With my plans for minimalistic, CW only, RaDAR activities I managed to swop unused equipment for a YouKits HB1A 3 band (40m/30m/20m) QRP trail style radio but needed to give the LCD screen some attention. I considered this to be “bonding time” between myself and the rig. There is not much information on the Net so I decided to document the steps I took to do the replacement an operation that took a nerve racking four hours to do.
I needed to remove the back cover, the control knobs, the PCB retaining screws (2 of) , the nut and screw holding the power transistor in place for heat sinking and also the coax connector.
The module’s connector pins needed to be unsoldered (12 of them) but it was a mission and using a solder sucker didn’t help at all. This is generally a difficult operation as many of us will know.
I was hoping for a dry joint somewhere although the symptoms didn’t agree but I tried anyway as a first line repair without success.
I had to eventually use my Dremel drill with milling bit to cut the module away and use a sharp wire cutter to remove the left over PCB sections from the pins.
I had some coffee before continuing.
The pins needed to be cleaned before they could fit into the holes of the new LCD module. I also used a scribe to try and slightly increase the wire holes sizes on the LCD module thanks to a suggestion by my friend Daryl ZS6DLL. I soldered them lightly into place (Thinking of the next guy that may need to unsolder again one day!!!)
I was wary of applying power but things need to be done and I was relieved to see the new module worked!!!
Unfortunately, once all was reassembled the rig wasn’t putting out any power and not receiving any signals either. But, that’s for the next bonding phase. Fortunately this is a rig that can be repaired by yourself with a little patience and ingenuity, lots of patience!
I suspect (hoping) the problem lies in the vicinity of the BNC coax connector …. I’ll need to redo the PCB to connector connection using a short flylead.
SMD devices are so tiny but fortunately it wasn’t necessary to go to that level, not yet anyway.
The RX / TX problem was caused by a damaged L4 inductor that was damaged during the LCD replacement, a tiny scratch on the component.
If you zoom in on the picture you can see it. (Top left) I temporarily replaced it with a 1.1 uH inductor and the receiver was it’s awesome self again!
Hope someone finds this information helpful one day!
73 de Eddie ZS6BNE