REPAIR GUIDE - TurboDuo/PC Engine Duo: Total capacitor replacement chart

[Waterclocker]

Reading the sound fix thread now, going to try replacing the radial leaded caps that are next to the vr heatsinks.  Makes sense that the heat could have dried them out.

[thesteve]

they leak
the failure to run on the radial caps is from corrosion
the SMD ones dry out

[MNKyDeth]

I normally buy my caps from Mouser but I was in a bit of a rush and didn't take the time to make out a list for what I needed so I ordered a cap replacement kit from Console5.

My question is related to the cap themselves mostly. I see they included a lot of caps with the right uF values but the voltage ratings are different.

An example is I know a spot needs a 22uF 25v cap but all I have in my kit are 22uF 50v caps. Is it ok to go above the voltage as long as the uF rating is correct?

There are a number of caps that have the same values as the ones on the board just some like the one I mentioned has a rather large voltage difference.

Edit:

Also, is there a way to estimate how long a supercap will last in the Duo's? I am planning on replacing one with a 1.5Farad supercap hoping that it will last longer but I would also like to guestimate it's time for holing a charge so I don't lose my save files if I store my Duo for a while.

[NightWolve]

An example is I know a spot needs a 22uF 25v cap but all I have in my kit are 22uF 50v caps. Is it ok to go above the voltage as long as the uF rating is correct?

Yes sir! Not only is it OK, it's better! I've answered this quite a few times here, spreading my newly acquired Le Steve knowledge.

http://www.pcenginefx.com/forums/index.php?topic=7012.msg298464#msg298464

16 V is OK/safe. The circuit board generally operates at ~5 Volts DC after the power regulator, so capacitors that are rated 10 V or above are safe. But the bigger they are, the better they are: they last longer, handle "ripple" better and sometimes there is power inverting going on so they need to be of higher voltage in that area of the board. This comes at the expense of size and $$$: a 25 V cap is physically bigger and more expensive than a 16 V cap, etc. Anyhow, I was confused about this as well when I got started, but there ya go. When replacing a capacitor, you simply need to match the capacitance value exactly, but the max breakdown voltage can be equal or higher (and higher/bigger is better/safer).

That voltage rating on a capacitor is the max breakdown voltage, meaning, if the circuit runs at or higher than that, the capacitor is gonna start to overheat, break down, be destroyed, etc.

Most electronics run at 5 Volts DC here, so 16V rated or better caps are fine.

Sometimes, you don't want to be too close to the normal operating voltage though - it's always better to go bigger if you got the space and don't care to have paid more $$$!

E.g. I have a power supply for a 19" LCD TV given to me for servicing that had both 5VDC and 12VDC power outputs. The 12VDC area had 16V caps for regulation which broke down and killed the TV. Given the extra heat in the area, the manufacturer went too cheap and should've used 25V rated caps which would've been a little harder to fit given the PCB design, but possible. So only after 3-4 years of service, this new TV was dead for something as simple as a few capacitors...

Here's a video from the EE I learned a few things from:

He has a dumpster diving TV/monitor repair segment/feature. People throwing away TVs and LCDs that mostly failed due to cheap capacitors in the power supply area for reasons like this which he finds/is given for amazingly cheap repairs most anybody can do! Cheap CapXon brands and rated just a bit too close to operating output voltage is a typical reason for failure.

[JoeQuaker]

I really need to get around to replacing the caps in my TurboDuo (the all-black model). Everything still functions fine but the audio is really, really weak.

I just dread starting the job as everything looks so tiny and I've never soldered on anything surface-mounted. I'm more used to replacing caps in things like arcade monitor boards and Commodore 64 floppy drives.

[PunkicCyborg]

Recapped a turbo duo. Kind of a pain in the ass using leaded caps. Next one I do will be all tantalums or ceramics for the SMD smd stuff.

[gahrling]

Hey, new user here

I'm attempting to rescue a Turbo Duo unit from death and stumbled across this guide. I intend to do a full cap replacement as starters before performing an RGB mod, though I may need some assistance.

For the cap replacement I want to go the SMD Tantalum route but I'm a bit uncertain on a couple of things:

1. Case size. Will I be able to get away with case size B for all SMD replacements? For instance the original 22uf and 100uf caps on the pcb have completely different physical sizes, the 100uf having approx double the diameter.

2. Voltage. When shopping around for Tant caps I've seen some listing as 'V' and others as 'V dc'. Can I use both types or is one not recommended for this project?

