AznKhmerBoi wrote:I have roughly 100 genesis games cart. From my experience i have had little problems booting the games and for the few that didnt work i used the official sega genesis cleanit cartridge for the cart and it works great! It looks like long genesis cartridge and you just insert the game in a few times and it cleans the innards.
I have 2 dead ones out of about 150 total Genesis games that have passed through my hands and I use electrical contact cleaner and disassemble the carts, so they do happen from time to time. One of them looked brand new.
i didn't think i would have to post in this thread again. but i was wrong.
so i took 2 of my dead carts and replaced the caps in 'em. re-tested the SOBs and nothing is changed: still has the blank screen of death. i thought that maybe my soldering job is shitty-butthole, so i took a working duplicate cart i have and replaced the cap in it. it works like a dream.
i even took fine sand paper to the contacts on the 2 dead carts, re-cleaned them with rubbing alcohol and its the same story: blank screen of death. the only thing i have left to blame now is the resistor.
so how do you know what the resistance is? some of the carts have colored bands, some are just a solid brown color, and one is labeled 1µF. a website calculated the resistance for me based off the colored bands and it came out to be 9.3 kiliohms. and to be honest, i have no idea if this is even correct; the bands are tiny and i am not even sure i am identifying the right color. so when buying replacement resistors do i need to worry about voltage? do i need to worry about the 1µF? do i need a resistor with exactly the same colored bands? can i buy a resistor rated at 10kΩ?
final fight cd wrote:i didn't think i would have to post in this thread again. but i was wrong.
so i took 2 of my dead carts and replaced the caps in 'em. re-tested the SOBs and nothing is changed: still has the blank screen of death. i thought that maybe my soldering job is shitty-butthole, so i took a working duplicate cart i have and replaced the cap in it. it works like a dream.
i even took fine sand paper to the contacts on the 2 dead carts, re-cleaned them with rubbing alcohol and its the same story: blank screen of death. the only thing i have left to blame now is the resistor.
so how do you know what the resistance is? some of the carts have colored bands, some are just a solid brown color, and one is labeled 1µF. a website calculated the resistance for me based off the colored bands and it came out to be 9.3 kiliohms. and to be honest, i have no idea if this is even correct; the bands are tiny and i am not even sure i am identifying the right color. so when buying replacement resistors do i need to worry about voltage? do i need to worry about the 1µF? do i need a resistor with exactly the same colored bands? can i buy a resistor rated at 10kΩ?
What's the label next to the item? Usually C# for capacitor, R# for resistor, and D# for diode.
Resistors need to be the same spec for it to work properly. If you have a multimeter, checking a resistor is ok is easy. The colored bands tell what the spec is.
The µF unit is for capacitor. If you replace one, you have to use the same value in µF.
But the voltage value (in V, Volts) can be over the one of the original capacitor.
When I have a contact cleaned cartridge (or not) that still doesn't work, I make some steam on it with my mouth just before inserting it in the console. Until now, it has always worked.
io. wrote:
When I have a contact cleaned cartridge (or not) that still doesn't work, I make some steam on it with my mouth just before inserting it in the console. Until now, it has always worked.
Welcome to the boards.
Breathing on the cart is a terrible idea. The moisture creates corrosion when it dries, so you end up making the cart and the system worse.
Hobie-wan wrote:Breathing on the cart is a terrible idea. The moisture creates corrosion when it dries, so you end up making the cart and the system worse.
Yes, I know, I rarely do it, just when I'm too impatient to test a game before cleaning it or more rarely when the cleaning did nothing. Anyway, I only do it on a spare MegaDrive console, I use for testing.
Just see this bad idea (I agree with that) as a "maybe last chance" to see a game come back to life
Has any one tried transplanting the mask ROM as I described earlier? Luckily I don't have any dead carts myself, but I'd love to take a stab at this if I did. I'm very curious what the cause is.
FFCD, if you replace the resistor and it STILL doesn't work, you think you can try and swap the mask ROM out? Here's my train of thought: take the mask ROM off the "dead" cart and put it on a compatible cart that's known to be working flawlessly. If the game works, then it really limits what the problem is (resistor, cap, pins, PCB itself). If it doesn't work, then you know the actual mask ROM is dead (which is very unlikely - unless the cart has an EPROM instead of a mask ROM).
i took a known cart that was working. replaced the cap. cart still working. i took the resistor out of a "dead" cart (which also had a replaced cap) and put it in the known working cart. cart still working beautifully.
i will still try replacing the mask ROM for shits and giggles though. but i have a feeling that the games are dead without hope of reviving.
hopefully i won't be having these kinds of troubles when tackling the model 1 sega cd.
If you put the resistor from the "dead" cart on the working cart and it worked, the only thing left would be the pins, the PCB and the mask ROM. I know we talked about this already, but is there ANYTHING on the PCB that looks bad? One bad solder joint on a leg of the mask ROM and it wont work. Any broken traces? Anything at all?
I would definitely put the mask ROM on a working cart and see if it works (you have to use a compatible cart). If it doesn't, although strange, you could just replace it with an EPROM.
so i bought a multimeter that measures capacitance. i thought it would be a good idea to test the capacitors before trying to replace all the caps in the sega cd only to find out it wasn't a cap problem.
and i am a complete idiot. i really don't know what the hell i am doing with it. to get familiar with it i and just to fiddle around with it i took a known working cart and i put the red tip on the positive terminal of the cap and the black tip on the negative terminal of the cap, just as the manual says to. to be honest i was expecting the thing to say, "cap is just awesome" or "cap is shit, buy a new one." unfortunately, that did not happen. numbers were spit out, which means nothing to me.
so how do you know if the cap is bad and need replaced? i am assuming since there are numbers being spit out that the caps are good, right? if nothing is spit out are the caps bad? should i just return the multimeter?
