TK-890H, krk-7db to krk-5 question.

[resq229]

I bought a new TK-890h deck, it came with the krk-7db end cap, it was radio 2 of the original set.

I want to use it as a single band, single head. I installed a krk-5 end cap and hooked my head to it. the problem is that it will not power on at all.

I know the problem is the resistors need to be moved around, added or removed. I think I have to move resistor 705 to 602?? is this a 0 Ohm resistor? do I just remove the 705 and solder a jumper across the 602?

Then do I need to solder a jumper across R546 and R661?


its currently in the krk-7db configuration as radio 2 and I want to switch it to krk-5 single band, single head config.

Any help would be great.

 

[mrweather]

Find a copy of the service manual. It has diagrams of the spots on the control unit board that need to be "undone" to turn the radio back to normal.

Basically, you re-install chip resistors (jumpers) at R546 and R661, and move R705 back to R602 (which is a 47k chip resistor).

 

[resq229]

Find a copy of the service manual. It has diagrams of the spots on the control unit board that need to be "undone" to turn the radio back to normal.

Basically, you re-install chip resistors (jumpers) at R546 and R661, and move R705 back to R602 (which is a 47k chip resistor).

I've got the service manual and got confirmation on what I thought was needed, also no problem on soldering the jumpers together but how do I move that tiny 47k chip? does it just unsolder with a needle point iron? or anything special needed to do this?

 

[resq229]

Anyone know the procedure for moving the 47k resistor chip?

 

[mmckenna]

Very carefully.

Small tip soldering iron and a fine pair of tweezers. Having three hands helps, too.
Just enough heat to melt the solder, but not too much or you can damage the traces.

 

[resq229]

Very carefully.

Small tip soldering iron and a fine pair of tweezers. Having three hands helps, too.
Just enough heat to melt the solder, but not too much or you can damage the traces.

Thanks for the info, looks like its going to the shop for the fix, I'm too shaky and don't have the right tools for this one. considering it is a brand new deck I better leave it to the professionals this time. thanks.

 

[mmckenna]

Thanks for the info, looks like its going to the shop for the fix, I'm too shaky and don't have the right tools for this one. considering it is a brand new deck I better leave it to the professionals this time. thanks.

I don't fault you for that decision. Way to easy to mess up if you don't have the right tools.

And don't let someone shame you into trying it. Too expensive.

Used to be I had steady hands and could do this sort of stuff. Not any longer, I don't even try.

 

[Jester580]

I use two irons to remove that chip. In the past, I've found that it worked also to remove the solder on one side of thecomponent, then melt the other and lift that side with the iron. I got lucky and didn't damage any contacts, but now that I have two irons, that's the way to go. That and have a sponge nearby to wipe the component off onto so you don't burn or lose it!