[thesteve]

as far as tant caps, you want to uprate the voltage
V is VDC
for most of the caps i use ceramic 1206
the 100uf6v i use 100uf 16v tant
47uf use 2 22uf ceramic
everything else is leaded and use aluminum like original

[gtsamour]

I have a question guys...

I replaced all the caps on my PCE Duo with smd caps. Do some 22uF electrolytic caps that are located on both sides of the board (black square ones) also need to be replaced?

I have some 22uF tantalum ones, is it OK to use these instead of the electrolytic ones? I used the same ones for the jailbar fix for pins 41/42, 43 pins of the 6260 chip.



Thanks

[Keith Courage]

[farankoshan]

Has anyone ever updated this thread with definitive voltage ratings for each capacitor?
I’m a little bit confused as to why some sites report differing ratings.

For example, Console5’s list has nothing besides 6v or 16v. Is that accurate to say?
The site does sell a full capacitor set, including capacitors to improve the saving capability, as well as to help with a jailbar fix. But I’m unsure about values now.
Here: https://console5.com/wiki/Turbo_Duo

Meanwhile, GameDoctorHK has varying voltage ratings depending on the capacitor. Could be based on the original ratings that came factory-stock on the unit (but that’s only a guess).
Here: http://gamedoctorhk.com/index.php?main_page=product_info&products_id=1143

[farankoshan]

Has anyone ever updated this thread with definitive voltage ratings for each capacitor?
I’m a little bit confused as to why some sites report differing ratings.

For example, Console5’s list has nothing besides 6v or 16v. Is that accurate to say?
The site does sell a full capacitor set, including capacitors to improve the saving capability, as well as to help with a jailbar fix. But I’m unsure about values now.
Here: https://console5.com/wiki/Turbo_Duo

Meanwhile, GameDoctorHK has varying voltage ratings depending on the capacitor. Could be based on the original ratings that came factory-stock on the unit (but that’s only a guess).
Here: http://gamedoctorhk.com/index.php?main_page=product_info&products_id=1143

I bring this concern up (and I would really appreciate anyone who can shed light on this) because I recently had my cd spindle stop spinning. Unsure what caused it to stop, but I just opted to do a full cap replacement. I followed the GameDoctorHK values, and though my HuCard slot works, my CD spindle and lens still refuse to work. Can a wrong voltage rating on a capacitor cause a malfunction like this?

[Keith Courage]

Voltage can be the same or above the rating needed. Meaning if the cap requires 16v you can use 16v,35v etc....you just can't go lower.

[NightWolve]

You must match the capacitance value, but like he said, the max breakdown voltage can always be rated higher, the higher the better.

If the board runs at 5V, you should use a 16V rated cap, it'll be totally safe, can handle spikes, heat better, etc. I have seen TVs break simply because they used a 16V cap in the power supply to regulate 12V for the backlight screen lamps. The caps overheated and popped at the top. Always better to use a 35V cap on a 12V area, especially near a power supply since you've got all that heat from regulators and transformers.

The only downside is the cap will be bigger and more expensive the higher the rated breakdown voltage is. So if the space is there, use 35V if you can especially if you got cheap Chinese caps. No harm no foul, they'll just last so much longer.

[farankoshan]

You must match the capacitance value, but like he said, the max breakdown voltage can always be rated higher, the higher the better.

If the board runs at 5V, you should use a 16V rated cap, it'll be totally safe, can handle spikes, heat better, etc. I have seen TVs break simply because they used a 16V cap in the power supply to regulate 12V for the backlight screen lamps. The caps overheated and popped at the top. Always better to use a 35V cap on a 12V area, especially near a power supply since you've got all that heat from regulators and transformers.

The only downside is the cap will be bigger and more expensive the higher the rated breakdown voltage is. So if the space is there, use 35V if you can especially if you got cheap Chinese caps. No harm no foul, they'll just last so much longer.

Voltage can be the same or above the rating needed. Meaning if the cap requires 16v you can use 16v,35v etc....you just can't go lower.

Thanks for these notes guys. Will keep that in mind. Big help!

However, although we can go out and buy 35v for virtually everything is space inside the console was no problem (or if availability of those caps wasn't a problem either), for peace of mind & reference, will Red Ghost ever update that capacitor list? He did a great job with the cap list on the PCE CD-ROM2 a while back. I used that and never looked back.

Just so we can have the actual values on hand so we know how much higher voltage ratings we can look for.