Required Logitech Z103 (00020) sampli circuit board,

with the price of the unit being so low why bother with a repair.
get a new one

samply clean exposure glase and mirrors carfuly

not sure what board you require . there are several boards in this set and most are no longer available

If these are semi weighted keys here is a cut and paste from a manual:
19. Disassembling the Keyboard Assembly
* After inserting a round stick (Rod: TX000670)
between the frame and the keys, remove the
circuit boards. (Fig. 23)
19-1 GHD EBUS L, MK SUB Circuit Board
(Time required: about 12 minutes)
Remove the seven (7) screws marked [260A]. The
GHD EBUS L and MK SUB circuit boards can then
be removed. (Fig. 24, Photo 5)
19-2 GHD M Circuit Board
(Time required: about 12 minutes)
Remove the five (5) screws marked [260B] and the
screw marked [262]. The GHD M circuit board can
then be removed. (Fig. 24)
19-3 GHD H Circuit Board
(Time required: about 12 minutes)
Remove the four (4) screws marked [260C] and the
screw marked [262]. The GHD H circuit board can
then be removed. (Fig. 24)
* Keys can be removed without removing the
circuit boards.
* After removing the GHD EBUS L, GHD M and
GHD H circuit boards, and the rubber contacts
can then be removed.
19-4 Rubber contact
Remove the GHD circuit board for the involved key.
The rubber contacts can then be removed.

The rod is inserted above the weighted hammer and the bottom of the keys from one end. It appears to be about 1/4 inch diameter dowel and will run the full length of the keyboard. You might use 3 foot ones from each end.

Screws are removed and the boards removed without taking the individual keys out.

This is indicating a problem with the hard drive on the machine or a software fault. If a reboot does not clear the problem check all the connectors between the circuit boards and the hard drive. If it keeps re-appearing then a replacement hard drive or circuit board may be required. A service engineer visit will be required to determine which, if any.

I do not know where to get a replacement keypad, but I just fixed the one that I have. On the surface that comes into contact with the circuit board, the keys have a matt black appearance, except for the malfunctioning volume keys. The volume keys looked glossy. I am guessing that oils from our skin have passed through the rubbery keypads and built up on the inside preventing the keys from activating the contacts on the circuit board. I took some adhesive tape remover solvent with a Qtip and lightly wiped it off the keypad, and it works like new. I first tried isopropyl alcohol, and it did not remove the glossy appearance. I hope this helps you.
JDR

This means that your V995 has repeatedly failed its internal self-calibration procedures. Like the message says, you need to send it to Beltronics for service.

http://logitech-en-amr.custhelp.com/app/answers/detail/a_id/7306

the fuse is soldered in the circuit board in the sub. you have to take the sub apart and get the protective metal cover off the circuit board and un solder the old one. new fuses are found at radio shack they call for a 5a125v fuse.

as time goes buy more of the keys will fail to work, pressing hard on the keys may do some damage to the circuit board inside. you need to remove the batteries any and small screws you can see then pry the two haves apart remove any screws that hold the circuit board to the top half and remove the circuit board to expose the bottom of the key pad you will see a black conductor painted on the bottom of each key button, use a Q-tip dipped in alcohol to clean the black conductor on all the keys then do the same thing to the contact points on the circuit board then rub a pencil eraser over the same contact points on the cicuit board and reclean with alcohol again.
This should fix the problem but it will happen again, and at some point even this won't fix the problem and logitech won't let you buy a new key pad, and that is the point I am at now and for that reason I won't buy another remote from them, I expect more than four years out of this product good luck.