GDEMU SD Extender Repair
Posted: Mon Sep 11, 2023 12:24 pm
What's good everyone? I've been a huge Dreamcast fan since it's released and is my favorite system of all time.
Recently my DC laser decided to finally fully stop reading discs. I recently ordered a DCEMU from Bitfunx. Along with it I ordered this and came with the SD card extender. After having everything together I noticed it wasn't booting the GDMenu. I removed the SD card extender and inserted the SD card directly into the GDEMU and booted perfectly fine!
At this point I knew it was an issue the the SD extender. I tested continuity on each contact on the PCB to the SD card that plugs into the GDEMU in case there was a break somewhere. Had continuity on everything.
With an exacto knife, I removed the heat shrink tubing from the PCB. I was presented with a resistor (R1) and a tantalum capacitor (C2). Using my DMM I tested the resistor and tested fine. Looking up the capacitor code, it should be 1µF. I tested it for a short and it tested good. Using my hot air station, I removed the cap and tested the capacitance. It was only .28nF! So it wasn't shorted, but the capacitance wasn't even close to what it should be.
I replaced it with a 1µF ceramic capacitor 0805 package. It could have taken a 1206, but 0805 was the largest I had on hand. Note: Ideally, you should replace it with a tantalum capacitor of the same value and size. I'll report back if I have any issues down the road using a standard non-polarized ceramic capacitor. Hooked everything back up and I was presented with the GDMenu! I've been using it a few hours without a single issue so far.
If you have an issue with your SD extender, make sure to check the soldering on the flex cable and the capacitor mentioned. Hopefully this helps someone out there and keep dreaming!
Recently my DC laser decided to finally fully stop reading discs. I recently ordered a DCEMU from Bitfunx. Along with it I ordered this and came with the SD card extender. After having everything together I noticed it wasn't booting the GDMenu. I removed the SD card extender and inserted the SD card directly into the GDEMU and booted perfectly fine!
At this point I knew it was an issue the the SD extender. I tested continuity on each contact on the PCB to the SD card that plugs into the GDEMU in case there was a break somewhere. Had continuity on everything.
With an exacto knife, I removed the heat shrink tubing from the PCB. I was presented with a resistor (R1) and a tantalum capacitor (C2). Using my DMM I tested the resistor and tested fine. Looking up the capacitor code, it should be 1µF. I tested it for a short and it tested good. Using my hot air station, I removed the cap and tested the capacitance. It was only .28nF! So it wasn't shorted, but the capacitance wasn't even close to what it should be.
I replaced it with a 1µF ceramic capacitor 0805 package. It could have taken a 1206, but 0805 was the largest I had on hand. Note: Ideally, you should replace it with a tantalum capacitor of the same value and size. I'll report back if I have any issues down the road using a standard non-polarized ceramic capacitor. Hooked everything back up and I was presented with the GDMenu! I've been using it a few hours without a single issue so far.
If you have an issue with your SD extender, make sure to check the soldering on the flex cable and the capacitor mentioned. Hopefully this helps someone out there and keep dreaming!