaesu.

The IC, s are mounted on a board and cover in black resin making it hard to
fault find and also to see what  the thing does in line.

I had a guy chip all the resin off the IC's and clean them with acid to find
that the parts are £1.50  $2.00 each cheap as chips really.

Yaesu are making loads of money by doing this and repairing at silly rates.

Anyway with that said total cost was £45.00 around $75.00.

So all you guys on Mkv with a External PSU take that cover off and blow it
out with a air bush and get some lacquerer and spay the bottom of the PCB
this will stop dust making a short and costing you loads.


Cheers All

Andy

G7LRR