I successfully replaced a set of Beomaster 8000 display LEDs with SMD LEDs today. This set was in dire need of repair due to numerous malfunctioning display segments.

Initially, I attempted to use my SMD work station for this task, hoping to refine the method I used for the Beocord 9000 display restoration, which had worked well. However, the SMD work station technique proved less effective this time, requiring more rework and resulting in wasted SMD LEDs.

The issue with the SMD work station is that the SMD LEDs tend to move during soldering, even with minimal air flow. This misalignment occurs frequently, with over half of the LEDs not soldering in the correct position, even on smaller solder pads. Precise LED placement is crucial for these Beosystem LED displays as they need to fit accurately within the slots of the plastic housing that directs the light.

Consequently, I abandoned the experimental approach and went back to the reliable manual soldering process.

To illustrate, the image below shows the Beomaster 8000 channel balance display prepped for soldering. The SMD LEDs are in position on the solder paste, ready for heat application.

The outcome after using the board heater and heat gun to melt the solder was less than ideal.

The LEDs circled in red indicate unsuccessful soldering. These LEDs were discarded as I prefer not to reuse them after removal. The delicate nature of SMD LEDs makes them susceptible to damage and potential future failure.

The image below shows the reworked board following manual repair using traditional tweezers and a soldering iron. Excess solder was removed using a desoldering gun.

Having switched to manual soldering, I prepped the next board, the Beomaster 8000 volume level display, by cleaning it with alcohol and tinning the solder pads.

Prior to placing the SMD LEDs, I used a syringe to apply solder flux. The SMD board heater served as a helpful tool to secure the board during the process.

The image below shows the completed volume level display. I referred to photos from a previous post that documented the LED orientation on the pads, using my smartphone as a reference while placing and soldering the LEDs.

Next was the Beomaster 8000 function display. The image below shows the prepped board.

…and the finished board.

Lastly, the FM frequency display board, which is arguably the most challenging part of the restoration. The intricate work requires a steady hand and patience to avoid frustration.

The image below shows the board prior to tinning. I used a razor knife to cut the small pads where the original LEDs were mounted. Leaving them intact posed a risk of solder bridging due to the narrow gap. Removing them created an optimal space for the SMD LED components.

The following image shows the board after tinning and application of solder flux.

The final board is complete. During the manual soldering, I employed a technique of soldering one side of the SMD LED first to hold it in place. Then, I would test the fit of the light guide to ensure the LED component was centered within the slot. This extra step, while seemingly redundant, helped avoid rework and potential damage to the SMD LED. Once the fit was confirmed, I would proceed to solder the other side of the LED.

Next is the display burn-in test. I modified my test jig from the last time and will be running these displays for 24 hours to ensure they are all functioning correctly.

As a point of reference, the image above shows the progression of the displays. The channel balance display is fully reassembled (temporarily pressed together, not yet permanently fixed), the volume and function displays have the light guide attached, and the FM frequency display is bare.

While these display modules are undergoing testing, I can begin recapping the Beomaster display and Microcomputer boards.