Turbo Everdrive V2 does not work in my US Turbo

[bozo55]

Well guys, I spent the better part of the last few hours recapping the Turbo.  I replaced all 16 caps in the system with the Console5 kit.  The caps were all Nichicon and looked to be perfect replacements.

The results...

...

...

No change whatsoever.  The only cap that was not replaced was the one inside the RF modulator, and Console5 does not provide that cap anyway.

My observations/hypotheses...

1.  The system did not perform any differently with the new caps.  I think anyone looking to recap their Turbo will be wasting their time.

2.  Perhaps the system might work better with the Turbo ED if some of the caps were replaced with ones that were of higher capacitance.  Maybe the Turbo pros here could suggest such a mod.

3.  The Turbo ED v2 is a finicky bastard.  Obviously Krikzz did not test it with the US Turbo very thoroughly because I think this is going to be a common problem.

4.  Why some Turbos work fine with it and others don't is beyond me.  Maybe there was a change in the manufacturing process of the US Turbo down the line.  We should try to isolate working units from non-working with serial numbers.  My unit is Serial # 0107255HB

[Desh]

Hmmmm... I have tested my V2 ED in my Duo and it was fine.  I'll get my Turbo out of the box and let you know.  I like the idea of documenting the serial numbers to see if it's a random occurrence or if there may have been some nominal hardware change at some point.

[bozo55]

Hmmmm... I have tested my V2 ED in my Duo and it was fine.  I'll get my Turbo out of the box and let you know.  I like the idea of documenting the serial numbers to see if it's a random occurrence or if there may have been some nominal hardware change at some point.

Cool.  Thanks!

[Sjlewis78]

I have the same issue on both of my TG16 consoles. I was waiting for bozo on krikz forums to see if a cap replacement would help and no dice. Not sure what to try next or do.

[NightWolve]

Kinda doubt a cap replacement would've helped but that should've been done already if you're familiar with the history of NEC consoles. All your caps are likely leaking right now. Do it regardless.

Well, it's too bad about this new design. :/ Seems to work fine in my US TurboExpress (which is practically the same damn thing as the TG-16). I played a few levels of Blazing Lasers with no problems and did quick random loads of other ROMs, nothing thorough though. I guess I should do some more tests before feeling safe.

I only own the TurboExpress and Duo, so hopefully it'll be fine. The TG-16 I won in 1990 died on me at some point, so I threw it away. Anyway, I do like the quick load times, but the main reason I quickly sold my V1 was in the hope this new V2 would support the Arcade Card as krik mulled the idea over but didn't in the end... There's hope Bonknuts and/or elmer might hack a way some day, but that's a longshot I guess.

[elmer]

3.  The Turbo ED v2 is a finicky bastard.  Obviously Krikzz did not test it with the US Turbo very thoroughly because I think this is going to be a common problem.

I think that you've hit the nail on the head there.

The TED2 is krikzz's first design to use a completely different technology based on modern 3.3V chips instead of older 5V chips.

Because of that, the board contains it's own 3.3V power-supply regulator chip ... and so I'd be a little surprised if the problem that you're seeing is because of power issues.

But ... it is probably much more sensitive to signal delay and signal quality issues on the TG16's data and address buses than the old TED1 ... especially since both buses now need to be put through a new 5V-to-3.3V conversion chip which adds it's own delay.

TailChao has already commented on signal issues with the TG16 in his "CD Stupid Card" thread ...

As an aside, I've finally *removed* the region mod in my TG16 since this card now takes care of the only reason I installed it in the first place. However, during that process I did a few quick checks as to how the CD Stupid Card and a real System Card 3.0 react to different propagation delays (either due to wire length or the MC14551s). They both start to fail around the same time (especially with the MC14551s driven with a 5V supply), so I'm not too worried.  But I'll still order the 6ns CPLDs and see if things improve (we're using 15ns right now).

The TG16 has verrry long dataline traces on its mainboard and can be a real jerk in regards to signal integrity. The unmodded white PCE I have seems to run nearly anything. I imagine you Duo owners never have to think about any of this as everything is condensed on one board.

Alright, I just found something seriously messed up:

The reset timing on the PCE and TG16 is different, in that the TG16 will occasionally have the CPU released from reset long before the signal rises on the HuCard slot.

[wilykat]

So NEC's redesigned the already tiny and efficient PCE  to be made larger to appeal to "Bigger is Better" Americans is going to bite Krikzz in his ass.  Still got to wonder what NEC was thinking, spreading out those parts meant longer delay on lines. Could this be why the planned SCSI adapter was never going to work on TG-16 (even with extra RAM added), too long data lines?  I read about it being for Duo only.

Makes me wonder if there's a small spike in TG-16 sale on eBay as people are looking for one that works with their new ED and not realize TG-16 design is the problem.  And spike in PCE and Duo sale for people who are replacing the TG-16 so they can use ED 2.0

[bozo55]

So NEC's redesigned the already tiny and efficient PCE  to be made larger to appeal to "Bigger is Better" Americans is going to bite Krikzz in his ass.  Still got to wonder what NEC was thinking, spreading out those parts meant longer delay on lines. Could this be why the planned SCSI adapter was never going to work on TG-16 (even with extra RAM added), too long data lines?  I read about it being for Duo only.

Makes me wonder if there's a small spike in TG-16 sale on eBay as people are looking for one that works with their new ED and not realize TG-16 design is the problem.  And spike in PCE and Duo sale for people who are replacing the TG-16 so they can use ED 2.0

Nah, I'm hoping Krikzz steps up and addresses this.  Either by allowing people to exchange for another revision or hopefully being able to correct this in firmware somehow.

[Sjlewis78]

Is there a way to test if the signal delay is the root cause? Is there a way to get krikzz to look into this or exchange?

[wilykat]

It may take a good osciloscope, a dual trace model, with one probe on CPU end and another on cart connector end to see what the timing offset looks like.  If it shows significant delay between that 2 points, then the circuit is too long and ED is too "fast" trying to communicate with CPU.  Making it run slower might help.

If the O-scope shows little variation between PCE and TG-16, the issue is not with long trace but something else.  Is there something about TG-16 that is different from PCE and Duo beside the flipped data line and RF modulator with different frequency?

[elmer]

So NEC's redesigned the already tiny and efficient PCE  to be made larger to appeal to "Bigger is Better" Americans is going to bite Krikzz in his ass.  Still got to wonder what NEC was thinking, spreading out those parts meant longer delay on lines.

To keep the analogy appropriate for the 1980's ... it was like having the "Christie Brinkley" of consoles, and choosing to release "Rosanne Barr" instead. 

[Lost Monkey]

i received mine today.  (TED2)

I have 3 U.S. TG's to try it on.  Will do so tonight and report the results with serials.

[Sjlewis78]

The serials on my two that don't work are 0162022HB and 9867404HB

[Lost Monkey]

The serials on my two that don't work are 0162022HB and 9867404HB

Yikes!  Those pretty much look like bookends...

[Sjlewis78]

Ha. Yeah maybe the ones in the middle work?