Gedalya Posted February 22, 2022 Share Posted February 22, 2022 I'm looking to replace the capacitor on a Sega Genesis cartridge. I tried looking on line but the disparate information did not leave me feeling confident that I knew what I needed to buy. Does anyone here know what kind of capacitor it is, and for that matter what the resistor as well is? Quote Link to comment Share on other sites More sharing options...
Gedalya Posted February 22, 2022 Author Share Posted February 22, 2022 Here is what the PCB looks like; I presume there are a number of different designs, this one simply has a ROM, a resistor, and a capacitor. Quote Link to comment Share on other sites More sharing options...
emerson Posted February 22, 2022 Share Posted February 22, 2022 Based on the pcb labels C1 and C2 these are both capacitors. Also, through hole resistors almost always use a colored stripe system to indicate their value. I would guess the glass cap on the left is 0.1uf as this is a very common value to place across the supply pins of a digital chip. This could be replaced with a MLCC, or multi layer ceramic capacitor, or standard ceramic disc capacitor. The blue cap on the right is an electrolytic capacitor. It's capacitance value should be a number followed by the letters "uf" and it's voltage value is some numbers followed by the letter "V". Both of these should be printed on the cap itself. These are typically polarized with some type of indication pointing to the negative lead. It is important to install this correctly. Bend the blue cap up to see if the values are on the other side. 1 Quote Link to comment Share on other sites More sharing options...
emerson Posted February 23, 2022 Share Posted February 23, 2022 So I cracked open a few Genesis carts and both my Tengen Ms. Pac-Man and Mortal Kombat II use a 47uf 16v electrolytic and a 0.022uf ceramic. Note that ceramic capacitors are quite reliable. I was servicing a tube amplifier from 1959 over the weekend and the ceramic caps are still within spec. It is typically not necessary to replace them. Also, unlike electrolytics, ceramic caps are not polarized so they can be installed in either direction. I personally like to install components with the values facing upward to avoid situations like the electrolytic in your photo. 1 1 Quote Link to comment Share on other sites More sharing options...
Gedalya Posted February 26, 2022 Author Share Posted February 26, 2022 On 2/22/2022 at 7:12 PM, emerson said: So I cracked open a few Genesis carts and both my Tengen Ms. Pac-Man and Mortal Kombat II use a 47uf 16v electrolytic and a 0.022uf ceramic. Note that ceramic capacitors are quite reliable. I was servicing a tube amplifier from 1959 over the weekend and the ceramic caps are still within spec. It is typically not necessary to replace them. Also, unlike electrolytics, ceramic caps are not polarized so they can be installed in either direction. I personally like to install components with the values facing upward to avoid situations like the electrolytic in your photo. Thank you for this information and more specifically the willingness to open up some carts for comparison; this is exactly what I needed. I took some additional pictures with regards to your first response comments which confirm what you see in when you opened your Tengen carts: Quote Link to comment Share on other sites More sharing options...
Gedalya Posted February 26, 2022 Author Share Posted February 26, 2022 @emerson, I am looking to replace the 47uf 16v electrolytic capacitor; do you know what the capacitance range would be for this? I am looking at vendors who sell these and I see two from mouser but the capacitance ranges are different: One is: 0.47 to 15000µF, The other is: 0.47 to 33000µF These are the datasheets: https://www.mouser.com/datasheet/2/293/e_upw-1219485.pdf https://www.mouser.com/datasheet/2/293/e_uvz-1219460.pdf Perhaps someone else is knowledgeable on this as well and can shed some insight? Quote Link to comment Share on other sites More sharing options...
