F3F TIMER PROJECT by Jon Edison

Just a few notes regarding my 'repaired'Hunter 16.

I bought the unit from eBay as a non-runner. Externally the unit looks like new, but the seller had said that for some reason the unit had been immersed in water. This I could verify once I opened up the case. The PCB had verdigris on all the tracks near the battery box. This cleaned off using a soft tooth brush, and whist the board was discoloured, no other damage was visible.

The on-board battery was flat, but I inserted some AA cells anyway to see if anything would happen. Some screen flickering was evident as the battery cap was screwed in, which diminished with each repeated attempt to screw the cap in place. Clearly this strategy was not producing any tangible results, so I eventually removed the onboard battery, recharged and replaced it. A new set of Duracells were inserted, and the battery cap screwed in place with great trepidation. The HUNTER now showed absolutely NO sign of life.

In hindsight, this would be the case of course, as the keyboard apparently had a number on non-functioning keys, one of which was the PWR key. For some reason, I never checked the keyboard, and just assumed it was fully functional. Maybe I was bowled a googly by the water ‘damage’ to the PCB, and hence looked elsewhere for the reasons behind the lack of activity.

However, sometime later, in conversation with one of the HUSKY group members, he said he was running his Hunter16 without the onboard battery. As my unit had shown some spark of life with this battery flat, I decided to give it a try. What a shock, the damn thing fired up seconds after I inserted the main batteries. So much so that I dropped the battery cover before I got it screwed home. Still that was progress. Next time I braced myself to get the cap screwed on properly. I tried again - nothing! I figured that the two large electrolytic capacitors at the top of board may now have some charge on them, so I carefully shorted them out and tried again. Boom, there she goes, a slight pause, then the HUSKY welcome screen.

Now press a few keys and see what happens. Well PWR, PAW and ESC keys not working, together with a number of other keys mainly on the LHS of the keyboard. Now that inspection of the flexible ribbon cable showed several major fractures ( Columns A, B and K damaged ). Despite coating them with some ancient conductive silver paint, connection was not restored. So how could I check whether this PCB would do more than just give me the welcome screen? Figure out the keyboard matrix that’s what.

The matrix looks to have 10 columns, which I have labeled A to K ( no I ), and 11 rows, which I numbered unsurprisingly 1 to 11. Tracing the connections revealed the following matrix :-

  A B C D E F G H J K
1 PWR ESC 2 " 4 $ 0 ) = + 9 ( 8 * 6 ^ PWR
2   1 ! W 3 £ - _ Del O 7 & 5 %  
3   Q A E ' @ 8 P U T  
4   Tab S R 7 Home 9 PgUp : I Y  
5   CapsLock Z D RET 5 L J G  
6   \ F F 4 6 , < K H  
7   Alt   X . > 2   M B  
8   V   C 1 End 3 PgDn Shift N V  
9   Shift # ~ Space 0 Ins Del . # ~ / ? # ~  
10 PAW                 PAW
11 CTRL                 CTRL

Blank Cells either have no connection, I have not been able to determine one, or are duplicates

Now I don’t guarantee this to be perfect, but I can tell you that linking K to 1 briefly will power a Husky ON, and another quick contact will power it OFF again. ( A to 1 appears to do the same )
So armed with this and some working keys, I typed in UTIL <enter>. ( painful believe me ). From the resulting Utils screen I could set the time, date, comms ports etc. Success, I was now confident that this PCB was working sufficiently well for me to try installing it in one of my working Hunters.

WARNING - From my dim and distant past, I do not recommend plugging in non working parts into a working system. What you end up with is a box full of non-working parts! Be warned!!

Well that’s now history; the newly booted up PCB worked a treat in its new home, and is currently running a version of my Model Aircraft Timing programme. But now I have more working innards than I have working cases to but them in. Any one got a spare case?

Jon Edison
Dec 2009

Hunter 2 Keyboard Connection

 

Hunter16 LCD PCB

Hunter16 Main PCB

Keyboard Connector

Husky Hunter16