emerson Posted February 27, 2022 Share Posted February 27, 2022 Thanks for the updated photos. So your electrolytic matches the values in my carts as well. Note the large white stripe with the dash, this is the negative lead indication I described earlier. The ranges you're referring to are all of the available capacitance values for the UPW and UVZ series of capacitors. For example, think of it like a set of drill bits starting from 1/16" and ranging up to 1/2". These series of capacitors start at 0.47uf and range up to either 15000uf or 33000uf. Does that make sense? You specifically want a 47uf 16v cap, which falls within the range of either series you posted above. If you look at either datasheet (I'm using UVZ for example) you see at the bottom right where it says "Type Numbering System" and details how the capacitor part number is derived. If you scroll down even further you find tables of capacitor values sorted first by rated voltages then capacitance. Page 2 of the datasheet has your 47uf 16v cap with part number UVZ1C470MDD. If we break this down with the type numbering system we get: Type - U Series- VZ Voltage - 1C (16v) Capacitance - 470 (47uf) Tolerance - M (20%) Configuration - DD (5mm diameter by 11mm tall) Now look at the part numbers for 470uf and 4700uf. See how the last digit increases by 1 for each order of magnitude? This serves as a multiplier for the first two digits and is common practice for electronic parts numbering in general. I copied the above part number into the search bar at Mouser and was presented with three different options. The only difference between these options is the packaging style, either loose parts in a bag or ammo pack where the leads of each part taped to a strip of cardboard. Heh, unfortunately neither of the parts from your datasheets above are available at this time. There is an "In Stock" filter when searching for parts on Mouser. I found 149 available 47uf 16v 5mm diameter caps there. I consider United Chemi-Con, Kemet, Cornell Dubilier, Vishay, Rubycon, Nichicon, Sprague and Illinois all reliable manufacturers. 1 Quote Link to comment Share on other sites More sharing options...
Gedalya Posted February 27, 2022 Author Share Posted February 27, 2022 5 hours ago, emerson said: Thanks for the updated photos. So your electrolytic matches the values in my carts as well. Note the large white stripe with the dash, this is the negative lead indication I described earlier. The ranges you're referring to are all of the available capacitance values for the UPW and UVZ series of capacitors. For example, think of it like a set of drill bits starting from 1/16" and ranging up to 1/2". These series of capacitors start at 0.47uf and range up to either 15000uf or 33000uf. Does that make sense? You specifically want a 47uf 16v cap, which falls within the range of either series you posted above. If you look at either datasheet (I'm using UVZ for example) you see at the bottom right where it says "Type Numbering System" and details how the capacitor part number is derived. If you scroll down even further you find tables of capacitor values sorted first by rated voltages then capacitance. Page 2 of the datasheet has your 47uf 16v cap with part number UVZ1C470MDD. If we break this down with the type numbering system we get: Type - U Series- VZ Voltage - 1C (16v) Capacitance - 470 (47uf) Tolerance - M (20%) Configuration - DD (5mm diameter by 11mm tall) Now look at the part numbers for 470uf and 4700uf. See how the last digit increases by 1 for each order of magnitude? This serves as a multiplier for the first two digits and is common practice for electronic parts numbering in general. I copied the above part number into the search bar at Mouser and was presented with three different options. The only difference between these options is the packaging style, either loose parts in a bag or ammo pack where the leads of each part taped to a strip of cardboard. Heh, unfortunately neither of the parts from your datasheets above are available at this time. There is an "In Stock" filter when searching for parts on Mouser. I found 149 available 47uf 16v 5mm diameter caps there. I consider United Chemi-Con, Kemet, Cornell Dubilier, Vishay, Rubycon, Nichicon, Sprague and Illinois all reliable manufacturers. Thank you very much!!! Quote Link to comment Share on other sites More sharing options...
Gedalya Posted March 18, 2022 Author Share Posted March 18, 2022 After watching the below video and walking through the steps in it I think I found an issue on my cart; the solution according to the video is the addition of a second resistor to correct the fault but aside from the resistor being 1k it doesn't say anymore. I found two options online that differ only by listed wattage: Option 1 - 1K ohm resistor 1/4w (0.25 Watt) ±1% tolerance Option 2 - 1K ohm resistor 1/2w (0.5Watt) ±1% tolerance Anyone know which to use? @emerson is this something you are familiar with? 4 Quote Link to comment Share on other sites More sharing options...
emerson Posted March 18, 2022 Share Posted March 18, 2022 For this application a 1/4W 5% resistor is plenty sufficient. I suggest buying the resistors from Mouser as you'll pay like $0.10 per resistor, $3.50 residential shipping, and receive name brand parts. 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.